Microbiology Notes

 Bacterial Metabolism: Introduction: Metabolism refers to all the biochemical reactions that occur in a cell or organism. The study of bacterial metabolism focuses on the chemical diversity of substrate oxidations and dissimilation reactions ,which normally function in bacteria to generate energy. metabolism has an energy-generating component, called catabolism (exergonic), and an energyconsuming, biosynthetic component, called anabolism (andergonic). Catabolic reactions or sequences produce energy as ATP, which can be utilized in anabolic reactions to build cell material from nutrients in the environment. Metabolic pathways of energy generation (ATP) Carbohydrates (particularly glucose), lipids, and protein are the most commonly oxidized compounds. Biologic oxidation of these organic compounds by bacteria results in synthesis of ATP as the chemical energy source. This process also permits generation of simpler organic compounds (precursor molecules) needed by the bacteria ce...

  Microbial degradation of hemicellulose (Enzymes, Steps, Mechanisms): What is hemicellulose? Hemicellulose is a group of complex polysaccharides that are found in the fibers of  plants  along with other polysaccharides like  cellulose  and pectin. Hemicellulose consists of a heterogeneous group of  carbohydrates  where the structures of these carbohydrates are not clearly understood. The structures and physicochemical properties of polysaccharides are very different from each other. Hemicelluloses are not structurally related to cellulose, nor do they contain the same building blocks but they are partially soluble in water or alkali. Hemicelluloses are mostly mixed polymers, whereas cellulose is a homopolymer of glucose. Apart from arabinogalactan, all other hemicelluloses have short side-chains and low molecular weights. The hemicelluloses consist of either pentose (xylose, arabinose) or hexoses (glucose, mannose, galactose) as well as uronic acids. ...