Using the sulfide-oxidizing bacterium Geobacillus thermodenitrificans to restrict H2S release during chicken manure composting
Xiaohua Wu, Jiahui Wan, Qingda Wang, Zongzheng Liu, Yongzhen Xia, Luying Xun, Huaiwei Liu
Abstract
Hydrogen sulfide (H 2 S) is a toxic gas massively released during chicken manure composting. Diminishing its release requires efficient and low cost methods. In recent years, heterotrophic bacteria capable of rapid H 2 S oxidation have been discovered but their applications in environmental improvement are rarely reported. Herein, we investigated H 2 S oxidation activity of a heterotrophic thermophilic bacterium Geobacillus thermodenitrificans DSM465, which contains a H 2 S oxidation pathway composed by sulfide:quinone oxidoreductase (SQR) and persulfide dioxygenase (PDO). This strain rapidly oxidized H 2 S to sulfane sulfur and thiosulfate. The oxidation rate reached 5.73 μmol min −1 ·g −1 of cell dry weight. We used G . thermodenitrificans DSM465 to restrict H 2 S release during chicken manure composting. The H 2 S emission during composting process reduced by 27.5% and sulfate content in the final compost increased by 34.4%. In addition, this strain prolonged the high temperature phase by 7 days. Thus, using G . thermodenitrificans DSM465 to control H 2 S release was an efficient and economic method. This study provided a new strategy for making waste composting environmental friendly and shed light on perspective applications of heterotrophic H 2 S oxidation bacteria in environmental improvements. • Geobacillus thermodenitrificans DSM465 can effectively oxidize H 2 S to sulfane sulfur and thiosulfate. • DSM465 fitted the process well and effectively decreased H 2 S emission by 27.5% during composting. • DSM465 also increased sulfate content by 34.4%, which improved nutrient composition of the compost.