高效耐盐柴油降解菌的筛

发布时间：2018-06-04 20:23

本文选题：不动杆菌 + 柴油　；参考：《中国环境科学》2017年11期

【摘要】：在辽河口湿地油田石油污染土壤中分离到一株耐盐柴油高效降解菌株L7,经过形态学观察、16S r RNA基因序列分析鉴定菌株L7属于不动杆菌属(Acinetobacter).该菌株能够以柴油、十五烷、十六烷、十七烷、十八烷、十九烷、二十烷和二十二烷为唯一碳源和能源生长.在柴油无机盐培养基中,菌株的最适生长温度为30°C,最适pH值为7.0,菌株L7在pH 6.0~9.0,盐度范围为3%以内都可以生长.与其他的菌株相比较,菌株L7在柴油中生长更加迅速,在最适培养条件下培养4d后菌株的OD600nm就可以达到4.0,通过紫外分光光度法测定培养5d后,柴油的降解效率为61.5%.通过对菌株L7的全基因组测序和分析,在基因组上找到一个烷烃羟化酶基因alk B,将基因克隆到p ME6032质粒上,并电转至不依赖柴油生长的恶臭假单胞菌KT2440中,含有该质粒的KT2440菌株能够在柴油无机盐培养基中生长.GC-MS检测确定了菌株L7及其alk B基因对饱和烷烃的降解能力.推测菌株L7中烷烃降解途径为末端氧化途径,是由烷烃羟化酶催化反应生成相应的醇,最终通过β-氧化反应实现完全矿化.
[Abstract]:A strain L7 was isolated from oil-contaminated soil of Liaohekou Wetland Oilfield. The strain L7 was identified as Acinetobacter by morphological observation and sequence analysis of 16s r RNA gene. The strain can grow with diesel, pentadecane, hexadecane, heptadecane, octadecane, eicosane and 22 alkane as the sole carbon source and energy source. In diesel-inorganic salt medium, the optimum growth temperature was 30 掳C, the optimum pH value was 7.0, the strain L7 could grow within 3% salinity and pH 6.0. Compared with other strains, strain L7 grew more rapidly in diesel oil. The OD600nm of strain L7 could reach 4.0 after 4 d culture under the optimum culture conditions. The degradation efficiency of diesel oil was 61.5% after 5 days of cultivation by UV spectrophotometry. By sequencing and analyzing the whole genome of strain L7, an alkane hydroxylase gene alk B was found in the genome. The gene was cloned into p ME6032 plasmid and transferred to KT2440 of Pseudomonas oxysporum that did not depend on diesel oil growth. The KT2440 strain containing the plasmid was able to grow in diesel inorganic salt medium. GC-MS analysis confirmed the ability of the strain L7 and its alk B gene to degrade saturated alkanes. It is inferred that the degradation pathway of alkanes in strain L7 is the terminal oxidation pathway, which is catalyzed by alkane hydroxylase to produce corresponding alcohols, and finally realizes the complete mineralization by 尾 -oxidation reaction.
【作者单位】：中国海洋大学环境科学与工程学院海洋环境与生态教育部重点实验室;青岛农业大学生命科学学院;
【基金】：国家水体污染控制与治理科技重大专项(2013ZX07202-007)
【分类号】：X172

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