Выделение и характеристика штамма-деструктора дибутилфталата Rhodococcus sp. 5A-K4

Abstract

The study is devoted to the ability of the bacterial strain 5A-K4, isolated from the rhizosphere of Puccinellia distans (Jacq.) Parl. plants, growing on the territory of industrial development of the Verkhnekamsk salt deposit (Perm krai), to grow on dibutyl phthalate (DBP) as the single carbon source was studied. Based on analysis of the 16S rRNA gene, the strain was identified as a representative of the genus Rhodococcus. Strain 5A-K4 had the highest level of the 16S rRNA gene similarity (99.86%) with Rhodococcus erythropolis NBRC 15567T. The strain grew effectively on a DBP substrate without addition of salt and at a content of 30 g/L NaCl in the cultivation medium. It has been shown that Rhodococcus sp. 5A-K4 is capable of growth at high concentrations of DBP (up to 12 g/L). The genome of the strain 5A-K4 contained the dpeH and mpeH genes, the products of which are involved in the initial stages of DBP degradation. The nucleotide sequences of the dpeH and mpeH genes are homologous to the sequences of the α/β hydrolase genes of strains of the classes Actinomycetes and Bacilli. Based on the data obtained, a pathway for the degradation of DBP by strain 5A-K4 was proposed. Thus, the rhizosphere DBP degrading strain Rhodococcus sp. 5A-K4 can be used as a bacterial agent in the development of phytoremediation methods for soils contaminated with phthalates.