Phenol degradation by halophilic fungal isolate JS4 and evaluation of its tolerance of heavy metals.

Abstract

Phenol is one of the most common pollutants in many kinds of industrial wastewater, some of which are in high salinity, resulting in more difficulties of biodegradation. In this work, a halophilic strain capable of utilizing phenol as sole source of carbon and energy in both hypersaline and no-salt media was isolated and identified as genus Debaryomyces. The optimization of environmental parameters including phenol concentration, pH, dissolved oxygen as well as salinity was carried out and tolerance of heavy metals by the strain was evaluated. The strain Debaryomyces sp. was able to grow in culture when initial phenol concentration, pH, agitation and salinity were at wide ranges (0-1200 mg L(-1), 4.0-10.0, 50-200 rpm, 0 %-15 %, respectively). High removal efficiency was hardly affected in the presence of 5 mM of Zn (II) and Mn (II). Under optimal conditions (pH 6.0, 200 rpm, 1 % of salinity without heavy metals), 500 mg L(-1) of phenol could be completely degraded within 32 h. The high removal efficiency of phenol by the strain with significant variations of process parameters might contribute to the bioremediation of phenol-polluted environments under hypersaline or no-salt conditions.