Microbial activity occurrence

Microbial activity may produce reactive intermediates that undergo spontaneous chemical transformation to terminal metabolites. This is quite a frequent occurrence, and its diversity is illustrated by the following examples ... 

Whereas the occurrence of surfactants in wastewaters and freshwater has received substantial interest over the last decade, and thus become fairly well documented, the amount of data on surfactants in estuarine or marine waters remains quite limited. However, it has become clear that knowledge of the behaviour of surfactants in freshwater cannot be easily extrapolated to saline waters [1], as both microbial activities and partition coefficients may vary strongly between the two environments. 

This article reviews information gathered from these areas of research which provides the bulk of our present knowledge of metabolism of OSC in petroleum. The order of presentation is that of increasing experimental control over the microbial activities. First, observations of the persistence of OSC in petroleum-contaminated environments and their occurrence in petroleum reservoirs will be presented. In these situations, we exert little or no control over the microbial activities which occur. Next, results from laboratory studies with crude petroleum or petroleum fractions will be presented. Finally, laboratory work with pure OSC will be summarized. Using the latter controlled conditions, metabolic intermediates and pathways for a few OSC have been elucidated. 

Kim, J., and C. E. Zobell (1972), Occurrence and Activities of Cell-Free Enzymes in Oceanic Environments, in R. R. Cowell and R. Y. Morita, Eds., Effect of the Ocean Environment on Microbial Activities, University Park Press, University Park, TX, pp. 368 385. 

The authors have previously (7-9) discussed activities, occurrence and microbial production of pectolytic enzymes. The hemicellulases listed in Table III are produced together with the pectolytic enzymes and are also important for pectin breakdown. The... 

Chloroform, methyl chloroform, and to some extent carbon tetrachloride, trichloroethylene and perchloroethylene inhibit the anaerobic sludge digestion stage of biological sewage treatment, at levels as low as 5 mg/kg on dry sludge solids [8] but there are no reports of any inhibition or aerobic microbial activity at realistic levels of occurrence. 

Literature on microbial physiology and biochemistry may be helpful for the choice of strains to find enzymes for the biotransformation of naturally occurring substances. Screening of enzymes to convert unnatural compounds however usually implies an accidental selection of microorganisms. Actually, even such a preliminary approach gives valuable informations about the occurrance of an enzyme activity. 

Table I gives approximate figures for the /3-glucuronidase activity of nearly all known sources of the enzyme. It can be seen that the enzyme is universally distributed in mammalian tissues and body fluids. This generalization probably extends to other vertebrates, and to insects and molluscs. The occurrence of the enzyme in micro-organisms is random, and bears no relation to their pathogenicity for man. The microbial enzyme may be adaptive or constitutive, and extracellular or intracellular the enzyme in Escherichia coli is adaptive and extracellular, whilst that in...

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