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 (Ki) 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 ofMMWAs is probably caused by biotransformation of HMWAs or non-alkane hydrocarbons to MMWAs.© Taylor & Francis Group, LLC.