Super Enhancement of Methanethiol Biodegradation by New Isolated Pseudomonas Sp. Coupling Silicone Particles

Abstract

A new strain, Pseudomonas sp. SJ-1, which was able to remove model odorous organics methanethiol (MT) has been isolated from the wastewater treatment plant and identified via 16S rRNA analysis. Initial MT concentration, temperature and pH played an important role in MT removal, and up to 100% of 260 mg L -1 of MT could be removed within 11 h under the optimum conditions (30 o C, pH 7.0) with an average degradation rate of 23.6 mg L -1 h -1 , which was the highest one in literature so far. The silicone particles were added as the non-aqueous phases (NAP) to enhance the performance of MT degradation. The results indicated that the maximum degradation rate and specific cell growth of strain SJ-1 were 2.36 times and 1.31 times by Haldane kinetic model analysis in the NAP added test. The SO 4 2- was identified as the major intermediate and CO 2 as a final product in MT biodegradation. Overall, this is the first report that a newly isolated Pseudomonas sp. could use high concentration MT as sole energy source and carbon source and its activity could be enhanced by adding NAP. The results provide a suggestion for the development of more effective and reliable biological treatment processes.

Keywords: Methanethiol, Pseudomonas sp., Non-aqueous phase, kinetics