柴油降解菌的筛选及其降解特性研究

Isolation of Oil Degradation Bacteria and Its Characteristics in Bio-degradation to Diesel Oil

采用生物驯化法,从石油污染土壤中以0#柴油为惟一碳源通过富集培养分离筛选出9株菌。利用紫外分光光度法对菌株降解能力进行测定,发现一株菌在柴油初始浓度为500mg·L-1的培养液中,振荡培养3d降解率达到了71.7%,具有开发潜力,可以提高石油污染土壤生物修复效率。通过对其形态特征和生理生化特性的分析,初步鉴定该菌株为假单胞菌属。并分析了培养时间、pH值、接种量、温度、柴油浓度、N源6个因素对菌株生长量和柴油降解率的影响。结果表明,该菌株在培养时间为6d、pH值为5.0、接种量为5%、温度为35℃、柴油浓度为1000mg·L-1、N源为(NH4)2SO4的条件下生长旺盛,降解率达到了80%。

In order to enhance the bioremediation of oil-contaminated soil, nine diesel oil degradable strains were obtained from oil-contam- inated soil by using screening cultural medium method which using 0^# diesel oil as the sole carbon source. The degradation ratio of diesel oil by the strains was tested by using ultraviolet spectrometry method. One of the strains showed potential for further utilization with a degradation ratio of diesel oil by 71.7% incubating for 3 days in an culture medium with initial diesel oil concentration by 500 mg·L^-1. Based on the mor- phological, physiological and biochemical test results, the strain was identified as Pseudomonas sp.. And six factors that affect the strain growth and the degradation ratio to diesel oil, such as pH value of the culture medium, temperature, inoculation amount, N source, initial diesel oil concentration and incubation time, were also studied in the proposed paper. The result showed that the optimum culture condition for Pseudomonas sp. strain was pH5.0, inoculation by 5%, （NH4）2SO4 as the N source in the culture medium and incubation under 30 ℃. When the proposed strain grows under this condition, 80% of the diesel oil could be degradated with an initial concentration of 1 000 mg·L^-1 and incubating for 6 d.