Bacterial cellulose carbon sources

Tarr and Hibbert13 published the first detailed study of the formation of bacterial cellulose. A systematic series of experiments, conducted with a view to obtaining a culture medium which did not support visible growth of A. xylinum until a suitable source of carbon was added, indicated that a solution (pH 5.0) containing 0.1% asparagine, 0.5% potassium dihydrogen phosphate, 0.1% sodium chloride and 0.5% ethanol satisfied these requirements. Maximum polysaccharide formation oc-... 

The metabolism of anaerobic chytrids has not been studied in great detail, but it is known that most anaerobic chytrids studied so far produce formate, acetate, succinate, lactate and ethanol besides hydrogen and carbon dioxide when growing on cellulose, glucose or fructose as a carbon source (Julliand et al. 1998). Such a mixed acid fermentation is very similar to bacterial mixed acid fermentations that are, for example, well known for facultative anaerobic enteric bacteria, such as Escherichia coli. 

The cell as a biosynthesis machine can use cheap carbon sources (waste products) as precursor substrates to produce bacterial polymers. However, the in vitro synthesis of biopolymers requires costly purified key enzymes and precursor molecules such as ATP, coal, coal bolsters, and nucleotide sugars or sugar acids to synthesize polymers such as PHA, cellulose, alginate, and PGA. Consequently, these polymers have limited commercial applicability due to their very high production costs. It is estimated the production of PHB by in vitro synthesis would amount to a cost of around US 286,000 per gram of PHB whereas, bacterial production of PHB was estimated to cost about 0.0025 per gram of PHB, and this is still 5-10 times as expensive to produce as the respective petroleum-based polymers. 

A. xylinum has been applied as model microorganism for basic and applied studies on cellulose. It is most commonly studied source of bacterial cellulose because of its ability to produce relatively high levels of polymer from a wide range of carbon and nitrogen sources [5]. 

The fermentation medium contains carbon, nitrogen and other macro- and micronutrients required for the growth of organism. Secretion of bacterial cellulose is usually most noticeable when the bacteria are supplied with an abundant carbon source and minimal nitrogen source [13]. Some authors uses a complex medium supplying amino acids and vitamins is also used to enhance the cell growth and production. 

F. Hong and K. Qiu. An alternative carbon source from konjac powder for enhancing production of bacterial cellulose in static cultures by a model strain Acetobacter aceti subsp. xylinus ATCC 23770. Carbohydr. Polym. 72, 545-549 (2008). 

Kurosumi, A., Sasaki, C., Yamashita, Y., Nakamura, Y., 2009. Utilization of various fruit juices as carbon source for production of bacterial cellulose by Acetobacter xylinum NBRC 13693. Carbohydrate Polymers 76 (2), 333—335. 

Additives could be used as cheap ways of increasing cellulose production. Together with appropriate carbon and nitrogen sources and culture conditions, combinations of additives may maximize bacterial cellulose production, and be useful for commercial applications. 

Mikkelsen D, Flanagan BM, Dykes GA, Gidley MJ (2009) Influence of different carbon sources on bacterial cellulose production by Gluconacetobacter xylinus strain ATCC 53524. J Appl Microbiol 107 576-583... 

The simplest alkane (that is, with n = 1) is methane CH4, which is a natural product of the anaerobic bacterial decomposition of vegetable matter under water. Because it was first collected in marshes, methane became known as marsh gas. A rather improbable but proven source of methane is termites. When these voracious insects consume wood, the microorganisms that inhabit their digestive system break down cellulose (the major component of wood) into methane, carbon dioxide, and other compounds. An estimated 170 million tons of methane are produced annually by termites It is also produced in some sewage treatment processes. Commercially,... 

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