可降解蒽细菌的分离与生长特性研究

Research on the Isolation and Growth Characteristics of Anthracene-degraded Bacteria

[目的]为蒽等多环芳烃(PAHs)污染的生物修复提供理论依据。[方法]采用富集培养的方法从污水处理厂的活性污泥中筛选得到蒽降解菌株E12,测定该菌株的生长曲线及其对蒽的降解曲线,并研究不同蒽浓度、初始pH值等对其降解蒽效率的影响。[结果]经初步鉴定,菌株E12属于气微菌属,该菌株可在以蒽为唯一碳源的培养基中生长。蒽初始浓度小于900mg/L时,菌体浓度随蒽浓度的增加而增加,当蒽浓度超过900mg/L后,菌体浓度显著下降;菌株在弱酸性和弱碱性环境中均能生长,但最适生长pH值为6.5;菌悬液接入量对菌体生长也有明显影响,最适接种量为2.0%。[结论]E12菌株降解蒽的最佳条件为:蒽浓度900mg/L,pH值6.5,此条件下培养148h后蒽的降解率可达70.5%。

[Objective] The research aimed to supply theoretical foundation for bio-recovery of polycyclic aromatic hydrocarbon（PAHs） pollution,such as anthracene pollution.[Method] The anthracene-degraded strain E12 was screened out from active sludge of sewage processing factory through enrichment culture.The growth curve of this strain and its degrading curve on anthracene were determined and the influence of factors including different anthracene concn.and initial pH values on the its degraded efficiency was researched.[Result] The primary identification indicated that the strain E12 belong to Aeromonas and could grow in the medium with anthracene as sole carbon source.When the initial concn.of anthracene was lower than 900 mg/L,the strain concn.was increased along with the increase of anthracene concn.When the anthracene concn.exceeded 900 mg/L,the strain concn.was decreased significantly.The strain could grow in both weak acid and weak base environments and the optimum pH value for its growth was 6.5.The innoculation amount of bacterial suspension also showed obvious influence on its growth and the optimum innoculation amount was 2.0%.[Conclusion] The optimum condition for E12 strain degrading anthracene was as follows：the anthracene concn.was 900 mg/L and the pH value was 6.5.The degraded rate of anthracene could reach 70.5% after culture for 148 h under this condition.