Isolation, characterization and S2−-oxidation metabolic pathway of a sulfur-oxidizing strain from a black-odor river in Beijing

Abstract

A single strain capable of efficient S2−-oxidizing was isolated from a black-odor river in Beijing. The single strain was identified as Stenotrophomonas through the physiology and biochemical characteristics as well as the 16S rRNA sequencing experiment. This strain was named as Stenotrophomonas sp.sp3 (strain sp3). The experimental results showed that for the strain sp3 growth and S2− oxidization, the optimal conditions were as follows: 25 °C of temperature, initial pH 7, 2.5 g/L of initial glucose concentration and 1.00 g/L of initial cell concentration. It was found that there were 31 kinds of sulfur oxidation-related genes in the strain sp3 through the whole genomic analysis. The results of the transcriptome analysis suggested that the main metabolic pathway of S2− to SO42− was the paracoccus sulfur oxidation process. The bioconversion processes of S2− to S0, S2− to SO32−, S2O32− to S0 and SO32−, and SO32− to SO42− were controlled by hdrA, cysIJ, tst and sox gene, respectively. HIGHLIGHTS This study found a novel SOB, i.e. Stenotrophomonas sp. sp3, that was capable of sulfur oxidation.; It was proved that S2− could be converted into SO42− via the paracoccus sulfur oxidation process.;

Keywords

• black-odor river
• metabolic pathway
• oxidation characteristics
• s2−-oxidizing bacteria
• sulfide