离子注入不动杆菌的降解特性

马睿 蔡长龙 梁海锋 严一心

摘要 [目的]选育能够高效降解石油烃的不动杆菌。[方法]采用低能N+对不动杆菌菌株a8进行诱变，测量离子注入前后不动杆菌对石油烃的降解率，并研究其降解能力和降解机理。[结果]当N+的注入能量和注入剂量分别为15 keV和8.0×1015 ions/cm2时，不动杆菌的降解率可提高至95.03%；利用该注入参数对出发菌种a8进行3次连续诱变后，获得1株能有效降解59种烷烃的突变菌株AQ-15；结合分子生物学技术，对AQ-15降解长链石油烷烃的酶AlmA基因进行分析，发现酶结合位点之一的47th氨基酸由原来的天冬氨酸（Asp，D）变为甘氨酸（Gly，G），从而提高了酶的活性，达到了高效降解长链石油烷烃的效果，揭示了离子注入后不动杆菌降解率提高的机理。[结论]选育出1株能够高效降解石油烃的不动杆菌菌株AQ-15。

关键词 离子注入；不动杆菌；降解率；降解机理

中图分类号 X172 文献标识码 A 文章编号 0517-6611（2017）07-0001-03

Degradation Characteristics of Ion Implantation Acinetobacter

MA Rui， CAI Chang-long， LIANG Hai-feng et al

（Xian Technological University， Ion Beam Bioengineering and Biodiversity Research Center， Xian， Shaanxi 710021）

Abstract [Objective] The aim was to screen out Acinetobacter strains which could effectively degrade petroleum hydrocarbons. [Method] We mutated Acinetobacter strain a8 by low energy N+， measured degradation rate of Acinetobacter strain a8 to petroleum hydrocarbons before and after ion implantation， and studied its degradation ability and degradation mechanism. [Result] When the injection energy and injection dosage were 15 keV and 8.0×1015 ions/cm2 respectively， the degradation rate of Acinetobacter reached 95.03%； through three continuous mutation of start strain a8 under above injection parameters， a mutant strain AQ-15 which could effectively degrade 59 kinds of alkanes were obtained. The AlmA gene of AQ-15 to degrade long chain paraffin oil was analyzed by combining molecular biology techniques， and it was found that 47th amino acids changed from aspartic acid （Asp，D）into glycine （Gly，G）， and enzyme activity was improved to get target of effectively degrading long chain paraffin oil， which revealed the improvement mechanism of degradation rate of Acinetobacter after ion implantation. [Conclusion] A Acinetobacter strain AQ-15 which could effectively degrade petroleum hydrocarbons was screened out.

Key words Ion implantation；Acinetobacter；Degradation rate；Degradation mechanism

石油類产品是重要的能源和工业原料，随着其使用范围的不断扩大，石油类产品的排放物对土壤生态系统结构的破坏问题也日益凸显，石油污染治理刻不容缓[1]。科研工作者提出了一系列治理石油污染的技术，包括物理、化学、生物等方式，其中，生物治理依据微生物能以烃类为唯一碳源和能源生长，将烃降解成对环境无害的产物 CO2和H2O的特点，相比物理、化学治污具有安全、效果好、成本低、处理彻底、无二次污染等优点，是一种经济效益和环境效益俱佳并且能解决复杂环境污染问题的有效治污手段[2]。……