Showing papers on "Microbial biodegradation published in 1982"

Environmental Microbiology: Biodegradation

Abstract: A genuinely new dimension to microbiology concerns the fate of synthetic compounds dispersed throughout the biosphere, with xenobiotic compounds representing a major challenge to the metabolic versatility of microorganisms While microbial biodegradation of many of these compounds proceeds by the activity of single species of microorganisms, this paper develops the argument that microbial communities function by synergistic mechanisms to effect the breakdown of many of these compounds The degradation of some compounds, especially xenobiotic compounds, depends on the use of gratuitous metabolic pathways evolved for natural compounds, which in many instances may be evolved through the combined metabolic activity of two or more microorganisms The role of plasmid coded pathways is also considered in the context of the evolution of novel pathways

Microbial Interactions with Several Munitions Compounds: 1,3-Dinitrobenzene, 1,3,5-Trinitrobenzene, and 3,5-Dinitroaniline.

Abstract: : The microbial degradation of 1,3-dinitrobenzene was complete or near complete in Tennessee River water but not in all other environmental water sources tested. Microorganisms from the Tennessee River could utilize 1,3-dinitrobenzene as a sole carbon source for growth and could mineralize the compound. The half-life of 1,3-dinistrobenzene at 25 C and 1,000,000 colony-forming units per milliliter was approximately 1 day in Tennessee River water samples and slightly less than 10 days in the presence of enrichment cultures developed from the samples. The differences in the measured half-lives likely reflects basic microbiological differences in two approaches used to obtain half-lives. Decreases in the concentrations of 1,3,5-trinitrobenzene and 3,5-dinitroaniline mediated by microorganisms in Tennessee River water samples were incomplete and unsustained. Maximum reductions in the concentrations of the compounds required the presence of sediments and even then we were slow. Neither compound would serve as a carbon source for microbial growth, but both compounds were metabolized in the presence of added nutrients. The metabolism of the compounds did not lead to their ultimate biodegradation. Nitro group reduction was seen to occur with both 1,3,5-trinitrobenzene and 3,5-dinitroaniline in the presence of added nutrients and laboratory cultures of Tennessee River microorganisms and also occurred with 1,3,5-trinitrobenzene in Tennessee River water samples. (Author)