Low-temperature biodegradation of petroleum hydrocarbons (n-alkanes, phenol, anthracene, pyrene) by four actinobacterial strains

Abstract

In this study we evaluated the ability of four cold-adapted bacterial strains to degrade n-alkanes (C12–C22), aromatic hydrocarbons (phenol) and polyaromatic hydrocarbons (anthracene, pyrene) at low temperatures. All four strains belonged to the phylum Actinobacteria and were identified as Rhodococcus erythropolis (strain BZ4), Rhodococcus cercidiphyllus (strain BZ22), Arthrobacter sulfureus (strain BZ73) and Pimelobacter simplex (strain BZ91). The strains could grow over a temperature range of 1–30 °C and showed catechol-1,2-dioxyogenase activity. One of the strains, R. erythropolis BZ4, degraded all of the compounds tested. The strain utilized n-alkanes and high amounts of phenol (7.5 mM), anthracene and pyrene (50 mg l−1) at 15°C. P. simplex BZ91 degraded n-alkanes as well as up to 7.5 mM phenol; phenol degradation was observed at 1–30 °C. R. cercidiphyllus BZ22 fully degraded C12 (700 mg l−1) at 1–20 °C, while degradation of C16 and C20 was delayed and lower compared to C12 degradation. A. sulfureus BZ73 was the best phenol degrader and utilized up to 12.5 mM phenol; phenol degradation occurred over a temperature range of 1–25 °C. Such strains are promising candidates for low temperature (low-energy) treatment of industrial wastewaters contaminated with hydrocarbons.