Simultaneous biodegradation of phenanthrene and oxidation of arsenite by a dual-functional bacterial consortium

Bioremediation of co-contamination by polycyclic aromatic hydrocarbons (PAHs) and arsenite (As (III)) may be a cost-effective alternative to conventional chemical removal methods. In this study, a heterotrophic bacterial consortium capable of simultaneously degrading PAHs and oxidizing As (III) has been isolated. After 48 h of incubation, the bacterial consortium removed 71.4% of PHE and transformed 96.2% of As (III) to arsenate (As (V)) in liquid culture containing 200 mg I-1 of PHE and 60 mg 1-1 of As (III) under aerobic conditions. A 16S rDNA library was constructed from the consortium to identify the dominant bacteria, which were Pseudomonas, Pusillimonas, Alcaligenes and Achromobacter spp. DGGE profiles showed considerable differences in community structure as the ratio of PHE and As (III) changed. When both PHE and As (III) were present, bacteria from the gamma-Proteobacteria group (Pseudomonas) and beta-Proteobacteria group (Achromobacter and Alcaligenes) were abundant. However, when only PHE was present, Pseudomonas and Achromobacter spp. were dominant, and when only As (III) was present, Pseudomonas and Alcaligenes spp. were the dominant species. The use of the dually functioning bacterial consortium provides a potential application for efficient biotransformation of PAHs and arsenite co-contamination systems. (C) 2013 Elsevier Ltd. All rights reserved.