Effects of different environmental and operating conditions on sulfate bioreduction in shake flasks by mixed bacterial culture predominantly Pseudomonas aeruginosa

摘要

The performance of an acclimatized mixed microbial consortium obtained from a wastewater treatment plant was investigated for its potential to reduce SO42- under different operating conditions. The effect of pH, temperature, initial SO42- concentration, suspended and attached growth reactor configuration, and different carbon sources was investigated in this study. SO42- was completely utilized within 15 d of reactor run from an initial concentration of 1,000 mg/L utilizing lactate as the sole carbon source. Compared to other carbon sources tested in this study, lactate proved to be better for SO42- reduction by the mixed consortium. The optimum conditions for SO42- reduction by the enriched mixed culture were found to be 30 degrees C and pH 7.0. The 16S rDNA analysis of the acclimatized consortium showed that Pseudomonas aeruginosa was the predominant strain in the mixed culture. For the first time, mixed culture with predominantly P. aeruginosa has been reported to be involved in SO42- reduction except one limited report on the SO42- reducing capacity of the bacteria of genus Pseudomonas.