摘要
为建立有效地去除淡水养殖环境中溴氰菊酯残留的微生物修复技术,通过采集长期受菊酯类农药污染土壤样品,以溴氰菊酯为唯一碳源配制基础盐培养基对土样进行富集培养,筛选分离出1株溴氰菊酯降解菌(SW),根据形态、生理生化分析及16S rRNA序列分析,将其鉴定为多食鞘氨醇杆菌(Sphingobacterium multivorum)。通过改变温度、pH、接种量、药物初始浓度等外部条件研究菌株最适降解条件。结果显示:在pH为7的基础盐培养基中,30℃、180 r/min摇床培养120 h,SW对1.0 mg/L溴氰菊酯的降解率达76.4%。溴氰菊酯可作为该菌生长的唯一碳源。SW降解溴氰菊酯的最优条件为30℃、pH 6.0、接种量4%。在溴氰菊酯浓度为0.1、0.5和1.0 mg/L时,降解过程基本符合一级动力学方程模型,降解半衰期(T_(1/2))分别为4.5、2.3和2.0 d。生物修复试验中SW对养殖淡水中0.5、5.0和50μg/L溴氰菊酯作用5 d后的降解率为21.6%,26.4%和53.8%。
Soil samples were collected from the plowland soil exposed to pyrethroid pesticides contamination and were cultured at inorganic salt medium prepared by adding deltamethrin as the sole carbon source to contribute effective mocrobioremediation technology of wiping off deltamethrin residue in aquaculture water.The degradation ability of degrading bacteria was determined by gas chromatography to screen and identify the relevant high-efficiency degrading bacteria strains.A deltamethrin-degrading strain was isolated from soil samples and named as SW.Strain SW was identified as Sphingobacterium multivorum based on the morphology,physio-biochemical characteristics and 16S rRNA sequence analysis.The best degradation conditions of strain were studied by changing the external conditions such as temperature,pH,inoculation,initial concentration of the pesticide,and the effect of bioremediation of deltamethrin in cultured freshwater were explored.When bacterial strain SW was incubated in mineral salt medium contained 1.0 mg/L deltamethyrin at pH 7.0,after 120 h shaking at 180 r/min under 30 ℃,the degradation rates of deltamethyrin reached to 76.4%.The optimal biodegradation conditions were 30 ℃,pH 6.0 and inoculum biomass 4%.Strain SW could not only utilize deltamethrin as the sole carbon source for growth,but also could highly tolerate and efficiently degrade deltamethrin ( 0.1,0.5 and 1.0 mg/L).Furthermore,the degradation reaction followed first-order kinetics and half lives ( T 1/2 )were 4.5,2.3 and 2.0 d,respectively.Strain SW could degrade 0.5,5.0 and 50 μg/L deltamethrin in freshwater with degradation rates of 21.6%,26.4% and 53.8% in 5 days.Deltamethyrin degrading bacteria SW has some remediation effect on freshwater contaminated by deltamethyrin,providing a new approach for microbial remediation of deltamethrin residues in freshwater.
作者
苏志俊
刘永涛
徐春娟
丁浩
余琳雪
艾晓辉
SU Zhi-jun;LIU Yong-tao;XU Chun-juan;DING Hao;YU Lin-xue;AI Xiao-hui(College of Fisheries and Life Science,Shanghai Ocean University,Shanghai 201306,China;Yangtze River Fisheries Research Institute,Chinese Academy of Fishery Sciences,Wuhan 430223,China;Key Laboratory of Control of Quality and Safety for Aquatic Products,Ministry of Agriculture,Beijing 100141,China;Freshwater Aquaculture Collaborative Innovation Center of Hubei Province,Wuhan 430070,China)
出处
《淡水渔业》
CSCD
北大核心
2019年第1期98-106,共9页
Freshwater Fisheries
基金
公益性行业(农业)科研专项(201503108-CC-1)
