Other Free Encyclopedias » Science Encyclopedia » Science & Philosophy: A-series and B-series to Ballistic Missiles - Categories Of Ballistic Missile

Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria

cell temperature carbon oxygen

Bacteria are mostly unicellular organisms that lack chlorophyll and are among the smallest living things on earth—only viruses are smaller. Multiplying rapidly under favorable conditions, bacteria can aggregate into colonies of millions or even billions of organisms within a space as small as a drop of water.

The Dutch merchant and amateur scientist Anton van Leeuwenhoek was the first to observe bacteria and other microorganisms. Using single-lens microscopes of his own design, he described bacteria and other microorganisms (calling them "animacules") in a series of letters to the Royal Society of London between 1674 and 1723.

Bacteria are classified as prokaryotes. Broadly, this taxonomic ranking reflects the fact that the genetic material of bacteria is contained in a single, circular chain of deoxyribonucleic acid (DNA) that is not enclosed within a nuclear membrane. The word prokaryote is derived from Greek meaning "prenucleus." Moreover, the DNA of prokaryotes is not associated with the special chromosome proteins called histones, which are found in higher organisms. In addition, prokaryotic cells lack other membrane-bounded organelles, such as mitochondria. Prokaryotes belong to the kingdom Monera. Some scientists have proposed splitting this designation into the kingdoms Eubacteria and Archaebacteria. Eubacteria, or true bacteria, consist of more common species, while Archaebacteria (with the prefix archae—meaning ancient) represent strange bacteria that inhabit very hostile environments. Scientists believe these bacteria are most closely related to the bacteria which lived when the earth was very young. Examples of archaebacteria are those bacteria which currently live in extremely salty environments or extremely hot environments, like geothermal vents of the ocean floor.

Stages of bacterial growth

Under ideal conditions, the growth of a population of bacteria occurs in several stages termed lag, log, stationary, and death.

During the lag phase, active metabolic activity occurs involving synthesis of DNA and enzymes, but no growth. Geometric population growth occurs during the log, or exponential phase, when metabolic activity is most intense and cell reproduction exceeds cell death. Following the log phase, the growth rate slows and the production of new cells equals the rate of cell death. This period, known as the stationary phase, involves the establishment of an equilibrium in population numbers and a slowing of the metabolic activities of individual cells. The stationary phase reflects a change in growing condition—for example, a lack of nutrients and/or the accumulation of waste products.

When the rate of cell deaths exceeds the number of new cells formed, the population equilibrium shifts to a net reduction in numbers and the population enters the death phase, or logarithmic decline phase. The population may diminish until only a few cells remain, or the population may die out entirely.


Temperature and bacteria

The lowest temperature at which a particular species will grow is the minimum growth temperature, while the maximum growth temperature is the highest temperature at which they will grow. The temperature at which their growth is optimal is called the optimum growth temperature. In general, the maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart.

Most bacteria thrive at temperatures at or around that of the human body 98.6°F (37°C), and some, such as Escherichia coli, are normal parts of the human intestinal flora. These organisms are mesophiles (moderate-temperature-loving), with an optimum growth temperature between 77°F (25°C) and 104°F (40°C). Mesophiles have adapted to thrive in temperatures close to that of their host.

Psychrophiles, which prefer cold temperatures, are divided into two groups. One group has an optimal growth temperature of about 59°F (15°C), but can grow at temperatures as low as 32°F (0°C). These organisms live in ocean depths or Arctic regions. Other psychrophiles that can also grow at 32°F (0°C) have an optimal growth temperature between 68°F (20°C) and 86°F (30°C). These organisms, sometimes called psychrotrophs, are often those associated with food spoilage under refrigeration.

Thermophiles thrive in very hot environments, many having an optimum growth temperature between 122°F (50°C) and 140°F (60°C), similar to that of hot springs in Yellowstone National Park. Such organisms thrive in compost piles, where temperatures can rise as high as 140°F (60°C). Extreme thermophiles grow at temperatures above 195°F (91°C). Along the sides of hydrothermal vents on the ocean bottom 217 mi (350 km) north of the Galapagos Islands, for example, bacteria grow in temperatures that can reach 662°F (350°C).


pH and bacteria

Like temperature, pH also plays a role in determining the ability of bacteria to grow or thrive in particular environments. Most commonly, bacteria grow optimally within a narrow range of pH between 6.7 and 7.5.

Acidophiles, however, prefer acidic conditions. For example, Thiobacillus ferrooxidans, which occurs in drainage water from coal mines, can survive at pH 1. Other bacteria, such as Vibrio cholera, the cause of cholera, can thrive at a pH as high as 9.0.


Osmotic pressure and bacteria

Osmotic pressure is another limiting factor in the growth of bacteria. Bacteria are about 80-90% water; they require moisture to grow because they obtain most of their nutrients from their aqueous environment.

Cell walls protect prokaryotes against changes in osmotic pressure over a wide range. However, sufficiently hypertonic media at concentrations greater than those inside the cell (such as 20% sucrose) cause water loss from the cell by osmosis. Fluid leaves the bacteria causing the cell to contract, which, in turn, causes the cell membrane to separate from the overlying cell wall. This process of cell shrinkage is called plasmolysis.

Because plasmolysis inhibits bacterial cell growth, the addition of salts or other solutes to a solution inhibits food spoilage by bacteria, as occurs when meats or fish is salted.

Some types of bacteria, called extreme or obligate halophiles, are adapted to—and require—high salt concentrations, such as found in the Dead Sea, where salt concentrations can reach 30%. Facultative halophiles do not require high salt environments to survive, but are capable of tolerating these conditions. Halophiles can grow in salt concentrations up to 2%, a level that would inhibit the growth of other bacteria. However, some facultative halophiles, such as Halobacterium halobium grow in salt lakes, salt flats, and other environments where the concentration of salts is up to seven times greater than that of the oceans.

When bacteria are placed in hypotonic media with concentrations weaker than the inside of the cell, water tends to enter by osmosis. The accumulation of this water causes the cell to swell and then to burst, a process called osmotic lysis.


Carbon, nitrogen and other growth factors

In addition to water and the correct salt balance, bacteria also require a wide variety of elements, especially carbon, hydrogen, and nitrogen, sulfur and phosphorus, potassium, iron, magnesium and calcium. Growth factors, such as vitamins and pyrimidines and purines (the building blocks of DNA), are also necessary.

Carbon is the fundamental building block of all the organic compounds needed by living things, including nucleic acids, carbohydrates, proteins and fats.

Chemoheterotrophs are bacteria that use organic compounds such as proteins, carbohydrates and lipids as their carbon source, and which use electrons from organic compounds as their energy source. Most bacteria (as well as all fungi, protozoans and animals) are chemoheterotrophs. Chemoautotrophs (for example hydrogen, sulfur, iron, and nitrifying bacteria) use carbon dioxide as their carbon source and electrons from inorganic compounds as their energy source.

