论文部分内容阅读
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。
The large amount of pesticides left in mulberry fields has the potential risk of adversely affecting the silkworms through mulberry enrichment. The method of enrichment culture and plate scribing separation was used to screen and isolate a bacterial strain H2 that can degrade acetamiprid which is very high risk to silkworm from mulberry soil polluted by pesticides. The morphological, physiological and biochemical characteristics of the isolated strain H2 and 16S r DNA sequence analysis were identified as Pseudomonas alcaligenes. The maximum tolerated concentration of acetaminophen for this strain was 1200 mg / L. The strain was cultured in inorganic salt medium containing 300 mg / L acetamiprid, 0-1 d for growth delay, 1-4 days for Logarithmic growth phase, 4 ~ 6 d for the stationary phase, 6 d after entering the decay stage; strain of acetamiprid initial mass concentration of 300 mg / L of inorganic salt medium for 9 d, the acetamiprid degradation rate 62.7%. At the same time, it was found that the H2 strain could also grow in an inorganic salt medium containing 1 000 mg / L imidacloprid, 1 000 mg / L nitenpyram, 1 000 mg / L thiacloprid and 500 mg / L phoxim. This indicated that the H2 strain can effectively degrade many nicotine pesticides and organophosphorus pesticides and is expected to further develop a microbial degradation preparation for residual nicotine and organophosphate pesticides in mulberry fields.