Investigations showing the possibility of BTX biodegradation present in the water environment under aerobic conditions have been presented. The effects of transformation of benzene, toluene, o-xylene and p-xylene by indigenous to sewage microorganisms as well as by isolated species of bacteria like Aeronwnas sobria, Bacillus steareothermophilus, Enterobacter sakazaki, Pseudomonas aeruginosa. Staphylococcus lentus and the mixture of these species varied distinctively. The results and calculated degradation rates have been compared to some results given by other authors. In aerobic conditions all investigated aromates have shown to be biodegradable. The highest rate of degradation was found for indigenous to municipal sewage microorganisms.

Investigations showing the possibility of BTX biodegradation present in the water environment under anoxic conditions have been presented. The effects of transformation of benzene, toluene, o-xylene and p-xylene by indigenous to sewage microorganisms as well as by isolated species of bacteria like Aeromonas sobria, Enterobacter sakazaki, Pseudomonas aeruqinosa, Staphylococcus lentus and the mixture of these species varied distinctively. The results and calculated degradation rates have been compared to some results given by other authors. In anoxic conditions all investigated aromates have shown to be biodegradable. The highest rate of degradation was found for isolated species of bacteria from municipal sewage.