Saprophytes are heterotrophs that obtain their carbon from decaying dead organic matter. Many different soil bacteria release plant nitrogen as ammonia (ammonification). Other bacteria, the Nitrosomonas, convert ammonia to nitrite, while Nitrobacter convert nitrite to nitrate. Other bacteria, especially Pseudomonas, convert nitrate to nitrogen gas. These bacteria complement the activity of nitrogen-fixing bacteria (for example, Rhizobium), which fix nitrogen from the atmosphere and make it available to leguminous plants, and Azotobacter, which are also found in fresh and marine waters. Together, the activity of these bacteria underlies the nitrogen cycle, by which the gas is taken up by living organisms, used to make proteins and other organic compounds, returned to the soil during decay, then released into the atmosphere to be reused by living things.

Phototrophs use light as their primary source of energy, but may differ in their carbon sources. Photo-heterotrophs (purple nonsulfur and green nonsulfur bacteria) use organic compounds as their carbon source, while photoautotrophs (for example, photosynthetic green sulfur and purple sulfur bacteria) use carbon dioxide as a source of carbon.


Oxygen may or may not be a requirement for a particular species of bacteria, depending on the type of metabolism used to extract energy from food (aerobic or anaerobic). In all cases, the initial breakdown of glucose to pyruvic acid occurs during glycolysis, which produces a net gain of two molecules of the energy-rich molecule adenosine triphosphate (ATP).


Aerobic bacteria

Aerobic bacteria use oxygen to break down pyruvic acid, releasing much more ATP than is produced during glycolysis during the process known as aerobic respiration. In addition, aerobic bacteria have enzymes such as superoxide dismutase capable of breaking down toxic forms of oxygen, such as superoxide free radicals, which are also formed by aerobic respiration.

During aerobic respiration, enzymes remove electrons from the organic substrate and transfer them to the electron transport chain, which is located in the membrane of the mitochondrion. The electrons are transferred along a chain of electron carrier molecules. At the final transfer position, the electrons combine with atoms of oxygen—the final electron acceptor—which in turn combines with protons (H+) to produce water molecules. Energy, in the form of ATP, is also made here. Along the chain of electron carriers, protons that are pumped across the mitochondrial membrane re-enter the mitochondrion. This flow of electrons across the membrane fuels oxidative phosphorylation, the chemical reaction that adds a phosphate group to adenosine diphosphate (ADP) to produce ATP.

Obligate aerobes must have oxygen in order to live. Facultative aerobes can also exist in the absence of oxygen by using fermentation or anaerobic respiration. Anaerobic respiration and fermentation occur in the absence of oxygen, and produce substantially less ATP than aerobic respiration.


Anaerobic bacteria

Anaerobic bacteria use inorganic substances other than oxygen as a final electron acceptor. For example, Pseudomonas and Bacillus reduce nitrate ion (NO 3 ) to nitrite ion (NO 2 ), nitrous oxide (N2O) or nitrogen gas (N2). Clostridium species, which include those that cause tetanus and botulism, are obligate anaerobes. That is, they are not only unable to use molecular oxygen to produce ATP, but are harmed by toxic forms of oxygen formed during aerobic respiration. Unlike aerobic bacteria, obligate anaerobes lack the ability synthesize enzymes to neutralize these toxic forms of oxygen.



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over 3 years ago

bacteria are living cells; to live they must have four conditions can u tell me what the t and m are please

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almost 3 years ago

Other Free Encyclopedias » Science Encyclopedia » Science & Philosophy: A-series and B-series to Ballistic Missiles - Categories Of Ballistic Missile
Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria

cell temperature carbon oxygen temperatures organisms nitrogen water
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Comparisons of in vitro nitrate reduction, methanogenesis, and fermentation acid profile among rumen bacterial, protozoal and fungal fractions.
INTRODUCTION The main sources of nitrate intake by ruminants are feeds and water. Nitrate in forage has been reported to make up about 37% of total nitrogen (Miyazaki, 1977), especially in green
Recycling of fermented sawdust-based oyster mushroom spent substrate as a feed supplement for postweaning calves.
INTRODUCTION Worldwide cultivation of Pleurotus spp. has greatly increased during the previous few decades (Chang, 1999; Royse, 2002). In Korea, total mushroom production was 158,642 M/T in 2008 of
Cassava in lactating sow diets: I. Effects on milk composition and quality.
INTRODUCTION Cassava root meal (Manihot esculent, Crantz.) is a low-cost basal feed ingredient in the tropics. It has a number of advantages for animal feeding including a high content of soft starch
Concert honors cancer survivors
GURNEE — Sixteen-year cancer survivor and local resident Mary Lou Falk was among more than 1,000 attendees at the 11th annual Concert for Life event held at St. Paul the Apostle Church. She said the

Listen to an audio version of this article.

Bacteria are mostly unicellular organisms that lack chlorophyll and are among the smallest living things on earth—only viruses are smaller. Multiplying rapidly under favorable conditions, bacteria can aggregate into colonies of millions or even billions of organisms within a space as small as a drop of water.

The Dutch merchant and amateur scientist Anton van Leeuwenhoek was the first to observe bacteria and other microorganisms. Using single-lens microscopes of his own design, he described bacteria and other microorganisms (calling them "animacules") in a series of letters to the Royal Society of London between 1674 and 1723.

Bacteria are classified as prokaryotes. Broadly, this taxonomic ranking reflects the fact that the genetic material of bacteria is contained in a single, circular chain of deoxyribonucleic acid (DNA) that is not enclosed within a nuclear membrane. The word prokaryote is derived from Greek meaning "prenucleus." Moreover, the DNA of prokaryotes is not associated with the special chromosome proteins called histones, which are found in higher organisms. In addition, prokaryotic cells lack other membrane-bounded organelles, such as mitochondria. Prokaryotes belong to the kingdom Monera. Some scientists have proposed splitting this designation into the kingdoms Eubacteria and Archaebacteria. Eubacteria, or true bacteria, consist of more common species, while Archaebacteria (with the prefix archae—meaning ancient) represent strange bacteria that inhabit very hostile environments. Scientists believe these bacteria are most closely related to the bacteria which lived when the earth was very young. Examples of archaebacteria are those bacteria which currently live in extremely salty environments or extremely hot environments, like geothermal vents of the ocean floor.
Stages of bacterial growth

Under ideal conditions, the growth of a population of bacteria occurs in several stages termed lag, log, stationary, and death.

During the lag phase, active metabolic activity occurs involving synthesis of DNA and enzymes, but no growth. Geometric population growth occurs during the log, or exponential phase, when metabolic activity is most intense and cell reproduction exceeds cell death. Following the log phase, the growth rate slows and the production of new cells equals the rate of cell death. This period, known as the stationary phase, involves the establishment of an equilibrium in population numbers and a slowing of the metabolic activities of individual cells. The stationary phase reflects a change in growing condition—for example, a lack of nutrients and/or the accumulation of waste products.

