Substrate degradation

An alternative use of added readily degradable substrates is to drive the local environment toward anaerobiosis so that reactions such as reductive dechlorinations or reductive removal of nitro-groups are promoted. 

Are the clean-up standards reasonable Are biological processes known to degrade substrates down to the levels required ... 

Oxygen is used in these microbiolreactions to degrade substrates, in this case organic wastes, to produce energy required for ceU synthesis and for respiration. A minimum residual of 0.5 to 2.0 mg/L DO is usually maintained in the reactors to prevent oxygen depletion in the treatment systems. 

Results from experiments on biodegradation in which readily degraded substrates such as glucose are added have probably restricted relevance to natural ecosystems in which such substrates exist in negligible concentration. However, readily degraded substrates in addition to those less readily degradable undoubtedly occur in biological-waste-treatment systems. In these circumstances, at least three broadly different metabolic situations may exist ... 

Consistent with the preceding comments on the metabolism of xenobiotics in the presence of additional carbon substrates, the result of deliberate addition of organic carbon may be quite complex and will not be addressed in detail. Two examples on rates of mineralization are given as illustration in which addition of glucose apparently elicited two different responses. It should, however, be emphasized that since the concentration of readily degradable substrates in natural aquatic systems will generally be extremely low, the environmental relevance of such observations will inevitably be restricted ... 

The degradation of aniline may be induced by aniline, although both 3- and 4- chloroani-line, which are poor substrates, were able to induce the enzymes for aniline degradation in a strain of Pseudomonas sp. (Konopka et al. 1989). This strain was able to degrade aniline in the presence of readily degradable substrates such as lactate. 

The multilayer shells can also provide a protective barrier for the loaded enzyme in environments where enzyme-degrading substrates such as proteases may be present [67]. Dissolved catalase was inactivated immediately by protease, losing its entire activity within 60 min in solution. For catalase loaded in BMS spheres, inactivation is slower, with an activity loss of about 20 % in 60 min. Notably, a negligible decrease in... 

Under aerobic conditions TNT can be mineralized by a range of bacteria and fungi, often co-metabolically with the degradation of a more degradable substrate There is even evidence that some plants are able to deaminate TNT reductively. 

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