石油污染土壤降解细菌的分离、鉴定及生长条件优化

Isolation,Identification and Growth Condition Optimization of Degrading Bacteria of Oil Contaminated Soil

为研究石油污染土壤的微生物修复效果,从大庆油田受石油污染的土壤中分离得到特征明显的3株石油降解细菌(编号18、H、21),这些菌株能以石油为唯一碳源生长。试验通过形态学鉴定以及分子生物学鉴定方法明确了这3株细菌的种属,分别为氧化微杆菌,节细菌和芽孢杆菌。采用单因素试验设计对试验菌株在无机盐培养基中的生长条件进行初步探讨,研究pH、盐浓度、氮源、磷源等因素对菌株生长的影响。结果表明:H菌株的最适生长条件:pH=7,盐浓度为3%;18菌株的最适生长条件:pH=8,盐浓度为3%;21菌株最适生长条件:pH=7,盐浓度为1%。H、18、21菌株的最适氮源分别为KNO3、NH4NO3、NH4Cl。H菌株的最适磷源K2HPO4:KH2PO4为1:2(双磷源),18菌株的最适磷源是K2HPO4,21菌株的最适磷源为K2HPO4。

In order to study the effect of microbe remediation on soil contaminated by petroleum,three strains of petroleum degrading bacteria were isolated from contaminated soil in Daqing oil field,which was named No.18,H and 21 strains,which can use oil as the carbon nutrition for their growth.These three bacterium species had been clearly identified by using morphological and molecular biological methods as micro-bacterium,arthrobacter and bacillus.Single factor test design was used to test the strain growth conditions in inorganic salt medium including pH,salt concentration,nitrogen,phosphorus and other factors.The results showed that the optimum growth conditions was pH=7,NaCl concentration of 3% for strain H,and pH=8,3% salt for No.18 strain as well as pH=7,NaCl concentration of 1% for No.21 strain.The best nitrogen source was KNO3 for H strain,NH4NO3 for No.18 strain and NH4Cl for No.21 strain.The most suitable phosphorus source was K2HPO4：KH2PO4 with the rate 1：2 for No.18 strain,and K2HPO4 for both of No.18 and No.21 strains.