When the rate of cell deaths exceeds the number of new cells formed, the population equilibrium shifts to a net reduction in numbers and the population enters the death phase, or logarithmic decline phase. The population may diminish until only a few cells remain, or the population may die out entirely.

Temperature and bacteria

The lowest temperature at which a particular species will grow is the minimum growth temperature, while the maximum growth temperature is the highest temperature at which they will grow. The temperature at which their growth is optimal is called the optimum growth temperature. In general, the maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart.

Most bacteria thrive at temperatures at or around that of the human body 98.6°F (37°C), and some, such as Escherichia coli, are normal parts of the human intestinal flora. These organisms are mesophiles (moderate-temperature-loving), with an optimum growth temperature between 77°F (25°C) and 104°F (40°C). Mesophiles have adapted to thrive in temperatures close to that of their host.

Psychrophiles, which prefer cold temperatures, are divided into two groups. One group has an optimal growth temperature of about 59°F (15°C), but can grow at temperatures as low as 32°F (0°C). These organisms live in ocean depths or Arctic regions. Other psychrophiles that can also grow at 32°F (0°C) have an optimal growth temperature between 68°F (20°C) and 86°F (30°C). These organisms, sometimes called psychrotrophs, are often those associated with food spoilage under refrigeration.

Thermophiles thrive in very hot environments, many having an optimum growth temperature between 122°F (50°C) and 140°F (60°C), similar to that of hot springs in Yellowstone National Park. Such organisms thrive in compost piles, where temperatures can rise as high as 140°F (60°C). Extreme thermophiles grow at temperatures above 195°F (91°C). Along the sides of hydrothermal vents on the ocean bottom 217 mi (350 km) north of the Galapagos Islands, for example, bacteria grow in temperatures that can reach 662°F (350°C).

pH and bacteria

Like temperature, pH also plays a role in determining the ability of bacteria to grow or thrive in particular environments. Most commonly, bacteria grow optimally within a narrow range of pH between 6.7 and 7.5.

Acidophiles, however, prefer acidic conditions. For example, Thiobacillus ferrooxidans, which occurs in drainage water from coal mines, can survive at pH 1. Other bacteria, such as Vibrio cholera, the cause of cholera, can thrive at a pH as high as 9.0.


about 1 year ago

Clint

Um, when did we as humans ever have chloroplasts Oliver? Unless you meant algae and plant cells, then I'd totally agree.


about 1 year ago

Oliver

Mitochondrion and Chloroplasts were believed to be free-living organisms such as Bacteria.

Perhaps photosynthetic bacteria became the chloroplasts found in our cells...


9 months ago

hryt

yjtjjjjjjbhbtyhbbbbbfjhlhdfgjshdfkjghauro;ajshsguayrouihoriuhijkrkgggrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr


4 months ago

maurinesolayao

Although all bacteria share certain structural, genetic, and metabolic characteristics, important biochemical differences exist among the many species of bacteria. These differences permit bacteria to live in many different, and sometimes extreme, environments. For example, some bacteria recycle nitrogen and carbon from decaying organic matter, then release these gases into the atmosphere to be re…

Read more: Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria http://science.jrank.org/pages/714/Bacteria.html#ixzz1RPKY581V


6 months ago

mostafa

what bacteria(3 cases) growth in high tempreture and is pathogenic?


about 1 year ago

Ryan

Jen and fudgie7062 are correct. Bacteria are prokaryotes; therefore, they lack a nucleus and ALL membrane-bound organelles (including mitochondria). Having membrane-bound organelles is one of the major and basic distinctions between prokaryotic and eukaryotic cells.


6 months ago

jwlandhar

ilike this page


10 months ago

sanaullah

jem! if bactaria dont hv mitochordia

so how itdoes

glycolsis?



11 months ago

sara

save it to my e-mail


about 1 year ago

Richard Grant

Error: In text it says "maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart." This should read "..30°F (17°C) apart"





almost 3 years ago

Jen

Umm...why is this article discussing mitochondria under the Aerobic Bacteria subheading???

Bacteria don't have mitochondria!!!!


over 2 years ago

fudgie7062

I agree! The electron transport chain in bacteria and other prokaryotes is included within the membrane, while glycolysis and the citric acid cycle occur in the cytoplasm.



Read more: Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria - JRank Articles http://science.jrank.org/pages/714/Bacteria.html#ixzz1DnIupe2C

Vote down Vote up

over 3 years ago

bacteria...

Vote down Vote up

almost 4 years ago

Jen and fudgie7062 are correct. Bacteria are prokaryotes; therefore, they lack a nucleus and ALL membrane-bound organelles (including mitochondria). Having membrane-bound organelles is one of the major and basic distinctions between prokaryotic and eukaryotic cells.

Vote down Vote up

over 3 years ago

Other Free Encyclopedias » Science Encyclopedia » Science & Philosophy: A-series and B-series to Ballistic Missiles - Categories Of Ballistic Missile
Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria

cell temperature carbon oxygen temperatures organisms nitrogen water
Ads by Google
Stem Cell Research Videos
Ever wanted to see real stem cell
research? Watch now at JoVE
www.JoVE.com
Bacteria culture media
Commonly used growth media LB, TB..
Special media support OD600=30 - 50
www.exptec.com
PeproTech EC Ltd
Cytokines, Chemokines, Interleukins
Antibodies, ELISA Kits
www.peprotechec.com
Future Generation Energy
Bringing 24hr Solar Thermal Power
Generation for a better tomorrow
www.konicaminolta.com
Related Articles

Comparisons of in vitro nitrate reduction, methanogenesis, and fermentation acid profile among rumen bacterial, protozoal and fungal fractions.
INTRODUCTION The main sources of nitrate intake by ruminants are feeds and water. Nitrate in forage has been reported to make up about 37% of total nitrogen (Miyazaki, 1977), especially in green
Recycling of fermented sawdust-based oyster mushroom spent substrate as a feed supplement for postweaning calves.
INTRODUCTION Worldwide cultivation of Pleurotus spp. has greatly increased during the previous few decades (Chang, 1999; Royse, 2002). In Korea, total mushroom production was 158,642 M/T in 2008 of
Cassava in lactating sow diets: I. Effects on milk composition and quality.
INTRODUCTION Cassava root meal (Manihot esculent, Crantz.) is a low-cost basal feed ingredient in the tropics. It has a number of advantages for animal feeding including a high content of soft starch
Concert honors cancer survivors
GURNEE — Sixteen-year cancer survivor and local resident Mary Lou Falk was among more than 1,000 attendees at the 11th annual Concert for Life event held at St. Paul the Apostle Church. She said the

Listen to an audio version of this article.

