Industrial microbiology

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Industrial microbiology is a branch of biotechnology that applies microbial sciences to create industrial products in mass quantities. There are multiple ways to manipulate a microorganism in order to increase maximum product yields. Introduction of mutations into an organism may be accomplished by introducing them to mutagens. Another way to increase production is by gene amplification, this is done by the use of plasmids, and vectors. The plasmids and/ or vectors are used to incorporate multiple copies of a specific gene that would allow more enzymes to be produced that eventually cause more product yield.[1] The manipulation of organisms in order to yield a specific product has many applications to the real world like the production of some antibiotics, vitamins, enzymes, amino acids, solvents, alcohol and daily products. They can also be used in an agricultural application and use them as a biopesticede instead of using dangerous chemicals or as inoculants and help plant proliferation.

Medical application[edit]

Representation of bioreactors. They are used to store the microbes while they are producing desired product of interest.

The medical application to industrial microbiology is the production of new drugs synthesized in a specific organism for medical purposes. Production of antibiotics is necessary for the treatment of many bacterial infections.Some natural occurring antibiotics and precursors, are produced through a process called fermentation. The microorganisms grow in a liquid media where the population size is controlled in order to yield the greatest amount of product. In this environment nutrient, pH, temperature, and oxygen are controlled also in order to maximize the amount of cells and cause them not to die before the production of the antibiotic of interest. Once the antibiotic is produced it must be extracted in order to yield an income.

Vitamins also get produced in massive quantities either by fermentation or biotransformation.[2] Vitamin B 2 (riboflavin) for example is produced both ways. Biotransformation is mostly used for the production of riboflavin, and the carbon source starting material for this reaction is glucose. There are a few strains of microorganisms that were engineered to increase the yield of riboflavin produced. The most common organism used for this reaction is Ashbya gossypii. The fermentation process is another common way to produce riboflavin. The most common organism used for production of riboflavin through fermentation is Eremothecium ashbyii. Once riboflavin is produced it must be extracted from the broth, this is done by heating the cells for a certain amount of time, and then the cells can be filtered out of solution. Riboflavin is later purified and released as final product.[3]

Enzymes can be produced through fermentation either by submerged fermentation and/ or by solid state fermentation.[4] Submerged fermentation is referred to when the microorganisms are in contact with media. In this process the contact with oxygen is essential. The bioreactors/fermentors that are used to do these mass production of product can store up to 500 cubic meters in volume. Solid state fermentation is less common than submerged fermentation, but has many benefits. There is less need for the environment to be sterile since there is less water, there is a higher stability and concentration for the end product.[4] Insulin synthesis is done through the fermentation process and the use of recombinant E.coli or yeast in order to make human insulin also called Humulin.

Food industry application[edit]


_Fermentation is a reaction where sugar can be converted into a gas, alcohols or acids. _Microorganisms like yeast and bacteria are used to massively produce the many things. Drinking alcohol also known as ethanol is produced by yeast and bacteria. _Ethanol can also be used as a fuel source. _The drinking alcohol is produced from natural sugars like glucose. _Carbon dioxide is produced as a side product in this reaction and can be used to make bread, and can also be used to carbonate beverages. FermentationWine : _Alcoholic beverages like beer and wine are fermented by microorganisms when there is no oxygen present.

In this process, once there is enough alcohol and carbon dioxide around in the media the yeast start to die due to the environment becoming toxic to them. There are many strains of yeast and bacteria that can tolerate different amounts of alcohol around in their environment before it becoming toxic, thus one can obtain different alcohol levels in beer and wine, just by selecting a different microbial strain.

_Most yeast can tolerate between 10 and 15 percent alcohol, but there are some strains that can tolerate up to 21 percent alcohol. _Dairy products like cheese and yogurt can also be made through fermentation using microbes. Cheese was produced as a way to preserve the nutrients obtained from milk, through

fermentation thus elongating the shelf-life of the product. _Microbes are used to convert the lactose sugars into lactic acid through fermentation. _The bacteria used for such fermentation are usually from Lactococci, Lactobacilli, or Streptococci families. _Sometimes these microbes are added before or after the acidification step needed for cheese production. _Also these microbes are responsible for the different flavors of cheese, since they have enzymes that breakdown milk sugars and fats into multiple building blocks.

_Some other microbes like mold may be purposely introduced during or before the aging of the cheese, in order to give it a different flavor.

_The production of yogurt starts from the pasteurization of milk, where undesired microbes are reduced or eliminated. _Once the milk is pasteurized the milk is ready to be processed to reduce fat and liquid content, so what remains is mostly solid content. _This can be done by drying the milk so that the liquid evaporates or by adding concentrated milk. _Increasing the solid content of the milk also increases the nutritional value since the nutrients are more concentrated. _After this step is accomplished, the milk is ready for fermentation where the milk gets inoculated with bacteria in hygienic stainless steel containers and then gets carefully monitored for lactic acid production, temperature and pH.

