Nutrients for micro-organisms

One of the limitations of milk as a raw material is its perishability - it is an excellent source of nutrients for micro-organisms as well as for humans. However, this perishability is readily overcome by a well-organized, efficient dairy industry. 

Polyphosphates Hydrolysis to orthophosphate which reacts with calcium to form a sludge. Nutrient for micro-organisms. 

However, even if several building materials are low in potential nutrients there are some exceptions. Available potential nutrients in certain types of building materials are also very variable. Thus, the nutrient content of wood may vary to a great extent (Terziev et al., 1996). Glass wool and mineral wool are in themselves poor substrates, but insulation materials and air filters made of such materials often contain urea-formaldehyde, and dust-binding oils are added which may serve as nutrients for micro-organisms (Morey and Williams, 1990 Bjurman, 1993 Ezeonu et al., 1994 a,b). 

Contamination of building materials by soil, dust or other sources of dirt may add potential nutrients for micro-organisms which support production of MVOCs (Chang et al., 1996). Wallpaper may support microbial growth and production of MVOCs (Fig. 3.7-2). Dust may also function as a sink for MVOCs (Wilkins et al., 1997). 

Cosmetics in particular are multi-component systems containing, besides water, different nutrients for micro-organisms, such as carbohydrates, nitrogenous compounds, biodegradable detergents and emulsifiers and mineral salts. There is always a risk of microbial contamination during the production of... 

The intensity of microbial growth on plastic material depends on the type of synthetic polymer, but also on the type of additives, especially plasticizers used to improve the processing characteristics of the polymer. There are plasticizers such as fatty acid esters and long-chain dicarboxylic acid esters which are most susceptible to fungal growth while phthalate and phosphate esters with alkylol substituents are generally resistant. However, as plastic materials in operation are always subject to contamination with traces of nutrients for micro-organisms. 

G. Metabolic Difference. Micro-organisms attack wood by secreting enzymes into the immediate structure which in turn break down the wood components into small, soluble units that become nutrients for the organism. The main destructive enzyme system the wood-rotters contain is a class of proteins known as cellulases. These enzymes break down he polymeric cellulose, the strong backbone of wood, into digestible units. Humans do not possess this enzyme system consequently, we cannot degrade cellulose-containing materials. 

These uptakes and releases are directly proportional to the quantity of organic nutrients containing carbon made available for micro-organisms. 

If the initial quantities of organic nutrients available for micro-organisms are known, the qirantities of CO2 (or CH4) emitted or O2 absorbed must be accurately measured to deduce the rates of biodegradation. 

Although it is possible to obtain cells from whole animals or plants and to cultivate them in suitable nutrient solutions, in general they are not as easy to handle as microbes. Nevertheless, plant and animal cells are a valuable genetic resource for biotechnology and many newly developed bioprocesses rely on transfer of their genes to micro-organisms. 

For a micro-organism to grow it must be supplied with all the nutrients required for cell material and energy production. 

Although these studies utilizing Incorporated debris are valuable because they show the potential for allelochemlcals to be released from plant litter, they suffer from a disadvantage. The amount of debris added and Its carbon to nitrogen ratio might lead to alterations In nutrient contents In the soil as the result of proliferation or shifts In populations of micro-organisms. Thus, a control In which a material of similar C/N ratio but lacking allelochemlcals needs to be Included for such studies to be conclusive. The above studies did not Include such controls and thus are not definitive. 

Short-chain acids accumulate.under anoxic conditions/-which favor fermentative metabolism of bacteria. Such phytotoxins nay damage the plant directly or predispose plants to infection by pathogens. However plant residues nay also be used as substrates for beneficial micro-organisms to produce plant nutrients, soil conditioners, and plant protection chemicals. There is scope to promote the beneficial microbial effects against the harmful by soil management and by inoculation. 

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