Glucose bacterial degradation

The enzyme systems needed for bacterial degradation of dibenzothiophene usually require an inducer which may be the substrate itself, naphthalene, anthracene or salicylate (59. 60). However, Pseudomonas sp. HL7b co-metabolizes dibenzothiophene constitutively (33). That is, a glucose-grown suspension of HL7b cells immediately started to oxidize dibenzothiophene when it was added to the medium and yielded HFBT among other metabolites. 

The galactose produced in this process is subsequently converted by the liver into additional glucose, which is then further metabolized to produce energy. Many people do not produce a sufficient amount of lactase and are incapable of hydrolyzing large quantities of lactose. Instead, lactose accumulates and is ultimately broken down into CO2 and H2 by bacteria present in the intestines. Bacterial degradation of lactose produces several by-products, including lactic acid. 

Two bacterial Shewanella species, S. putrefaciens and S. oneidensis, previously selected on the basis of their ability to degrade azo dyes, were also tested in saline medium at different salt concentrations of up to 10% to evaluate their potential to decolorize four structurally different azo dyes Reactive Black 5, Direct Red 81, Acid Red 88, and Disperse Orange 3. Full decolorization was reached at salt concentrations up to 6% the decolorization velocity was inversely related to salt concentration. The rate of decolorization was increased by yeast extract and a calcium source, while was decreased by glucose and by a nitrogen source [54]. 

The main product of anaerobic degradation of sugars by these organisms is lactic acid. Other products of bacterial carbohydrate metabolism include extracellular dextrans (see p. 40)—insoluble polymers of glucose that help bacteria to protect themselves from their environment. Bacteria and dextrans are components of dental plaque, which forms on inadequately cleaned teeth. When Ca salts and other minerals are deposited in plaque as well, tartar is formed. 

Complementary to hydrolysis by lysozyme189, an endo-acting N-acetyl-/ -D-glucosaminidase190-192 degrades bacterial cell-wall peptidoglycan to the disaccharide N-acetyl-/J-muramoyl-( 1 - 4)-2-acetamido-2-deoxy-D-glucose. 

They are prepared by enz3miatic degradation of starch. The enzyme cyclodextrin glucanosyltransferase (CGT) from Bacillus macerans. Bacillus megaterium or other bacterial strains cut the starch helix and join both ends of such destruct forming a cyclic compound. Because enzymes are not very specific, the obtained mixture contains cyclodextrins from 6 to 12 glucose units. The main fi-actions are a-, p- and y-cyclodextrins which correspond to 6, 7 and 8 glucose units. 

Los ses ff dissolyed humic substances from the water column occur via adsorption onto surfaces of minerals and by cleavage upon exposure to UV radiation or ozone. Cleavage of humic molecules seems to be an important step in the decomposition of humic substances by microbes. Easily degradable substrates in the DOC pool (glucose, lactate, etc.) appear to stimulate microbial degradation of humic substances, either by a priming effect of an easily degradable substrate or by bacterial cometabolism. These... 

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