Bacteria are mostly unicellular organisms that lack chlorophyll and are among the smallest living things on earth—only viruses are smaller. Multiplying rapidly under favorable conditions, bacteria can aggregate into colonies of millions or even billions of organisms within a space as small as a drop of water.

The Dutch merchant and amateur scientist Anton van Leeuwenhoek was the first to observe bacteria and other microorganisms. Using single-lens microscopes of his own design, he described bacteria and other microorganisms (calling them "animacules") in a series of letters to the Royal Society of London between 1674 and 1723.

Bacteria are classified as prokaryotes. Broadly, this taxonomic ranking reflects the fact that the genetic material of bacteria is contained in a single, circular chain of deoxyribonucleic acid (DNA) that is not enclosed within a nuclear membrane. The word prokaryote is derived from Greek meaning "prenucleus." Moreover, the DNA of prokaryotes is not associated with the special chromosome proteins called histones, which are found in higher organisms. In addition, prokaryotic cells lack other membrane-bounded organelles, such as mitochondria. Prokaryotes belong to the kingdom Monera. Some scientists have proposed splitting this designation into the kingdoms Eubacteria and Archaebacteria. Eubacteria, or true bacteria, consist of more common species, while Archaebacteria (with the prefix archae—meaning ancient) represent strange bacteria that inhabit very hostile environments. Scientists believe these bacteria are most closely related to the bacteria which lived when the earth was very young. Examples of archaebacteria are those bacteria which currently live in extremely salty environments or extremely hot environments, like geothermal vents of the ocean floor.
Stages of bacterial growth

Under ideal conditions, the growth of a population of bacteria occurs in several stages termed lag, log, stationary, and death.

During the lag phase, active metabolic activity occurs involving synthesis of DNA and enzymes, but no growth. Geometric population growth occurs during the log, or exponential phase, when metabolic activity is most intense and cell reproduction exceeds cell death. Following the log phase, the growth rate slows and the production of new cells equals the rate of cell death. This period, known as the stationary phase, involves the establishment of an equilibrium in population numbers and a slowing of the metabolic activities of individual cells. The stationary phase reflects a change in growing condition—for example, a lack of nutrients and/or the accumulation of waste products.

When the rate of cell deaths exceeds the number of new cells formed, the population equilibrium shifts to a net reduction in numbers and the population enters the death phase, or logarithmic decline phase. The population may diminish until only a few cells remain, or the population may die out entirely.

Temperature and bacteria

The lowest temperature at which a particular species will grow is the minimum growth temperature, while the maximum growth temperature is the highest temperature at which they will grow. The temperature at which their growth is optimal is called the optimum growth temperature. In general, the maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart.

Most bacteria thrive at temperatures at or around that of the human body 98.6°F (37°C), and some, such as Escherichia coli, are normal parts of the human intestinal flora. These organisms are mesophiles (moderate-temperature-loving), with an optimum growth temperature between 77°F (25°C) and 104°F (40°C). Mesophiles have adapted to thrive in temperatures close to that of their host.

Psychrophiles, which prefer cold temperatures, are divided into two groups. One group has an optimal growth temperature of about 59°F (15°C), but can grow at temperatures as low as 32°F (0°C). These organisms live in ocean depths or Arctic regions. Other psychrophiles that can also grow at 32°F (0°C) have an optimal growth temperature between 68°F (20°C) and 86°F (30°C). These organisms, sometimes called psychrotrophs, are often those associated with food spoilage under refrigeration.

Thermophiles thrive in very hot environments, many having an optimum growth temperature between 122°F (50°C) and 140°F (60°C), similar to that of hot springs in Yellowstone National Park. Such organisms thrive in compost piles, where temperatures can rise as high as 140°F (60°C). Extreme thermophiles grow at temperatures above 195°F (91°C). Along the sides of hydrothermal vents on the ocean bottom 217 mi (350 km) north of the Galapagos Islands, for example, bacteria grow in temperatures that can reach 662°F (350°C).

pH and bacteria

Like temperature, pH also plays a role in determining the ability of bacteria to grow or thrive in particular environments. Most commonly, bacteria grow optimally within a narrow range of pH between 6.7 and 7.5.

Acidophiles, however, prefer acidic conditions. For example, Thiobacillus ferrooxidans, which occurs in drainage water from coal mines, can survive at pH 1. Other bacteria, such as Vibrio cholera, the cause of cholera, can thrive at a pH as high as 9.0.

Vote down Vote up

almost 6 years ago

Umm...why is this article discussing mitochondria under the Aerobic Bacteria subheading???

Bacteria don't have mitochondria!!!!

Vote down Vote up

almost 3 years ago

Other Free Encyclopedias » Science Encyclopedia » Science & Philosophy: A-series and B-series to Ballistic Missiles - Categories Of Ballistic Missile
Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria

cell temperature carbon oxygen temperatures organisms nitrogen water
Ads by Google
Stem Cell Research Videos
Ever wanted to see real stem cell
research? Watch now at JoVE
www.JoVE.com
Bacteria culture media
Commonly used growth media LB, TB..
Special media support OD600=30 - 50
www.exptec.com
PeproTech EC Ltd
Cytokines, Chemokines, Interleukins
Antibodies, ELISA Kits
www.peprotechec.com
Future Generation Energy
Bringing 24hr Solar Thermal Power
Generation for a better tomorrow
www.konicaminolta.com
Related Articles

Comparisons of in vitro nitrate reduction, methanogenesis, and fermentation acid profile among rumen bacterial, protozoal and fungal fractions.
INTRODUCTION The main sources of nitrate intake by ruminants are feeds and water. Nitrate in forage has been reported to make up about 37% of total nitrogen (Miyazaki, 1977), especially in green
Recycling of fermented sawdust-based oyster mushroom spent substrate as a feed supplement for postweaning calves.
INTRODUCTION Worldwide cultivation of Pleurotus spp. has greatly increased during the previous few decades (Chang, 1999; Royse, 2002). In Korea, total mushroom production was 158,642 M/T in 2008 of
Cassava in lactating sow diets: I. Effects on milk composition and quality.
INTRODUCTION Cassava root meal (Manihot esculent, Crantz.) is a low-cost basal feed ingredient in the tropics. It has a number of advantages for animal feeding including a high content of soft starch
Concert honors cancer survivors
GURNEE — Sixteen-year cancer survivor and local resident Mary Lou Falk was among more than 1,000 attendees at the 11th annual Concert for Life event held at St. Paul the Apostle Church. She said the

Listen to an audio version of this article.

Bacteria are mostly unicellular organisms that lack chlorophyll and are among the smallest living things on earth—only viruses are smaller. Multiplying rapidly under favorable conditions, bacteria can aggregate into colonies of millions or even billions of organisms within a space as small as a drop of water.

