石油烃降解菌Acinetobacter sp.5-5对正十六烷的降解特性研究
- 1. 中科院西北生态环境资源研究院
- 2. 中国科学院西北生态环境研究院
基金项目:
国际级- PY/MIT/HS-SPME技术在深层-超深层烃源岩轻烃定量及单体同位素分析中的应用研究,(42072180)
- 收稿日期:
2023-09-15
- 网络出版日期:
2023-12-12
摘要: 为探究长庆油田石油污染土壤微生物对正十六烷（石油主要成分）的降解特性，以石油污染场地土壤为菌源，旨在筛选出对正十六烷具有高效降解功能的菌株，并采用盐碱化模式，实现耐盐碱降解，并探讨降解动力学特征及相关代谢机制。通过形态特征、革兰氏染色、生化理化试验以及16s rDNA序列分析确定该菌株为不动杆菌(Acinetobacter sp)。通过抗逆性实验（14 d）探究了菌株Acinetobacter sp.5-5的最佳降解条件，结果表明正十六烷浓度为0.5% (V/V)、盐度为0.5%，pH为7.0，在此条件下石油烃降解菌对正十六烷的总降解率高达99.24%，且两天内完成快速降解（82.13 %）。其次基于零级、准一级、准二级动力学模型对正十六烷降解过程中的动力学进行研究，结果表明准一级模型对正十六烷的基质降解过程拟合效果最佳。结合培养液酸碱度和降解产物谱图分析，初步解析正十六烷在该微生物降解体系中的降解途径为断链和产酸。研究表明石油烃降解菌对正十六烷具有较高的降解潜力，并具有较好的耐盐碱特性，有望在石油污染盐碱化土壤修复中广泛应用。
Study on the degradation characteristics of n-hexadecane by petroleum hydrocarbon-degrading bacteria Acinetobacter sp.5-5
- Received Date:
2023-09-15
- Available Online:
2023-12-12
Abstract: To investigate the degradation characteristics of n-hexadecane, a major component of petroleum, by microorganisms isolated from petroleum-contaminated soil in the Changqing oilfield, we employed petroleum-contaminated soil as the source of bacteria. Our objectives were to isolate strains with highly efficient n-hexadecane degradation capabilities, implement a salinization approach to achieve salinity-resistant degradation, and elucidate the kinetics and associated metabolic mechanisms of degradation. Through morphological characterization, Gram staining, biochemical and physicochemical tests, as well as 16S rDNA sequence analysis, we identified the isolated strain as Acinetobacter sp.5-5. The optimal degradation conditions for Acinetobacter sp.5-5 were determined through a resistance experiment spanning 14 days. It was found that, under specific conditions of n-hexadecane concentration (0.5% (V/V)), salinity (0.5%), and pH (7.0), the petroleum hydrocarbon-degrading bacteria achieved a remarkable total degradation of n-hexadecane, reaching 99.24%, with rapid degradation completed within two days (82.13%). Subsequently, the kinetics of n-hexadecane degradation were explored using zero-, quasi-primary, and quasi-secondary kinetic models. The results revealed that the quasi-primary model provided the best fit for describing the degradation process of n-hexadecane. Furthermore, in conjunction with the analysis of culture solution pH and degradation product profiles, our preliminary assessment of the n-hexadecane degradation pathway within this microbial degradation system indicated a process involving chain cleavage and acid production. This study underscores the high degradation potential of petroleum hydrocarbon-degrading bacteria, including their resilience to saline and alkaline conditions, particularly in the context of n-hexadecane. These findings hold promise for their widespread application in the remediation of salinized petroleum-contaminated soils.
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