Development of a quantitative method for functional gene detection in pulp and paper wastewater treatment systems.

摘要

The recent development of culture-independent methods has revolutionized the study of complex microbial communities such as those present in activated sludge treatment systems. DNA probes that hybridize to genes coding for key enzymes that catalyze microbial processes have been widely used. Can such probes be used to quantify target genes and thus quantify the potential of a microbial community to carry out a reaction of interest?;Optimal conditions for DNA extraction, probe validation, hybridization, and activity measurements were determined for the pulp and paper treatment system environment under study. Using gene probes for key denitrification genes (nirS, nirK), the correlation between denitrifiers and denitrification activity in an enrichment culture and activated sludge samples was tested. The same correlation between nitrogen fixation and nitrogen-fixing bacteria in primary clarifiers was assessed using a probe for the gene encoding a component of the nitrogenase enzyme (nifH). This work was successful in establishing the correlation between gene numbers and their corresponding enzymatic activity and thus supports the quantitative hybridization approach for the monitoring of microbial communities. (Abstract shortened by UMI.).