Screening Of High Speed Deodorizing Bacteria For Ethanethioland Optimization Of The Fermentation Conditions

Ethanethiol is a kind of volatile organic sulfur compounds (VOSCs), classified as an odorous, with its very low odor threshold value, high volatility and toxicity. As other odorous, ethanethiol will cause serious environmental problem and threaten the public health. At present, china has take measures to monitor and prevent odorous pollution, but the control and treatment technology are still in the exploratory stage. Methods of ethanethiol treatment are seldom reported. Among all the methods, bio-technologies attract widespread attention because of its efficiency and low cost. So there are more attentions focused on odorous degrading bacteria.This article use ethanethiol as the object of study,46ethanethiol deodorizing bacteria were isolated from soils which were sampled from a chemical plant..The maximum removal rate of strains, numbered for C46, C49, C54, were48.4%,46.9%and42.2%after4h,2h and4h, respectively. According to sampling time, sites and the deodorizing force,10out of46bacteria were chosen to analysis the homology. The results showed that7strains belong to the Bacillus genus, while2strains belong to Aeromonas sp., and1strain belongs to Pseudomonas sp. Combined with the characteristics of morphology and the16S rRNA gene sequencing results, C46,C49and C54were identified as Aeromonas sp., Pseudomonas sp. and Bacillus cereus., respectively. However, Aeromonas are pathogens of aquatic organisms, therefore, in view of practical application, bacteria C49and C54were chosen for subsequent experiments.In order to achieve the industrial production of C49and C54, fermentation conditions were optimized. First screen a more suitable medium, and then single factor and orthogonal experiments were carried out to determine the optimal concentration combination of the substance. The results showed that the strains C49and C54are best grown in LB medium, and it is determined that the optimal compositions of the medium were as follows:yeast extract5g/L,NaCl5g/L, Peptone12.5g/L for C49, yeast extract5g/L, NaCl7.5g/L, Peptone7.5g/L for C54.