Biodegradation of petroleum hydrocarbons by Neosartorya sp. BL4

Abstract

A new petroleum hydrocarbon-degrading fungus, isolated from an oil contaminant soil, was identified as Neosartorya (teleomorph of Aspergillus) sp. This isolate was able to degrade total petroleum hydrocarbons (TPHs) without a lag phase, but degradation rates decreased with increasing initial TPH concentrations (5,000–20,000 mg L⁻¹). The TPH degradation by the isolate showed a substrate inhibition behavior with an inhibition constant (K_i) of 1,860 mg L⁻¹. Dual lag phase of TPH degradation indicated the ability to adapt its metabolic activity to utilize different types of hydrocarbons as an electron donor. Initially n-alkanes were rapidly removed without lag phase in the whole range of substrate and heavy molecular weight alkanes (HMWAs; C23-C24) and low molecular weight alkanes (LMWAs C9-C15) out of n-alkane hydrocarbons were degraded rapidly, whereas the removal of mid molecular weight alkanes (MMWAs; C16-C22) was relatively slower. Relatively slow degradation of MMWAs is probably caused by biotransformation of HMWAs or non-alkane hydrocarbons to MMWAs.

Keywords:

• Petroleum hydrocarbons
• Neosartorya sp.
• biodegradation
• fungus
• alkanes

Acknowledgments

This study was supported by RP-Grant 2009 of Ewha Womans University.