以印度洋深层海水,用柴油和石油作为混合碳源经富集培养、分离获得一株具有很强的柴油降解能力的菌株P40.菌株P40革兰氏染色阴性,接触酶和氧化酶为阳性,能还原硝酸盐,不能还原亚硝酸盐.16S rDNA B lastn结果表明其与Alcanivorax dieselo...以印度洋深层海水,用柴油和石油作为混合碳源经富集培养、分离获得一株具有很强的柴油降解能力的菌株P40.菌株P40革兰氏染色阴性,接触酶和氧化酶为阳性,能还原硝酸盐,不能还原亚硝酸盐.16S rDNA B lastn结果表明其与Alcanivorax dieseloleiB-5T(柴油食烷菌)及A.dieseloleiNO1A具有最高相似性,均为99.8%.菌株P40的gyrB序列与A.dieseloleiNO1A同源性也高达99.2%,而与A.dieseloleiB-5T只有86.9%.此外,从菌株P40中克隆到两个烷烃羟化酶alkB基因片断,分别命名为P40a-lkB1和P40a-lkB2.其中P40a-lkB1与报道的A.dieseloleiB-5T中的alkB同源性较高,达96.3%,而与同为深海来源的菌株NO1A的alkB的同源性更是达100%,P40a-lkB2则与A.borkum ensisSK2T(泊库岛食烷菌)的alkB1同源性最高,但仅为65%.展开更多
【目的】食烷菌是海洋烃类降解优势菌,其烷烃代谢调控机制有待深入研究。本研究拟从食烷菌转录和翻译水平上认识烷烃降解的调控过程。【方法】分别以乙酸和正十六烷(C16)为唯一碳源与能源,获取柴油食烷菌(Alcanivorax dieselolei)B5菌...【目的】食烷菌是海洋烃类降解优势菌,其烷烃代谢调控机制有待深入研究。本研究拟从食烷菌转录和翻译水平上认识烷烃降解的调控过程。【方法】分别以乙酸和正十六烷(C16)为唯一碳源与能源,获取柴油食烷菌(Alcanivorax dieselolei)B5菌株的转录组和翻译组数据,并整合数据计算得到该菌在2种碳源培养条件下基因的翻译效率。采用基因本体论(gene ontology,GO)和京都基因和基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)对差异翻译和翻译效率基因进行功能和代谢通路注释。【结果】当以C16为唯一碳源与能源时,B5菌株烷烃代谢途径的关键基因在转录与翻译水平均大量提升,包括烷烃单加氧酶、细胞色素P450氧化酶、醇脱氢酶和醛脱氢酶等。KEGG富集结果表明,翻译水平显著上调基因参与了肽聚糖生物合成、脂肪酸降解、氯代烷烃降解、氧化磷酸化和生物膜形成等通路;翻译效率差异基因主要富集在铁载体非核糖体肽的生物合成、氧化磷酸化和不饱和脂肪酸的生物合成等途径。通过转录组和翻译组学的联合分析显示,为了适应烷烃氧化,B5有效地协调了转录与翻译过程;B5在2种碳源培养条件下基因表达水平与翻译效率均呈现负相关性;全局蛋白调节因子CsrA和sRNAs参与的转录后调控可能导致了烷烃代谢相关基因的翻译效率差异。【结论】转录组和翻译组数据的联合分析表明转录后调控参与了食烷菌的烷烃代谢过程,本研究为进一步探究食烷菌烷烃代谢的转录后调控机制奠定了基础。展开更多
In order to better understand the effects of biostimulation and bioaugmentation processes on a marine microbial community, three different mesocosm experiments were planned. Natural seawater（10.000 L） was artificial...In order to better understand the effects of biostimulation and bioaugmentation processes on a marine microbial community, three different mesocosm experiments were planned. Natural seawater（10.000 L） was artificially polluted with crude oil（1 L） and（1） inorganic nutrients（Biostimulating Mesocosm, BM）,（2） inorganic nutrients and an inoculum of Alcanivorax borkumensis SK2（Single Bioaugmentation Mesocosm, SBM）,（3） inorganic nutrients and inoculums of A. borkumensis SK2 and Thalassolituus oleivorans MIL-1（Consortium Bioaugmentation Mesocosm, CBM）. During the experimental period（20 days）, samples were taken from each mesocosm and the community structure was analyzed by PCR–DGGE. The 16 S r RNA gene DGGE banding patterns and sequence analysis demonstrated that biostimulation had the lowest effect on microbial biodiversity in the mesocosms; however, the biodiversity of the marine microbial community dramatically decreased in the CBM（Shannon index was 0.6 in T3）. The community structures among the three mesocosms were also markedly different,and major bacteria derived from DGGE bands were related to uncultured Gamma Proteobacteria. The biodegradation results show that the Single Bioaugmentation Mesocosm（SBM） system had the highest percentage of degradation（95%） in comparison to the BM mesocosm（80%） and CBM（70%）.展开更多
