Objective Through detecting the structure of bacterial community and the effects of mutation to monitor and regulate the treatment of sewage from biomedical enterprises.
Methods The study used 3M petrifilm aerobic count plates and 3M petrifilm rapid coliform count plates to count the number of bacteria and coliform groups. Sewage was concentrated and its mutagenic effects tested with the Ames test. Polymerase chain reaction (PCR) was conducted to build the 16S rRNA gene library, which was used to monitor the structure of bacterial community.
Results Aerobic bacteria counting showed 3 sampling sites containing more than 108 CFU/mL bacteria. All sampling sites showed a consistent result on coliform count from 103-104/mL. Twenty three species were found in the samples by 16S rRNA gene clone method, mainly including Rhodocyclaceae, Comamonadaceae and Flavobacteriaceae, etc. Human pathogenic Legionella was detected in one sample. Two concentrated sewage samples showed frame shift mutation effect, and dose-effect relationship was shown in another two. Other samples were negative in Ames test.
Conclusion The monitoring of sewage from biomedical enterprises should be established on a strategy of long-term, stable and multiple aspects. Ames test and 16S rRNA gene library analysis need to be involved in evaluating the comprehensive situation and mutagenic ability of sewage as a whole, and actually these two methods could be used in such monitoring.
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