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Category: Applied and Industrial Microbiology
Environmental Sustainability and Biotechnology, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555816094/9781555813048_Chap24-1.gif /docserver/preview/fulltext/10.1128/9781555816094/9781555813048_Chap24-2.gifAbstract:
The microbial metabolic pathway being exploited in food fermentation, then and now, is the glucose breakdown pathway. Yeasts break down the glucose in wheat flour to carbon dioxide, which causes bread to rise. If the starting material is fruit sugar, the product of glucose breakdown in yeast is wine. As with plant and animal agriculture, even though humans have always used microbial processes, the new biotechnologies, especially the bioprocess technologies and recombinant DNA technology, greatly expand the ways in which microbial processes contribute to human society. Life in unusual habitats makes for unique biocatalysts, and the great majority of that biochemical potential remains untapped. In the absence of bioprocess technologies that allow companies to manufacture a sufficient amount of product at an affordable price, the impact of recombinant DNA technology would be limited primarily to the research laboratory. The cost of converting cornstarch into sugar is one barrier to increasing the use of bioethanol. Genetically engineered microbes that decrease the cost of this step have been developed, but even so, in the absence of the government subsidies that are now provided for bioethanol, the cost of ethanol derived from cornstarch cannot compete with that of petroleum. The vast majority of bioremediation applications use naturally occurring microorganisms either to identify and filter manufacturing waste before it is introduced into the environment or to clean up existing pollution problems. Microbial catabolic pathways make it possible to use biomass as a raw material for generating biofuels and feedstock chemicals.
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Nature's technologies. The frog (Hyla ebraccata) (A) and bat (Thyropteratricolor) (B) have evolved similar adaptations for maintaining a fixed location. All tree frogs differ from most other frogs by having dilated toe tips that act as suction cups. Most bats hang by their sharp claws when they roost in caves or trees, but the disk-winged bat roosts inside a large tropical plant leaf as it unfurls. These bats use suction cups on their wrists and ankles to protect the fragile leaves.
Nature's technologies. The frog (Hyla ebraccata) (A) and bat (Thyropteratricolor) (B) have evolved similar adaptations for maintaining a fixed location. All tree frogs differ from most other frogs by having dilated toe tips that act as suction cups. Most bats hang by their sharp claws when they roost in caves or trees, but the disk-winged bat roosts inside a large tropical plant leaf as it unfurls. These bats use suction cups on their wrists and ankles to protect the fragile leaves.
Controlling production with feedback inhibition. Cells can control the amount of products (A and B) they make because one product (B) inhibits the binding of enzyme (E) to its substrate (S), which is the precursor of B.
Controlling production with feedback inhibition. Cells can control the amount of products (A and B) they make because one product (B) inhibits the binding of enzyme (E) to its substrate (S), which is the precursor of B.
Controlling production with gene regulation. (A) Bacteria manufacture the amino acid tryptophan when none is available from the environment. (B) When environmental concentrations of tryptophan are high, bacteria do not need to synthesize it. Under those conditions, the tryptophan-repressor protein complex binds to DNA and prevents the transcription of genes involved in tryptophan biosynthesis.
Controlling production with gene regulation. (A) Bacteria manufacture the amino acid tryptophan when none is available from the environment. (B) When environmental concentrations of tryptophan are high, bacteria do not need to synthesize it. Under those conditions, the tryptophan-repressor protein complex binds to DNA and prevents the transcription of genes involved in tryptophan biosynthesis.
Extremophiles. The red stream has high concentrations of sulfuric acid and iron, but the green photosynthetic microbes can tolerate these extreme conditions. (Photograph by D. E. White, courtesy of U.S. Geological Survey.)
Extremophiles. The red stream has high concentrations of sulfuric acid and iron, but the green photosynthetic microbes can tolerate these extreme conditions. (Photograph by D. E. White, courtesy of U.S. Geological Survey.)
Discovering extremophiles.(A) A researcher collects samples from a hot spring in the hope of finding microbes with genes that can degrade cellulose at very high temperatures. (B) Back in the laboratory, the microbes are cultured on media containing cellulose as the sole source of carbohydrates. Colonies that grow can degrade cellulose. (Photographs by Mike Himmel [A] and Warren Gretz [B], courtesy of the National Renewable Energy Laboratory.)
Discovering extremophiles.(A) A researcher collects samples from a hot spring in the hope of finding microbes with genes that can degrade cellulose at very high temperatures. (B) Back in the laboratory, the microbes are cultured on media containing cellulose as the sole source of carbohydrates. Colonies that grow can degrade cellulose. (Photographs by Mike Himmel [A] and Warren Gretz [B], courtesy of the National Renewable Energy Laboratory.)
Large-scale biomanufacturing. A large-scale biomanufacturing facility contains many bioreactors. (Image courtesy of the Evans U.S. Army Community Hospital.)
Large-scale biomanufacturing. A large-scale biomanufacturing facility contains many bioreactors. (Image courtesy of the Evans U.S. Army Community Hospital.)