文摘【目的】食烷菌是海洋烃类降解优势菌,其烷烃代谢调控机制有待深入研究。本研究拟从食烷菌转录和翻译水平上认识烷烃降解的调控过程。【方法】分别以乙酸和正十六烷(C16)为唯一碳源与能源,获取柴油食烷菌(Alcanivorax dieselolei)B5菌株的转录组和翻译组数据,并整合数据计算得到该菌在2种碳源培养条件下基因的翻译效率。采用基因本体论(gene ontology,GO)和京都基因和基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)对差异翻译和翻译效率基因进行功能和代谢通路注释。【结果】当以C16为唯一碳源与能源时,B5菌株烷烃代谢途径的关键基因在转录与翻译水平均大量提升,包括烷烃单加氧酶、细胞色素P450氧化酶、醇脱氢酶和醛脱氢酶等。KEGG富集结果表明,翻译水平显著上调基因参与了肽聚糖生物合成、脂肪酸降解、氯代烷烃降解、氧化磷酸化和生物膜形成等通路;翻译效率差异基因主要富集在铁载体非核糖体肽的生物合成、氧化磷酸化和不饱和脂肪酸的生物合成等途径。通过转录组和翻译组学的联合分析显示,为了适应烷烃氧化,B5有效地协调了转录与翻译过程;B5在2种碳源培养条件下基因表达水平与翻译效率均呈现负相关性;全局蛋白调节因子CsrA和sRNAs参与的转录后调控可能导致了烷烃代谢相关基因的翻译效率差异。【结论】转录组和翻译组数据的联合分析表明转录后调控参与了食烷菌的烷烃代谢过程,本研究为进一步探究食烷菌烷烃代谢的转录后调控机制奠定了基础。
基金supported by the Shahid Bahonar University of Kerman and grants from EC Project “Unraveling and exploiting Mediterranean Sea microbial diversity and ecology for Xenobiotics' and pollutants' clean up” (No. ULIXES-FP7KBBE-2010-3.5-03)
文摘In order to better understand the effects of biostimulation and bioaugmentation processes on a marine microbial community, three different mesocosm experiments were planned. Natural seawater（10.000 L） was artificially polluted with crude oil（1 L） and（1） inorganic nutrients（Biostimulating Mesocosm, BM）,（2） inorganic nutrients and an inoculum of Alcanivorax borkumensis SK2（Single Bioaugmentation Mesocosm, SBM）,（3） inorganic nutrients and inoculums of A. borkumensis SK2 and Thalassolituus oleivorans MIL-1（Consortium Bioaugmentation Mesocosm, CBM）. During the experimental period（20 days）, samples were taken from each mesocosm and the community structure was analyzed by PCR–DGGE. The 16 S r RNA gene DGGE banding patterns and sequence analysis demonstrated that biostimulation had the lowest effect on microbial biodiversity in the mesocosms; however, the biodiversity of the marine microbial community dramatically decreased in the CBM（Shannon index was 0.6 in T3）. The community structures among the three mesocosms were also markedly different,and major bacteria derived from DGGE bands were related to uncultured Gamma Proteobacteria. The biodegradation results show that the Single Bioaugmentation Mesocosm（SBM） system had the highest percentage of degradation（95%） in comparison to the BM mesocosm（80%） and CBM（70%）.