Agriculture application[edit]

Biopesticide is a pesticide derivatized from a living organism or natural occurring substances. Biochemical pesticides can also be produced from naturally occurring substances that can control pest populations in a non-toxic matter.[5] An example of a biochemical pesticide is garlic and pepper based insecticides, these work by repelling insects from the desired location. Microbial pesticides, usually a virus, bacterium, or fungus are used to control pest populations in a more specific manner.[5] The most commonly used microbe for the production of microbial bio-pesticides is Bacillus thuringiensis, also known as Bt. This spore forming bacterium produces a delta-endotoxins in which it causes the insect or pest to stop feeding on the crop or plant because the endotoxin destroys the lining of the digestive system. Another mechanism that is used to reduce plant pathogens is by introducing other microbes that are non-pathogenic but compete for the rhizosphere, and succeed by producing anti fungal chemicals yielding plant growth.[6]

Microbial inoculants are addition of microbes into a plant that would essentially help the plant grow by introducing nutrients, and stimulating plant growth. The preparation in mass quantities of any inoculum is performed by a process called fermentation. The first step to making it is by selecting a microbial strain, and letting it grow and increase in bacterial concentration. The greater the bacterial concentration the greater the fermentation yield would be (fermentation yield is ratio of bacterial concentration to mass of substrate)[7] The bacterial concentration can be measured by monitoring the turbidity, wet or dry weight, or residual nutrient concentration. After the inoculant is ready then it gets transferred in a fermentor where oxygen and temperature most be highly monitored for the survival of the microbes and it can vary depending on the microbe that is being used. After enough time has passed for the microbes to be properly incubated the product is ready to be extracted purified and packaged.[7]

Chemical application[edit]

Synthesis of amino acids and organic solvents can also be made using microbes. The synthesis of essential amino acids such as are L-Methionine, L-Lysine, L-Tryptophan and the non-essential amino acid L-Glutamic acid are used today mainly for feed, food, and pharmaceutical industries. The production of these amino acids is due to Corynebacterium glutamicum and fermentation. C.glutamicum was engineered to be able to produce L-lysine and L-Glutamic acid is large quantities.[8] L-Glutamic acid had a high demand for production because this amino acid is used to produce Monosodium glutamate (MSG) a food flavoring agent. In 2012 the total production of L-Glutamic acid was 2.2 million tons and is produced using a submerged fermentation technique inoculated with C.glutamicum. L-Lysine was originally produced from diaminopimelic acid (DAP) by E.coli, but once the C.glutamicum was discovered for the production of L-Glutamic acid.[8] This organism and other autotrophs were later modified to yield other amino acids such as lysine, aspartate, methionine, isoleucine and threonine.[8] L-Lysine is used for the feeding of pigs and chicken, as well as to treat nutrient deficiency, increase energy in a patient, and sometimes used to treat viral infections. L-Tryptophan is also produced through fermentation and by Corynebacterium and E.coli, though the production is not as large as the rest of the amino acids it is still produced for pharmaceutical purposes since it can be converted and used to produce neurotransmitters.[8]

The production of organic solvents like acetone, butanol, and isopropanol through fermentation was one of the very first things to be produced by using bacteria, since achieving the necessary chirality of the products is easily achieved by using living systems.[9] Solvent fermentation uses a series of Clostridia bacterial species. Solvent fermentation at first was not as productive as it is used today. The amount of bacteria required to yield a product was high, and the actual yield of product was low. Later technological advances were discovered that allowed scientist to genetically alter these strains to achieve a higher yield for these solvents. These Clostridial strains were transformed to have extra gene copies of enzymes necessary for solvent production, as well as being more tolerant to higher concentrations of the solvent being produced, since these bacteria have a range of product in which they can survive in before the environment becomes toxic.[10] Yielding more strains that can use other subtrates was also another way to increase the productivity of these bacteria.[10]


  1. ^ Boundless (2016-05-26). "Industrial Production of Antibiotics". Boundless.
  2. ^ Vandamme, E. J. (1992-01-01). "Production of vitamins, coenzymes and related biochemicals by biotechnological processes". Journal of Chemical Technology and Biotechnology (Oxford, Oxfordshire: 1986). 53 (4): 313–327. ISSN 0268-2575. PMID 1368195.
  3. ^ "Microbial Production of Vitamins: An Overview". Biology Discussion. 2015-09-21. Retrieved 2017-02-23.
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  5. ^ a b EPA, OCSPP, OPP, US. "What are Biopesticides?". Retrieved 2017-03-12.
  6. ^ "Microbial Biopesticides: Bacteria | Biopesticide Industry Alliance". Retrieved 2017-03-13.
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  8. ^ a b c d "Microbial amino acids production (PDF Download Available)". ResearchGate. doi:10.13140/2.1.2822.2245.
  9. ^ Chen, Jiann-Shin; Zidwick, Mary Jo; Rogers∗, Palmer (2013-01-01). Rosenberg, Eugene; DeLong, Edward F.; Lory, Stephen; Stackebrandt, Erko; Thompson, Fabiano, eds. The Prokaryotes. Springer Berlin Heidelberg. pp. 77–134. doi:10.1007/978-3-642-31331-8_386. ISBN 9783642313301.
  10. ^ a b "The genetic engineering of microbial solvent production - ScienceDirect" (PDF). Retrieved 2017-03-17.