Isolation And Degradatioon Characters Of A Triclosan Degrading Bacterial Strain

Triclosan, an antimicrobial agent and preservative, has been incorporated into abroad array of personal care products and other consumer products, such as soap,mouthwash, toothpaste, cosmetic, cleaning product and hairspray, also includessterilizing things for medical and textile. In recent years, approximately350tons oftriclosan are presumably produced annually in Europe. TCS is a persistent organicpollutant in its natural medium due to the increasing application. Presently, manycountries has concerned about the ecological and environmental impacts of TCS.According to reports in the literature, it has been detected in aquatic environment inthe worldwide, even in human body. TCS is a kind of chlorophenol compounds, andits metabolites (dioxin-like compounds and chloroform) are the main jeopardy.Therefore, it is a topic worth studying. Some studies have shown that triclosan can bephotodegraded, but compared to chemical and physical degradation, biodegradation isthe most effective and comprehensive method to remove them from naturalenvironment due to its speed and no secondary pollution。In this paper，we analyzed the distribution characters of TCS and TCC in naturalenvironment.There are TCS and TCC in most of environmental samples. This resultsindicated that the kind of organics pollution is increasingly common. A strain whichcan utilize the TCS as the sole carban source and energy was isolated from WWTP,which named H2C. According to molecular biology technology, we would make apreliminary decision on H2C, which could be belong to Sphingomonas. It isworthwhile to note that H2C can biodegradate TCS completely in24h. In addition, itsmetabolites had no toxicity. Therefore, further understanding of the resistance genesand their survival mechanism in natural environment is particularly important.The microbial fingerprinting showed that the structure of microbial communitychanged in the medium containing TCS with increasing acclimation time. Thebiodiversity began to decline. Among them, the flora which can’t tolerate TCScontinue to vanish, and the dominant flora is gradually increased. Finally, theconstruction and initial analysis of Fosmid Library were investigated in this paper. However, the data indicated that the clones which have dioxygenase activity andTCS-resistance can’t degradate TCS. And the test results of terminal sequenceindicate that the clones which have TCS-resistance were mostly belonging toCitrobacter.