Screening and metabolic analysis of high-efficiency molluscicidal bacteria based on atmospheric and room temperature plasma mutagenesis.

Oncomelania hupensis is the only intermediate host of Schistosoma japonicum, highlighting the need for developing low-toxicity, efficient, and economical molluscicides to control schistosomiasis transmission and prevalence. This study screened for effective molluscicides using O. hupensis in an immersion-based biological assay. Bsp dustable powder (DP) emerged as the most effective molluscicide among seven microbial pesticide samples tested. The dominant strain, designated 3-4, was isolated and identified as Bacillus subtilis using 16S rDNA gene sequencing. Following atmospheric and room temperature plasma (ARTP) mutagenesis, a mutant strain library containing 214 strains of bacteria was obtained. Most of the 139 mutant strains showed no significant difference compared with parental strain and 60 strains showed a decrease. Meanwhile, 15 mutant strains with higher molluscicidal effects were obtained. ARTP-129 and ARTP-154, exhibiting the highest positive mutation rates, demonstrated a 64.51 % increase in mortality compared to the parental strain 3-4. Metabolomic analysis revealed that the mutant strains may alter molluscicidal toxicity by regulating the synthesis pathways of metabolites such as l-pyroglutamic acid (PGA). These findings suggest the potential of ARTP mutagenesis for developing novel and effective molluscicides for schistosomiasis control.