Biodegradation of two organic ultraviolet-filters by single bacterial strains

Organic ultraviolet filters, including 4-hydroxybenzophenone (4-HBP) and 2,4-dihydroxybenzophenone (BP-1), are persistent emerging contaminants whose presence in the environment has been a threat to aquatic organisms due to their endocrine disruptor’s properties. Their efficient removal from the environment became a priority for the scientific community, especially for finding suitable decontamination technological processes. Up to now, there are no studies reporting the biodegradation of 4-hydroxybenzophenone and 2,4-dihydroxybenzophenone by a specific bacterial strain. In this paper, there were tested, in-vitro , the 4-hydroxybenzophenone and 2,4-dihydroxybenzophenone biodegradation potential of two Gram-positive ( Staphylococcus aureus and Enterococcus faecalis ) and two Gram-negative ( Salmonella typhimurium and Serratia rubidae ), as biological models. The 2,4-dihydroxybenzophenone biodegradation rate, after 24 h incubation with bacterial strains, was 26.7% induced by Staphylococcus aureus and 14.7% by Salmonella thiphymurium . The 4-hydroxybenzophenone biodegradation process was a more specific one since only Gram-negative bacterial strains were successful in biodegrading it. The 4-hydroxybenzophenone biodegradation rates reached up to 12.7% after 24 h of incubation in presence of Salmonella thyphimurium and up to 24.0% after 24 h of incubation with Serratia rubidae . The 4-HBP biodegradation process induced by Serratia rubidae was limited to generation of benzophenone and a multi-hydroxylated derivative of 4-HBP by-products. The data obtained in this study gave important information regarding the 4-hydroxybenzophenone and 2,4-dihydroxybenzophenone potential biodegradation pathways by single bacterial strains. Graphical abstract