Evaluation of the Biotechnological Potential of New Bacterial Strains Capable of Phenol Degradation
В. Н. Поливцева, Tatyana Anokhina, Leila Iminova, Oksana V. Borzova, Т. З. Есикова, Inna P. Solyanikova
Abstract
Abstract A number of bacteria, including rhizospheric bacteria, capable of transforming aliphatic and aromatic compounds to varying degrees were isolated from clean soils and soils contaminated with polycyclic aromatic hydrocarbons. Seven bacteria capable of decomposing phenol at a concentration of at least 500 mg/L were selected. Identification by the 16S rRNA gene showed that they belong to the genera Rhodococcus, Pseudomonas, Stenotrophomonas, Lysinibacillus, and Isoptericola. Determination of the activity of phenol destruction enzymes in these cultures showed the absence of a meta-pathway of catechol cleavage during phenol degradation. The activity of catechol 1,2-dioxygenase and protocatechuate 3,4-dioxygenase was detected in cell-free extracts. The activity of the latter enzyme was 15 times higher than the catechol 1,2‑dioxygenase, that was described for the first time for members of the genus Isoptericola. Strains isolated from the rhizosphere of plants growing in contaminated soil were capable of destroying up to 15 individual pollutants, such as aliphatic hydrocarbons, chlorophenols, 2,4,5-trichlorophenoxyacetic acid, and caprolactam. The presence of enzymes, such as β-galactosidase and lysine-decarboxylase, was shown with the use of biochemical test systems for representatives of the genera Stenotrophomonas and Isoptericola. The isolated bacteria can be used both to create biopreparations for bioremediation and to create producer strains for the target enzymes.