【摘要】 桑园中残留的大量农药,有通过桑树富集最终对家蚕造成不良影响的潜在风险。采用富集培养和平板划线分离的方法,从长期被农药污染的桑园土壤中筛选分离到一株可降解对家蚕有极高风险性的杀虫剂啶虫脒的细菌菌株H2。对分离菌株H2进行形态和生理生化特征及16S r DNA序列分析,鉴定其为产碱假单胞菌(Pseudomonas alcaligenes)。该菌株对啶虫脒的最高耐受浓度为1 200 mg/L;菌株在含300 mg/L啶虫脒的无机盐培养基中培养,0~1 d为生长延迟期,1~4 d为对数生长期,4~6 d为稳定期,6 d后进入衰亡期;菌株在啶虫脒初始质量浓度为300 mg/L的无机盐培养基中培养9 d,对啶虫脒的降解率为62.7%。同时发现H2菌株在分别含1 000 mg/L吡虫啉、1 000 mg/L烯啶虫胺、1 000 mg/L噻虫啉和500 mg/L辛硫磷的无机盐培养基中也能够生长,说明H2菌株能有效降解多种烟碱类农药和有机磷类农药,有望进一步开发为桑园残留烟碱类及有机磷类农药的微生物降解制剂。更多还原

【Abstract】 There is potential risk to silkworm(Bombyx mori)health due to pesticide residues in mulberry field through enrichment by mulberry.A bacterial strain H2,which can degrade acetamiprid that is extremely hazardous to silkworm,was isolated from mulberry field with long-term pollution of pesticides using enrichment culture and streak plate method.Based on the morphological,physiological and biochemical characteristics and the phylogenetic analysis to 16S r DNA sequence,this bacterial strain was identified as Pseudomonas alcaligenes.The maximum tolerant concentration of this bacterium to acetamiprid was 1 200 mg/L.Cultivated in inorganic salt medium with 300 mg/L acetamiprid,the bacterial growth had a lag phase at 0-1 d,a log phase at 1-4 d,a stationary phase at 4-6 d,and a decline phase after 6 d.After 9 d culture in inorganic salt medium with initial acetamiprid concentration of 300 mg/L,the degradation rate of acetamiprid was 62.7%.It was also found that this bacterium could grow in inorganic medium containing 1 000 mg/L imidacloprid,1 000 mg/L nitenpyram,1 000 mg/L thiacloprid and 500 mg/L phoxim respectively,demonstrating its effectiveness in degrading various neonicotinoid and organophosphorus pesticides.Therefore,it is promising to further develop this bacterium into microbial degradation agents against neonicotinoid and organophosphorus pesticides in mulberry field.更多还原