The Dutch merchant and amateur scientist Anton van Leeuwenhoek was the first to observe bacteria and other microorganisms. Using single-lens microscopes of his own design, he described bacteria and other microorganisms (calling them "animacules") in a series of letters to the Royal Society of London between 1674 and 1723.

Bacteria are classified as prokaryotes. Broadly, this taxonomic ranking reflects the fact that the genetic material of bacteria is contained in a single, circular chain of deoxyribonucleic acid (DNA) that is not enclosed within a nuclear membrane. The word prokaryote is derived from Greek meaning "prenucleus." Moreover, the DNA of prokaryotes is not associated with the special chromosome proteins called histones, which are found in higher organisms. In addition, prokaryotic cells lack other membrane-bounded organelles, such as mitochondria. Prokaryotes belong to the kingdom Monera. Some scientists have proposed splitting this designation into the kingdoms Eubacteria and Archaebacteria. Eubacteria, or true bacteria, consist of more common species, while Archaebacteria (with the prefix archae—meaning ancient) represent strange bacteria that inhabit very hostile environments. Scientists believe these bacteria are most closely related to the bacteria which lived when the earth was very young. Examples of archaebacteria are those bacteria which currently live in extremely salty environments or extremely hot environments, like geothermal vents of the ocean floor.
Stages of bacterial growth

Under ideal conditions, the growth of a population of bacteria occurs in several stages termed lag, log, stationary, and death.

During the lag phase, active metabolic activity occurs involving synthesis of DNA and enzymes, but no growth. Geometric population growth occurs during the log, or exponential phase, when metabolic activity is most intense and cell reproduction exceeds cell death. Following the log phase, the growth rate slows and the production of new cells equals the rate of cell death. This period, known as the stationary phase, involves the establishment of an equilibrium in population numbers and a slowing of the metabolic activities of individual cells. The stationary phase reflects a change in growing condition—for example, a lack of nutrients and/or the accumulation of waste products.

When the rate of cell deaths exceeds the number of new cells formed, the population equilibrium shifts to a net reduction in numbers and the population enters the death phase, or logarithmic decline phase. The population may diminish until only a few cells remain, or the population may die out entirely.

Temperature and bacteria

The lowest temperature at which a particular species will grow is the minimum growth temperature, while the maximum growth temperature is the highest temperature at which they will grow. The temperature at which their growth is optimal is called the optimum growth temperature. In general, the maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart.

Most bacteria thrive at temperatures at or around that of the human body 98.6°F (37°C), and some, such as Escherichia coli, are normal parts of the human intestinal flora. These organisms are mesophiles (moderate-temperature-loving), with an optimum growth temperature between 77°F (25°C) and 104°F (40°C). Mesophiles have adapted to thrive in temperatures close to that of their host.

Psychrophiles, which prefer cold temperatures, are divided into two groups. One group has an optimal growth temperature of about 59°F (15°C), but can grow at temperatures as low as 32°F (0°C). These organisms live in ocean depths or Arctic regions. Other psychrophiles that can also grow at 32°F (0°C) have an optimal growth temperature between 68°F (20°C) and 86°F (30°C). These organisms, sometimes called psychrotrophs, are often those associated with food spoilage under refrigeration.

Thermophiles thrive in very hot environments, many having an optimum growth temperature between 122°F (50°C) and 140°F (60°C), similar to that of hot springs in Yellowstone National Park. Such organisms thrive in compost piles, where temperatures can rise as high as 140°F (60°C). Extreme thermophiles grow at temperatures above 195°F (91°C). Along the sides of hydrothermal vents on the ocean bottom 217 mi (350 km) north of the Galapagos Islands, for example, bacteria grow in temperatures that can reach 662°F (350°C).

pH and bacteria

Like temperature, pH also plays a role in determining the ability of bacteria to grow or thrive in particular environments. Most commonly, bacteria grow optimally within a narrow range of pH between 6.7 and 7.5.

Acidophiles, however, prefer acidic conditions. For example, Thiobacillus ferrooxidans, which occurs in drainage water from coal mines, can survive at pH 1. Other bacteria, such as Vibrio cholera, the cause of cholera, can thrive at a pH as high as 9.0.


about 1 year ago

Clint

Um, when did we as humans ever have chloroplasts Oliver? Unless you meant algae and plant cells, then I'd totally agree.


about 1 year ago

Oliver

Mitochondrion and Chloroplasts were believed to be free-living organisms such as Bacteria.

Perhaps photosynthetic bacteria became the chloroplasts found in our cells...


9 months ago

hryt

yjtjjjjjjbhbtyhbbbbbfjhlhdfgjshdfkjghauro;ajshsguayrouihoriuhijkrkgggrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr


4 months ago

maurinesolayao

Although all bacteria share certain structural, genetic, and metabolic characteristics, important biochemical differences exist among the many species of bacteria. These differences permit bacteria to live in many different, and sometimes extreme, environments. For example, some bacteria recycle nitrogen and carbon from decaying organic matter, then release these gases into the atmosphere to be re…

Read more: Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria http://science.jrank.org/pages/714/Bacteria.html#ixzz1RPKY581V


6 months ago

mostafa

what bacteria(3 cases) growth in high tempreture and is pathogenic?


about 1 year ago

Ryan

Jen and fudgie7062 are correct. Bacteria are prokaryotes; therefore, they lack a nucleus and ALL membrane-bound organelles (including mitochondria). Having membrane-bound organelles is one of the major and basic distinctions between prokaryotic and eukaryotic cells.


6 months ago

jwlandhar

ilike this page


10 months ago

sanaullah

jem! if bactaria dont hv mitochordia

so how itdoes

glycolsis?



11 months ago

sara

save it to my e-mail


about 1 year ago

Richard Grant

Error: In text it says "maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart." This should read "..30°F (17°C) apart"





almost 3 years ago

Jen

Umm...why is this article discussing mitochondria under the Aerobic Bacteria subheading???

Bacteria don't have mitochondria!!!!


over 2 years ago

fudgie7062

I agree! The electron transport chain in bacteria and other prokaryotes is included within the membrane, while glycolysis and the citric acid cycle occur in the cytoplasm.



Read more: Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria - JRank Articles http://science.jrank.org/pages/714/Bacteria.html#ixzz1DnIupe2C

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over 3 years ago

yjtjjjjjjbhbtyhbbbbbfjhlhdfgjshdfkjghauro;ajshsguayrouihoriuhijkrkgggrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr

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over 6 years ago

the maximum and minimum temperatures at which a given bacteria can survive differ by about 30F, or about 17C. this site lists the corresponding temperature to 30F (-1C) rather than the corresponding temperature DIFFERENCE (17C). just a small typo.

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about 1 year ago

characteristics of bacteria

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over 3 years ago

I used this article for my research paper about bacteria. I found it very helpful!

