Screening of Dioxin Biotransformation Bacteria from the Contaminated Soil

Abstract

The isolation and preliminary characterization of the indigenous dioxin-biotransformation bacteria of Taiwan was conducted in this study. After that, the culture enrichment, and strains acclimation were also carried out for the isolated strains. The soil samples, Tainan#1, Tainan#2 and Tainan#3 were gathering from the downstream of the announced dioxin contamination site in southern part of Taiwan, and analyze PCDDs/PCDFs concentration to confirm the contamination of the soil. According to the results, Tainan#3 has the highest total toxic equivalence about 2450 ng-TEQ/kg of the contaminants. After go through ten sub-culture inoculums, four bacteria strains which can survive in dioxin media were isolated. The identification results shown these strains were Achromobacter xylosoxidans, Ochrobactrum anthropi, Ralstonia mannitolilytica, and Agromyces sp.. The morphology of the strains revealed that all of the strains are gram's negative. The configuration of the strains presented that Ochrobactrum anthropi and Agromyces sp. obtain the length and width of 2µm and 1µm, which are bigger than others. Phylogenetic analysis showed that Agromyces sp. is the closest with Mycobacterium chlorophenolicum strain PCP-1, which is a PCP degrading bacterium in which the relationship with bootstrap value of 95.