Biomanufacturing. The nutrients contain the raw materials that the production cells will convert into products. The conversion of inputs into products occurs in a bioreactor, which comes equipped with sensors for monitoring the key environmental factors—temperature, oxygen level, and pH—so that the process can be adjusted to maintain optimal conditions for product manufacture. The outputs contain not only the commercial product, but also a waste stream that must be separated from the product stream.
Biomanufacturing. The nutrients contain the raw materials that the production cells will convert into products. The conversion of inputs into products occurs in a bioreactor, which comes equipped with sensors for monitoring the key environmental factors—temperature, oxygen level, and pH—so that the process can be adjusted to maintain optimal conditions for product manufacture. The outputs contain not only the commercial product, but also a waste stream that must be separated from the product stream.
Biomanufacturing of proteins. In the example shown, the company is using a bacterial host cell to manufacture human insulin. The gene encoding insulin must first be isolated and inserted into a plasmid. The plasmid carries the insulin gene into a bacterial host cell. The host cell is cloned to increase cell and plasmid numbers. The recombinant host cells grow and reproduce in a 1-liter flask. Eventually, the microbial population is so large it must be transferred to a 5-liter bioreactor. The next stage can be quite tricky as the manufacturing process is scaled up to thousands of liters. The insulin-manufacturing facility (not drawn to scale) contains many 10,000-liter bioreactors.
Biomanufacturing of proteins. In the example shown, the company is using a bacterial host cell to manufacture human insulin. The gene encoding insulin must first be isolated and inserted into a plasmid. The plasmid carries the insulin gene into a bacterial host cell. The host cell is cloned to increase cell and plasmid numbers. The recombinant host cells grow and reproduce in a 1-liter flask. Eventually, the microbial population is so large it must be transferred to a 5-liter bioreactor. The next stage can be quite tricky as the manufacturing process is scaled up to thousands of liters. The insulin-manufacturing facility (not drawn to scale) contains many 10,000-liter bioreactors.
Biofuels. The bus uses diesel fuel derived from soybean oil. (Photograph courtesy of the National Renewable Energy Laboratory and the Nebraska Soybean Board.)
Biofuels. The bus uses diesel fuel derived from soybean oil. (Photograph courtesy of the National Renewable Energy Laboratory and the Nebraska Soybean Board.)
From cornstarch to ethanol. The man is unloading corn at an ethanol plant. The starch in the corn will be broken down into corn sugar, which will be converted into ethanol. (Photograph by Warren Gertz, courtesy of the National Renewable Energy Laboratory.)
From cornstarch to ethanol. The man is unloading corn at an ethanol plant. The starch in the corn will be broken down into corn sugar, which will be converted into ethanol. (Photograph by Warren Gertz, courtesy of the National Renewable Energy Laboratory.)
Biodegradable plastics. A process developed at the Pacific Northwest National Laboratory converts the carbohydrates in potatoes into building block monomers that are used as feedstock chemicals in manufacturing plastics, adhesives, and textiles. (Photograph courtesy of the Pacific Northwest National Laboratory.)
Biodegradable plastics. A process developed at the Pacific Northwest National Laboratory converts the carbohydrates in potatoes into building block monomers that are used as feedstock chemicals in manufacturing plastics, adhesives, and textiles. (Photograph courtesy of the Pacific Northwest National Laboratory.)
Cellulosic biomass. Biofine Corporation in Waltham, Massachusetts, has developed a process that can convert cellulose into a small organic molecule that can serve as a monomer for synthesizing many chemicals. (Photograph courtesy of the Pacific Northwest National Laboratory.)
Cellulosic biomass. Biofine Corporation in Waltham, Massachusetts, has developed a process that can convert cellulose into a small organic molecule that can serve as a monomer for synthesizing many chemicals. (Photograph courtesy of the Pacific Northwest National Laboratory.)
A sewage treatment plant in Hawaii. (Photograph courtesy of the National Renewable Energy Laboratory.)
A sewage treatment plant in Hawaii. (Photograph courtesy of the National Renewable Energy Laboratory.)
Bioremediation of a gasoline spill. Gasoline from an underground storage tank seeps through the soil to the water table. After the leak is stopped, the free-floating gasoline is pumped out to a recovery tank. Polluted groundwater is pumped into a bioreactor tank with oxygen, nutrients, and hungry microbes. After the microbes eat the gasoline, the mixture of clean water, nutrients, and microbes is pumped back into the ground so that more of the pollutant can be degraded.
Bioremediation of a gasoline spill. Gasoline from an underground storage tank seeps through the soil to the water table. After the leak is stopped, the free-floating gasoline is pumped out to a recovery tank. Polluted groundwater is pumped into a bioreactor tank with oxygen, nutrients, and hungry microbes. After the microbes eat the gasoline, the mixture of clean water, nutrients, and microbes is pumped back into the ground so that more of the pollutant can be degraded.
Molecules produced by plants and used by people
Molecules produced by plants and used by people
Examples of the types and categories of microbial molecules that people and industries use
Examples of the types and categories of microbial molecules that people and industries use
Food fermentation and Products a
Microbes have been discovered living in extreme environments a
Microbes have been discovered living in extreme environments a
Environmental benefits of gasohol
Environmental benefits of gasohol