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almost 4 years ago

GOOD TOPIC FOR FOOD TECHNOLOGY STUDENTS

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over 3 years ago

ilike this page

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over 3 years ago

asssssscfweagqrajatj

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almost 4 years ago

Um, when did we as humans ever have chloroplasts Oliver? Unless you meant algae and plant cells, then I'd totally agree.

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almost 4 years ago

Mitochondrion and Chloroplasts were believed to be free-living organisms such as Bacteria.

Perhaps photosynthetic bacteria became the chloroplasts found in our cells...

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over 4 years ago

bacteria DO have mitochondria, just not a nucleus, jen. i am 12 but we read that in science ystrday!!! im lookin up things 4 my test.

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about 3 years ago

Although all bacteria share certain structural, genetic, and metabolic characteristics, important biochemical differences exist among the many species of bacteria. These differences permit bacteria to live in many different, and sometimes extreme, environments. For example, some bacteria recycle nitrogen and carbon from decaying organic matter, then release these gases into the atmosphere to be re…

Read more: Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria http://science.jrank.org/pages/714/Bacteria.html#ixzz1RPKY581V

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over 3 years ago

what bacteria(3 cases) growth in high tempreture and is pathogenic?

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over 3 years ago

asbfbhl;HWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBWGBO

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over 3 years ago

jem! if bactaria dont hv mitochordia

so how itdoes

glycolsis?

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almost 4 years ago

save it to my e-mail

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about 3 years ago

all neccesary information and clear examples have been provided on this web page.great effort.

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almost 4 years ago

heyyyyyyyyyyyy ahm ahm ahm, i like this website.....that is all

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over 5 years ago

I agree! The electron transport chain in bacteria and other prokaryotes is included within the membrane, while glycolysis and the citric acid cycle occur in the cytoplasm.

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over 2 years ago

BACTERIA

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almost 3 years ago

Other Free Encyclopedias » Science Encyclopedia » Science & Philosophy: A-series and B-series to Ballistic Missiles - Categories Of Ballistic Missile
Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria

cell temperature carbon oxygen temperatures organisms nitrogen water
Ads by Google
Stem Cell Research Videos
Ever wanted to see real stem cell
research? Watch now at JoVE
www.JoVE.com
Bacteria culture media
Commonly used growth media LB, TB..
Special media support OD600=30 - 50
www.exptec.com
PeproTech EC Ltd
Cytokines, Chemokines, Interleukins
Antibodies, ELISA Kits
www.peprotechec.com
Future Generation Energy
Bringing 24hr Solar Thermal Power
Generation for a better tomorrow
www.konicaminolta.com
Related Articles

Comparisons of in vitro nitrate reduction, methanogenesis, and fermentation acid profile among rumen bacterial, protozoal and fungal fractions.
INTRODUCTION The main sources of nitrate intake by ruminants are feeds and water. Nitrate in forage has been reported to make up about 37% of total nitrogen (Miyazaki, 1977), especially in green
Recycling of fermented sawdust-based oyster mushroom spent substrate as a feed supplement for postweaning calves.
INTRODUCTION Worldwide cultivation of Pleurotus spp. has greatly increased during the previous few decades (Chang, 1999; Royse, 2002). In Korea, total mushroom production was 158,642 M/T in 2008 of
Cassava in lactating sow diets: I. Effects on milk composition and quality.
INTRODUCTION Cassava root meal (Manihot esculent, Crantz.) is a low-cost basal feed ingredient in the tropics. It has a number of advantages for animal feeding including a high content of soft starch
Concert honors cancer survivors
GURNEE — Sixteen-year cancer survivor and local resident Mary Lou Falk was among more than 1,000 attendees at the 11th annual Concert for Life event held at St. Paul the Apostle Church. She said the

Listen to an audio version of this article.

Bacteria are mostly unicellular organisms that lack chlorophyll and are among the smallest living things on earth—only viruses are smaller. Multiplying rapidly under favorable conditions, bacteria can aggregate into colonies of millions or even billions of organisms within a space as small as a drop of water.

The Dutch merchant and amateur scientist Anton van Leeuwenhoek was the first to observe bacteria and other microorganisms. Using single-lens microscopes of his own design, he described bacteria and other microorganisms (calling them "animacules") in a series of letters to the Royal Society of London between 1674 and 1723.

Bacteria are classified as prokaryotes. Broadly, this taxonomic ranking reflects the fact that the genetic material of bacteria is contained in a single, circular chain of deoxyribonucleic acid (DNA) that is not enclosed within a nuclear membrane. The word prokaryote is derived from Greek meaning "prenucleus." Moreover, the DNA of prokaryotes is not associated with the special chromosome proteins called histones, which are found in higher organisms. In addition, prokaryotic cells lack other membrane-bounded organelles, such as mitochondria. Prokaryotes belong to the kingdom Monera. Some scientists have proposed splitting this designation into the kingdoms Eubacteria and Archaebacteria. Eubacteria, or true bacteria, consist of more common species, while Archaebacteria (with the prefix archae—meaning ancient) represent strange bacteria that inhabit very hostile environments. Scientists believe these bacteria are most closely related to the bacteria which lived when the earth was very young. Examples of archaebacteria are those bacteria which currently live in extremely salty environments or extremely hot environments, like geothermal vents of the ocean floor.
Stages of bacterial growth

Under ideal conditions, the growth of a population of bacteria occurs in several stages termed lag, log, stationary, and death.

During the lag phase, active metabolic activity occurs involving synthesis of DNA and enzymes, but no growth. Geometric population growth occurs during the log, or exponential phase, when metabolic activity is most intense and cell reproduction exceeds cell death. Following the log phase, the growth rate slows and the production of new cells equals the rate of cell death. This period, known as the stationary phase, involves the establishment of an equilibrium in population numbers and a slowing of the metabolic activities of individual cells. The stationary phase reflects a change in growing condition—for example, a lack of nutrients and/or the accumulation of waste products.

When the rate of cell deaths exceeds the number of new cells formed, the population equilibrium shifts to a net reduction in numbers and the population enters the death phase, or logarithmic decline phase. The population may diminish until only a few cells remain, or the population may die out entirely.

Temperature and bacteria

The lowest temperature at which a particular species will grow is the minimum growth temperature, while the maximum growth temperature is the highest temperature at which they will grow. The temperature at which their growth is optimal is called the optimum growth temperature. In general, the maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart.

Most bacteria thrive at temperatures at or around that of the human body 98.6°F (37°C), and some, such as Escherichia coli, are normal parts of the human intestinal flora. These organisms are mesophiles (moderate-temperature-loving), with an optimum growth temperature between 77°F (25°C) and 104°F (40°C). Mesophiles have adapted to thrive in temperatures close to that of their host.

