Ecological Interactions Between Metals and Microbes That Impact Bioremediation

摘要

Previous work showed the correlation between bacterial biomass, population structure and the amount of lead, chromium and aromatic compounds present along a 21.6 m transect in which the concentrations of both heavy metals (Pb and Cr) and aromatic compounds varied 2-3 orders of magnitude. This work suggested that (a) biomass level was better correlated to the level of biodegradable organic C than the level of heavy metals, (b) microbial community composition differed between highly contaminated soils and uncontaminated ones, and (c) substantial microbial activity was found even in the highly contaminated soils. One confounding factor in these analyses was that the contaminated soils contained Pb, Cr, and aromatic hydrocarbons. Therefore, it was difficult to determine which factors were most important in the shifts of microbial community composition. Therefore, experiments were conducted in microcosms in which individual factors could be systematically varied. In this case, soils were used from the Seymour, IN site which had low levels of contamination, and the microbial community had little chance to adapt to heavy metals or aromatic compounds.