Degradation of Mono-Hydroxybiphenyls by Aerobic Strains Isolated from the Bacterial Associations Breaking Down Aromatic Pollutants
Year: 2024
Type: article
Abstract: Micrococcus sp. PNS1, Ochrobactrum sp. PNS5, Stenotrophomonas sp. PNS6, Pseudomonas sp. PNB3, Brevibacterium sp. PNB5, Achromobacter sp. PNB6, and Bosea sp. PNB7 were isolated from the PN2 and PN2-B associations and screened for their ability to degrade mono-hydroxylated biphenyls with hydroxyl groups at the C 3 or C 4 atoms in the biphenyl molecule. The maximum degradation efficiency was 98 % for 3-hydroxybiphenyl and up to 100 % for 4-hydroxybiphenyl with various strains. All strains showed amplification of a fragment of the bph A gene encoding biphenyl-2,3-dioxygenase biosynthesis. Sequence analysis of the bph A gene revealed a distinct branch on the tree topology, indicating its similarity level with known sequences of this gene. Pseudomonas sp. PNB3 was found to possess the ben A gene encoding benzoate-1,2-dioxygenase biosynthesis and positioned on the same evolutionary branch as the benA gene from the well-known biphenyl degrader Pseudomonas putida KT2440. The results obtained demonstrate that the transformation of 3-hydroxy- and 4-hydroxybiphenyls by the isolated strains occurs through dioxygenation of the unsubstituted ring of the biphenyl molecule, with subsequent cleavage into 3- and 4-hydroxybenzoic acids, respectively. Therefore, the strains that were examined are promising for potential application in technologies aimed at degrading both chlorobiphenyls and hydroxylated biphenyls.
Authors: T. D. Kir’yanova, D. O. Egorova
Language: English
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4402750722