Psychrophiles, which prefer cold temperatures, are divided into two groups. One group has an optimal growth temperature of about 59°F (15°C), but can grow at temperatures as low as 32°F (0°C). These organisms live in ocean depths or Arctic regions. Other psychrophiles that can also grow at 32°F (0°C) have an optimal growth temperature between 68°F (20°C) and 86°F (30°C). These organisms, sometimes called psychrotrophs, are often those associated with food spoilage under refrigeration.

Thermophiles thrive in very hot environments, many having an optimum growth temperature between 122°F (50°C) and 140°F (60°C), similar to that of hot springs in Yellowstone National Park. Such organisms thrive in compost piles, where temperatures can rise as high as 140°F (60°C). Extreme thermophiles grow at temperatures above 195°F (91°C). Along the sides of hydrothermal vents on the ocean bottom 217 mi (350 km) north of the Galapagos Islands, for example, bacteria grow in temperatures that can reach 662°F (350°C).

pH and bacteria

Like temperature, pH also plays a role in determining the ability of bacteria to grow or thrive in particular environments. Most commonly, bacteria grow optimally within a narrow range of pH between 6.7 and 7.5.

Acidophiles, however, prefer acidic conditions. For example, Thiobacillus ferrooxidans, which occurs in drainage water from coal mines, can survive at pH 1. Other bacteria, such as Vibrio cholera, the cause of cholera, can thrive at a pH as high as 9.0.


about 1 year ago

Clint

Um, when did we as humans ever have chloroplasts Oliver? Unless you meant algae and plant cells, then I'd totally agree.


about 1 year ago

Oliver

Mitochondrion and Chloroplasts were believed to be free-living organisms such as Bacteria.

Perhaps photosynthetic bacteria became the chloroplasts found in our cells...


9 months ago

hryt

yjtjjjjjjbhbtyhbbbbbfjhlhdfgjshdfkjghauro;ajshsguayrouihoriuhijkrkgggrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr


4 months ago

maurinesolayao

Although all bacteria share certain structural, genetic, and metabolic characteristics, important biochemical differences exist among the many species of bacteria. These differences permit bacteria to live in many different, and sometimes extreme, environments. For example, some bacteria recycle nitrogen and carbon from decaying organic matter, then release these gases into the atmosphere to be re…

Read more: Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria http://science.jrank.org/pages/714/Bacteria.html#ixzz1RPKY581V


6 months ago

mostafa

what bacteria(3 cases) growth in high tempreture and is pathogenic?


about 1 year ago

Ryan

Jen and fudgie7062 are correct. Bacteria are prokaryotes; therefore, they lack a nucleus and ALL membrane-bound organelles (including mitochondria). Having membrane-bound organelles is one of the major and basic distinctions between prokaryotic and eukaryotic cells.


6 months ago

jwlandhar

ilike this page


10 months ago

sanaullah

jem! if bactaria dont hv mitochordia

so how itdoes

glycolsis?



11 months ago

sara

save it to my e-mail


about 1 year ago

Richard Grant

Error: In text it says "maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart." This should read "..30°F (17°C) apart"





almost 3 years ago

Jen

Umm...why is this article discussing mitochondria under the Aerobic Bacteria subheading???

Bacteria don't have mitochondria!!!!


over 2 years ago

fudgie7062

I agree! The electron transport chain in bacteria and other prokaryotes is included within the membrane, while glycolysis and the citric acid cycle occur in the cytoplasm.



Read more: Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria - JRank Articles http://science.jrank.org/pages/714/Bacteria.html#ixzz1DnIupe2C

Vote down Vote up

almost 3 years ago

Other Free Encyclopedias » Science Encyclopedia » Science & Philosophy: A-series and B-series to Ballistic Missiles - Categories Of Ballistic Missile
Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria

cell temperature carbon oxygen temperatures organisms nitrogen water
Ads by Google
Stem Cell Research Videos
Ever wanted to see real stem cell
research? Watch now at JoVE
www.JoVE.com
Bacteria culture media
Commonly used growth media LB, TB..
Special media support OD600=30 - 50
www.exptec.com
PeproTech EC Ltd
Cytokines, Chemokines, Interleukins
Antibodies, ELISA Kits
www.peprotechec.com
Future Generation Energy
Bringing 24hr Solar Thermal Power
Generation for a better tomorrow
www.konicaminolta.com
Related Articles

Comparisons of in vitro nitrate reduction, methanogenesis, and fermentation acid profile among rumen bacterial, protozoal and fungal fractions.
INTRODUCTION The main sources of nitrate intake by ruminants are feeds and water. Nitrate in forage has been reported to make up about 37% of total nitrogen (Miyazaki, 1977), especially in green
Recycling of fermented sawdust-based oyster mushroom spent substrate as a feed supplement for postweaning calves.
INTRODUCTION Worldwide cultivation of Pleurotus spp. has greatly increased during the previous few decades (Chang, 1999; Royse, 2002). In Korea, total mushroom production was 158,642 M/T in 2008 of
Cassava in lactating sow diets: I. Effects on milk composition and quality.
INTRODUCTION Cassava root meal (Manihot esculent, Crantz.) is a low-cost basal feed ingredient in the tropics. It has a number of advantages for animal feeding including a high content of soft starch
Concert honors cancer survivors
GURNEE — Sixteen-year cancer survivor and local resident Mary Lou Falk was among more than 1,000 attendees at the 11th annual Concert for Life event held at St. Paul the Apostle Church. She said the

Listen to an audio version of this article.

Bacteria are mostly unicellular organisms that lack chlorophyll and are among the smallest living things on earth—only viruses are smaller. Multiplying rapidly under favorable conditions, bacteria can aggregate into colonies of millions or even billions of organisms within a space as small as a drop of water.

The Dutch merchant and amateur scientist Anton van Leeuwenhoek was the first to observe bacteria and other microorganisms. Using single-lens microscopes of his own design, he described bacteria and other microorganisms (calling them "animacules") in a series of letters to the Royal Society of London between 1674 and 1723.

Bacteria are classified as prokaryotes. Broadly, this taxonomic ranking reflects the fact that the genetic material of bacteria is contained in a single, circular chain of deoxyribonucleic acid (DNA) that is not enclosed within a nuclear membrane. The word prokaryote is derived from Greek meaning "prenucleus." Moreover, the DNA of prokaryotes is not associated with the special chromosome proteins called histones, which are found in higher organisms. In addition, prokaryotic cells lack other membrane-bounded organelles, such as mitochondria. Prokaryotes belong to the kingdom Monera. Some scientists have proposed splitting this designation into the kingdoms Eubacteria and Archaebacteria. Eubacteria, or true bacteria, consist of more common species, while Archaebacteria (with the prefix archae—meaning ancient) represent strange bacteria that inhabit very hostile environments. Scientists believe these bacteria are most closely related to the bacteria which lived when the earth was very young. Examples of archaebacteria are those bacteria which currently live in extremely salty environments or extremely hot environments, like geothermal vents of the ocean floor.
Stages of bacterial growth

Under ideal conditions, the growth of a population of bacteria occurs in several stages termed lag, log, stationary, and death.

