Insights of microbial community evolution under benzisothiazolinone exposure in different soil environments

Benzisothiazolinones (1, 2-benzisothiazoline-3-one; BIT) is widely used to control bacterial and fungal diseases of various crops, and their residues in soil may play an important role in the interaction between soil microorganisms. We studied microbial remediation in five representative soils under different soil conditions (unsterilized, sterilized and flooded) using 16S rRNA gene sequencing to investigate the effect of microorganisms on the degradation of BIT residues in soils to minimize the potentially toxic effects of BIT. High-throughput sequencing data showed that the structure and abundance of bacterial communities in BIT soils changed greatly, which might affect their degradation pathways, while Principal Coordinates Analysis (PCoA) results showed that there was no significant difference in the fungal community in different treatments of the five soils, but the degradation rate of BIT was more influenced by anaerobic microorganisms. Furthermore, Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, and Acidobacteria were the predominant bacterial phyla, accounting for 93.74% of all OTUs, which played an important role in the degradation of BIT. Lysinibacillus had a high relative abundance (21.10%) under flooded treatment conditions in Jilin soil, and its bioremediation may be a reason for the rapid degradation of BIT in flooded treatment. Besides, only soil organic matter (SOM) and pH among the soil properties had significant effects on the microbial community. Based on the further analysis of bacterial phenotype, some microorganisms related to the biodegradation of BIT were found, mainly belonging to Proteobacteria, Bacteroidetes and Firmicutes. This study provides a useful theoretical basis for the biodegradation of BIT using isolated microorganisms.