Analysis of PCB‐degrading bacteria : physiological aspects

Several aerobic co‐cultures capable of co‐metabolizing polychlorinated biphenyls (PCBs) were acquired by cultivation on biphenyls (BP). The source of micro‐organisms was PCB‐contaminated soil taken from various sites in the Czech Republic. Several bacterial strains (Gram‐negative rods) were isolated, and their capacity to degrade Delor 103 (a PCB mixture containing di‐ to hexachlorobiphenyls) was analysed. This study was focused on co‐culture 319 and isolate 2. The growth parameters of both those cultures were studied on BP ; for isolate number 2 the specific growth rate μ = 0·122 (h−1) was calculated. The degradation of the individual congeners was estimated and resulted in more than 50% of the degradation of nearly all congeners during a 2‐week experiment. Toxicity of Delor 103 on the vitality of the cells was followed by using viable plate count. The viability of the tested strain was preserved in the 100 times higher Delor 103 concentration compared with conditions in degradation experiments.