关键词: 甲硫醚, 嗜麦芽寡养单胞菌, 降解, 动力学, 环境

Abstract:

Dimethyl sulfide (DMS) is one of the most important volatile organic sulfur compounds. Due to its malodorous smell and the extremely low odor threshold, DMS has become a critical issue in wastewater collection and treatment systems. In this study, a novel strain JLM-8, with capability of degrading DMS as sole carbon and sulfur source, was isolated from the active sludge of a pharmaceutical plant. Based on the morphological, physiological and biochemical properties as well as its 16S rDNA gene sequence analysis, the strain JLM-8 was identified as a member of Stenotrophomonas maltophilia. The strain could degrade approximately 100% of 50 mg·L^-1 DMS within 8 hours at pH 7 and 30℃. Response surface methodology (RSM) analysis showed that the optimum conditions for degradation were at pH 7.5 and 31.3℃, using an inoculum amount of 25 mg·L^-1. Under these conditions, approximately 97.9% of DMS was degraded. The kinetic parameters q_max, K_s, and K_i were established to be 2.37 h^-1, 143.55 mg·L^-1, 51.35 mg·L^-1, respectively. The critical inhibitor concentration was determined to be 78.46 mg·L^-1. Research on the characterization of DMS degradable bacteria can provide a new theoretical and technical fundamental basis for bioremediation of DMS-contaminated environments.

Key words: dimethyl sulfide, Stenotrophomonas maltophilia, degradation, kinetics, environment