Soil and water microorganisms play an important role in maintaining ecosystem environmental quality. In fact, the ability of soil and water to recover from chemical contamination is primarily dependent on the presence of a microbial community with the ability to remove it. Furthermore the microbial community characteristics of an ecosystem can indicate changes in resource availability and the presence of pollution. In this way, the microbial community represents an important key to understanding the impacts of environmental and anthropogenic factors on ecosystems. Pollution may influence soil and water quality and productivity, but little is known on the effects on microbial communities, and consequent impacts on its functioning. Due to their small size, large numbers, and ubiquitous distribution in the environment, microorganisms are valuable indicators of the occurrence of disturbances due to exogenous physico-chemical stressors. Soil and water microcosm studies enable studying the effects of selective pressures, such as the xenobiotic occurrence, under controlled conditions, on natural microbial communities. In this work we report the results of microcosm degradation studies, using natural soil and water samples, in which the environmental fate of several pesticides and pharmaceuticals in soil and water ecosystems has been evaluated. The biotic and abiotic degradation was evaluated comparing the microbiologically active microcosms treated with the parent compound (e.g. pesticide or pharmaceutical) with others previously sterilized. The disappearance time of 50% of the parent compound applied (DT50) was calculated for each chemical and condition (presence/absence of microbial community). Moreover the formation of the main degradation products was also determined. The results here presented show the key role of microorganisms in the degradation and of the chemicals studied and how this approach can contribute to assess more realistic environmental exposure scenarios.
Microcosm studies to evaluate microbial potential to degrade pollutants in soil and water ecosystems
Grenni P;Barra Caracciolo A
2011
Abstract
Soil and water microorganisms play an important role in maintaining ecosystem environmental quality. In fact, the ability of soil and water to recover from chemical contamination is primarily dependent on the presence of a microbial community with the ability to remove it. Furthermore the microbial community characteristics of an ecosystem can indicate changes in resource availability and the presence of pollution. In this way, the microbial community represents an important key to understanding the impacts of environmental and anthropogenic factors on ecosystems. Pollution may influence soil and water quality and productivity, but little is known on the effects on microbial communities, and consequent impacts on its functioning. Due to their small size, large numbers, and ubiquitous distribution in the environment, microorganisms are valuable indicators of the occurrence of disturbances due to exogenous physico-chemical stressors. Soil and water microcosm studies enable studying the effects of selective pressures, such as the xenobiotic occurrence, under controlled conditions, on natural microbial communities. In this work we report the results of microcosm degradation studies, using natural soil and water samples, in which the environmental fate of several pesticides and pharmaceuticals in soil and water ecosystems has been evaluated. The biotic and abiotic degradation was evaluated comparing the microbiologically active microcosms treated with the parent compound (e.g. pesticide or pharmaceutical) with others previously sterilized. The disappearance time of 50% of the parent compound applied (DT50) was calculated for each chemical and condition (presence/absence of microbial community). Moreover the formation of the main degradation products was also determined. The results here presented show the key role of microorganisms in the degradation and of the chemicals studied and how this approach can contribute to assess more realistic environmental exposure scenarios.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
