Abstract
Bacterial degradation of phenols in the environment is influenced by number of factors such as salinity, pH, temperature, and nutrient availability. Halophiles are the group of microorganisms which could grow at saline conditions and thus renders a variety of environmental applications. Moderate halophiles can grow at 3-5% NaCl concentration and are able to utilize a diverse class of toxic pollutants persists in the environment as a result of industrial activities. The moderately halophilic bacterial consortia enriched from wastewater collected from Industrial Effluent Treatment Plant of Yanbu, Saudi Arabia utilized phenol as sole carbon source for its growth. The halophilic consortia could survive and utilize phenol at higher salt concentrations (8% and 12% NaCl). Yeast extract supplied as additional substrate significantly enhanced the phenol biodegradation at higher salt concentrations. The consortia effectively degraded 100% of added phenol within 4 days at haloalkaline conditions (4% NaCl, pH 10). Addition of urea as alternate nitrogen substrate greatly reduced the lag time of the bacterial consortia for the phenol biodegradation. PCR-DGGE analysis of the moderately halophilic bacterial consortia revealed the presence of three dominant strains which are identified as Ochrobactrum sp. SAR1, Pseudomonas sp. SAR2, and Ochrobactrum sp. SAR3. Through this study, the moderately halophilic bacterial consortia can serve as versatile candidate for the treatment of phenol present in saline and alkaline industrial wastewaters. (c) 2017 American Institute of Chemical Engineers Environ Prog, 37: 1587-1593, 2018