Industrial fermentation
2723752
213859216
2008-05-21T02:28:28Z
Elkman
346341
dablink, Replaced: [[Fats]] → [[fat]]s using [[Project:AutoWikiBrowser|AWB]]
{{otheruses4|industrial fermentation|other types of fermentation|fermentation}}
Fermentation has many important uses in industry. Though the word ''fermentation'' can have stricter definitions, when speaking of it in '''industrial fermentation''' it more loosely refers to the breakdown of organic substances and re-assembly into other substances. Somewhat paradoxically, fermenter culture in industrial capacity often refers to highly oxygenated and aerobic growth conditions, whereas [[fermentation (biochemistry)|fermentation]] in the biochemical context is a strictly anaerobic process. A very old method is [[ABE fermentation]].
== Food fermentation ==
{{main|Fermentation (food)}}
Ancient fermented food processes, such as making [[bread]], [[wine]], [[cheese]], [[curds]], [[idli]], [[dosa]], etc., can be dated to more than [[5th millennium BC|6,000 yr ago]]. They were developed long before man had any knowledge of the existence of the [[microorganism]]s involved. Also, fermentation is a powerful economic incentive for semi-industrialized countries, in their willingness to produce [[bio-ethanol]]. <!-- bio-diesel does involve fermentation, but transesterification //-->
== Pharmaceuticals and the biotechnology industry==
There are 5 major groups of commercially important fermentation:
# [[Microbial]] [[cell (biology)|cell]]s or [[biomass]] as the product, e.g. [[bakers yeast]], [[lactobacillus]], etc.
# Microbial [[enzyme]]s: [[catalase]], [[amylase]], [[protease]], [[pectinase]], [[glucose isomerase]], [[cellulase]], [[hemicellulase]], [[lipase]], [[lactase]], [[streptokinase]], etc.
# Microbial [[metabolite]]s :
## Primary metabolites – [[ethanol]], [[citric acid]], [[glutamic acid]], [[lysine]], [[vitamin]]s, [[polysaccharide]]s etc.
## Secondary metabolites: all [[antibiotic]] fermentation
# Recombinant products: [[insulin]], [[HBV]], [[interferon]], [[GCSF]], [[streptokinase]]
# Biotransformations: [[phenyl acetyl carbinol]], [[steroid]] [[biotransformation]], etc.
=== Nutrient sources for industrial fermentation===
Growth media are required for industrial fermentation, since any microbe requires water, oxygen, an energy source, a carbon source, a nitrogen source and micronutrients for growth.
Carbon & energy source + nitrogen source + O<sub>2</sub> + other requirements → Biomass + Product + byproducts + CO<sub>2</sub> + H<sub>2</sub>O + heat
{|class="wikitable" style="text-align:center"
!Nutrient||Raw material
|-
|colspan=2|'''Carbon'''
|-
|[[Glucose]]||corn sugar, [[starch]], [[cellulose]]
|-
|[[Sucrose]]||[[sugarcane]], [[sugar beet]] [[molasses]]
|-
|[[Lactose]]||milk [[whey]]
|-
|[[fat]]s||[[vegetable oil]]s
|-
|[[Hydrocarbons]]||[[petroleum]] fractions
|-
|colspan=2|'''Nitrogen'''
|-
|[[Protein]]||[[soybean]] meal, cornsteep liquor, distillers' solubles
|-
|[[Ammonia]]||pure ammonia or ammonium salts<br>urea
|-
|[[Nitrate]]||nitrate salts
|-
|Phosphorus source||phosphate salts
|-
|colspan=2|'''Vitamins and growth factors'''
|-
| ||Yeast extract
|-
| ||Beef extract
|-
| ||Corn steep liquor
|-
|-
|}
[[Trace element]]s: Fe, Zn, Cu, Mn, Mo, Co
[[Antifoaming agent]]s :
Esters, fatty acids, fats, silicones, sulphonates, polypropylene
[[Buffer]]s: Calcium carbonate, phosphates
[[Growth factor]]s:
Some microorganisms cannot synthesize the required cell components themselves and need to be supplemented, e.g. with [[thiamine]], [[biotin]], [[calcium pentothenate]]
[[Precursor]]s:
Directly incorporated into the desired product: Phenyl ethylamine into Benzyl penicillin, Phenyl acetic acid into Penicillin G
[[Inhibitor]]s:
To get the specific products: e.g. sodium [[barbital]] for [[rifamycin]]
[[Inducer]]s:
The majority of the enzymes used in industrial fermentation are inducible and are synthesized in response of inducers: e.g. starch for amylases, maltose for pollulanase, pectin for pectinase,olive oil and tween are also used at times.
[[Chelator]]s:
Chelators are the chemicals used to avoid the precipitation of metal ions. Chelators like [[EDTA]], [[citric acid]], [[polyphosphate]]s are used in low concentrations.
==Sewage disposal==
{{main|Sewage disposal}}
In the process of sewage disposal, sewage is digested by enzymes secreted by bacteria.
Solid organic matters are broken down into harmless, soluble substances and carbon dioxide.
Liquids that result are disinfected to remove pathogens before being discharged into rivers or the sea or can be used as liquid fertilisers.
Digested solids, known also as sludge, is dried and used as fertilisers.
Gaseous by-products such as methane, can be utilised as biogas to fuel generators.
One advantage of bacterial digestion is that it reduces the bulk and odour of sewage, thus reducing space needed for dumping, on the other hand, a major disadvantage of bacterial digestion in sewage disposal is that it is a very slow process.
===Phases of microbial growth===
When a particular organism is introduced into a selected growth medium, the medium is inoculated with the particular organism. Growth of the inoculum does not occur immediately, but takes a little while. This is the period of adaptation, called the lag phase.
Following the lag phase, the rate of growth of the organism steadily increases, for a certain period--this period is the log or exponential phase.
After a certain time of exponential phase, the rate of growth slows down, due to the continuously falling concentrations of nutrients and/or a continuously increasing (accumulating) concentrations of toxic substances. This phase, where the increase of the rate of growth is checked, is the deceleration phase.
After the deceleration phase, growth ceases and the culture enters a stationary phase or a steady state. The biomass remains constant, except when certain accumulated chemicals in the culture lyse the cells (chemolysis). Unless other micro-organisms contaminate the culture, the chemical constitution remains unchanged. Mutation of the organism in the culture can also be a source of contamination, called internal contamination.
== See also ==
* [[Fed-batch]]
* [[Chemostat]]
* [[Industrial microbiology]]
* [[Food microbiology]]
==External links==
=== Related journals ===
*[http://www.tandf.co.uk/journals/titles/08905436.asp ''Food Biotechnology'']
*[http://www3.interscience.wiley.com/cgi-bin/jhome/71002188?CRETRY=1&SRETRY=0 ''Biotechnology and Bioengineering'']
*[http://www.journalarchive.jst.go.jp/english/jnltop_en.php?cdjournal=jbb1977 ''Journal of Fermentation Technology'']
==References==
* Schutyser, M.A.I., 2003, [http://library.wur.nl/wda/dissertations/dis3411.pdf Solid state fermentation], PhD Thesis, Wageningen UR
* Biochemical Engineering Fundamentals by J.E. Bailey and P.F. Ollis, McGraw Hill Publication
* Principles of fermentation technology by Stansbury, P.F., A. Whitaker and S.J. Hall, 1997
[[Category:Fermentation]]
[[Category:Microbiology techniques]]
[[Category:Biotechnology]]
[[Category:Pharmaceutical industry]]
[[Category:Waste treatment technology]]
[[Category:Industrial processes]]