A Dibenz[a,h]Anthracene-Degrading Strain Amycolatopsis sp. Y1-2 from Soils in the Coal Mining Areas

Abstract

It is well-known that the high-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs) are difficult to degrade, and they can cause tremendous damaging effects in environment. In this article, a novel dibenz[a,h]anthracene (DBA)-degrading strain Amycolatopsis sp. Y1-2 was isolated and identified from the contaminated soils in the coal mining areas. The degradation of HMW-PAHs by strain Y1-2 could be improved by adopting DBA, benzo(a)anthracene, benzo(b)fluoranthene, benzo(a)pyrene, and benzo(g,hi)perylene as the sole carbon and energy sources. The co-metabolism substrates test revealed that the HMW-PAHs degradation efficiency of strain Y1-2 could be significantly improved under co-metabolism substrates, especially glucose (increased by 34.70%) and cyclodextrin. The optimization results of DBA-degrading conditions obtained from response surface analysis are as follows: pH 7.6, concentration of DBA 10.71 mg L⁻¹, inoculum amount 1.58 g 100 mL⁻¹ medium, concentration of glucose 9.98 g L⁻¹, and concentration of cyclodextrin 2.05 g L⁻¹. The predicted value of degradation percentage in the optimized conditions was 99.03% (very similar with the actual value of 97.84%). Based on the above results, the strain Y1-2 can degrade HMW-PAHs effectively and will be applied in treating PAHs-containing soils and industrial wastewater.

Keywords:

• Amycolatopsis sp.
• biodegradation
• HMW-PAHs
• RSA

Acknowledgment

We would like to thank the Scistd technical analysis center of Qingdao for 16S rDNA analysis.

Additional information

Funding

This research was supported by the Science and Technology Program of Shanxi Province (No. 20120312066-2) and the Water Conservancy Science and Technology Research and Promotion Program of Shanxi Province (No. 2015SHJ3).