Degradation of Dibutyl Phthalate by Halotolerant Strain Pseudarthrobacter sp. NKDBFgelt

Dibutyl phthalate (DBP) is the di-n-butyl ester of -phthalic acid, widely used in the chemical industry as a plasticizer and is a common environmental pollutant. The ability of the halotolerant strain sp. NKDBFgelt (VKM Ac-3035) isolated from the rhizosphere soil of a salt mining area (Perm Krai, Russia) to use DBP as the sole source of carbon and energy was studied. The strain NKDBFgelt was capable of growth on DBP and ortho-phthalic acid (PA) at high salinity (up to 30 g/L and 50 g/L NaCl, respectively), as well as growth on DBP at a high concentration — up to 9 g/L. The strain degraded 75.2% DBP (initial concentration 200 mg/L DBP) by 72 h of cultivation in the absence of salt. With increased salinity of the medium (30–70 g/l NaCl), DBP degradation was recorded at a level of 66.95–27.8%. Analysis of the genome of the strain NKDBFgelt revealed clusters of genes involved in the degradation of DBP, PA, benzoic acid, as well as genes encoding enzymes of the main degradation pathways of aromatic compounds. The halotolerant strain sp. NKDBFgelt has a high degradative potential and is promising in the development of new biotechnologies for the restoration of soils contaminated with phthalic acid esters.