During the lag phase, active metabolic activity occurs involving synthesis of DNA and enzymes, but no growth. Geometric population growth occurs during the log, or exponential phase, when metabolic activity is most intense and cell reproduction exceeds cell death. Following the log phase, the growth rate slows and the production of new cells equals the rate of cell death. This period, known as the stationary phase, involves the establishment of an equilibrium in population numbers and a slowing of the metabolic activities of individual cells. The stationary phase reflects a change in growing condition—for example, a lack of nutrients and/or the accumulation of waste products.

When the rate of cell deaths exceeds the number of new cells formed, the population equilibrium shifts to a net reduction in numbers and the population enters the death phase, or logarithmic decline phase. The population may diminish until only a few cells remain, or the population may die out entirely.

Temperature and bacteria

The lowest temperature at which a particular species will grow is the minimum growth temperature, while the maximum growth temperature is the highest temperature at which they will grow. The temperature at which their growth is optimal is called the optimum growth temperature. In general, the maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart.

Most bacteria thrive at temperatures at or around that of the human body 98.6°F (37°C), and some, such as Escherichia coli, are normal parts of the human intestinal flora. These organisms are mesophiles (moderate-temperature-loving), with an optimum growth temperature between 77°F (25°C) and 104°F (40°C). Mesophiles have adapted to thrive in temperatures close to that of their host.

Psychrophiles, which prefer cold temperatures, are divided into two groups. One group has an optimal growth temperature of about 59°F (15°C), but can grow at temperatures as low as 32°F (0°C). These organisms live in ocean depths or Arctic regions. Other psychrophiles that can also grow at 32°F (0°C) have an optimal growth temperature between 68°F (20°C) and 86°F (30°C). These organisms, sometimes called psychrotrophs, are often those associated with food spoilage under refrigeration.

Thermophiles thrive in very hot environments, many having an optimum growth temperature between 122°F (50°C) and 140°F (60°C), similar to that of hot springs in Yellowstone National Park. Such organisms thrive in compost piles, where temperatures can rise as high as 140°F (60°C). Extreme thermophiles grow at temperatures above 195°F (91°C). Along the sides of hydrothermal vents on the ocean bottom 217 mi (350 km) north of the Galapagos Islands, for example, bacteria grow in temperatures that can reach 662°F (350°C).

pH and bacteria

Like temperature, pH also plays a role in determining the ability of bacteria to grow or thrive in particular environments. Most commonly, bacteria grow optimally within a narrow range of pH between 6.7 and 7.5.

Acidophiles, however, prefer acidic conditions. For example, Thiobacillus ferrooxidans, which occurs in drainage water from coal mines, can survive at pH 1. Other bacteria, such as Vibrio cholera, the cause of cholera, can thrive at a pH as high as 9.0.


about 1 year ago

Clint

Um, when did we as humans ever have chloroplasts Oliver? Unless you meant algae and plant cells, then I'd totally agree.


about 1 year ago

Oliver

Mitochondrion and Chloroplasts were believed to be free-living organisms such as Bacteria.

Perhaps photosynthetic bacteria became the chloroplasts found in our cells...


9 months ago

hryt

yjtjjjjjjbhbtyhbbbbbfjhlhdfgjshdfkjghauro;ajshsguayrouihoriuhijkrkgggrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr


4 months ago

maurinesolayao

Although all bacteria share certain structural, genetic, and metabolic characteristics, important biochemical differences exist among the many species of bacteria. These differences permit bacteria to live in many different, and sometimes extreme, environments. For example, some bacteria recycle nitrogen and carbon from decaying organic matter, then release these gases into the atmosphere to be re…

Read more: Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria http://science.jrank.org/pages/714/Bacteria.html#ixzz1RPKY581V


6 months ago

mostafa

what bacteria(3 cases) growth in high tempreture and is pathogenic?


about 1 year ago

Ryan

Jen and fudgie7062 are correct. Bacteria are prokaryotes; therefore, they lack a nucleus and ALL membrane-bound organelles (including mitochondria). Having membrane-bound organelles is one of the major and basic distinctions between prokaryotic and eukaryotic cells.


6 months ago

jwlandhar

ilike this page


10 months ago

sanaullah

jem! if bactaria dont hv mitochordia

so how itdoes

glycolsis?



11 months ago

sara

save it to my e-mail


about 1 year ago

Richard Grant

Error: In text it says "maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart." This should read "..30°F (17°C) apart"





almost 3 years ago

Jen

Umm...why is this article discussing mitochondria under the Aerobic Bacteria subheading???

Bacteria don't have mitochondria!!!!


over 2 years ago

fudgie7062

I agree! The electron transport chain in bacteria and other prokaryotes is included within the membrane, while glycolysis and the citric acid cycle occur in the cytoplasm.



Read more: Bacteria - Characteristics Of Bacteria, Bacterial Growth, Physical And Chemical Requirements For Bacterial Growth, The Role Of Bacteria In Fermentation - Aerobic and anaerobic bacteria - JRank Articles http://science.jrank.org/pages/714/Bacteria.html#ixzz1DnIupe2C

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over 3 years ago

Excellent overview on bacteria. Very helpful! Thank you for all your time and hard work. : )

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over 3 years ago

normal

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almost 4 years ago

save it to my e-mail

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almost 2 years ago

bacteria need ideal conditions like good nutrients the right temp and right food sources and not to high of acidity



















































































































































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ha.

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about 2 years ago

Dear Sir,
I would kike to know the quantities calculation of Urea & DAP as a food to aerobic bacterias.

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about 2 years ago

The contents are very educational and informative. As a first year trainee in pathology, they are very clear and easy to understand and remember for future reference in microbiology.

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over 2 years ago

PSEUDOMONAS is actually an obligate aerobe with the ability to utilize nitrate as an alternative terminal electron acceptor.

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over 2 years ago

Why don't micro-organisms like to function when moisture levels are too high?

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over 2 years ago

Aerobic bacteria section... check it well there is a mistake.. they have no mitochondria.

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over 2 years ago

ghththtteteerwergertgerterter

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almost 3 years ago

Please send me information on the following: Characteristics of a) bacteria, b) fungi, and c) virus.

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almost 3 years ago

Bacteria!!

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about 3 years ago

Addie it is not a mitochondria that is inside of bacteria it is a membrane bound organelle and therfore not in bacteria

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almost 4 years ago

save it to my e-mail

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almost 4 years ago

So like ya its me again. What does space and water have to do with all this. Hastaluego. Btw means c u l8r in espanoul/spanish.