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›› 2007, Vol. 7 ›› Issue (1): 113-118.

• 生化工程专栏 • 上一篇    下一篇

Klebsiella sp. LSSE-H2的咔唑降解

黄杰勋,熊小超,李望良,李信,邢建民,刘会洲   

  1. 中国科学院过程工程研究所分离科学与工程实验室
  • 出版日期:2007-02-20 发布日期:2007-02-20

Carbazole Degradation by Klebsiella sp. LSSE-H2

HUANG Jie-xun,XIONG Xiao-chao,LI Wang-liang,LI Xin,XING Jian-min,LIU Hui-zhou   

  1. Laboratory of Separation Science and Engineering, Institute of Process Engineering) Chinese Academy of Sciences
  • Online:2007-02-20 Published:2007-02-20

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摘要： 从染料污染的土壤中分离出1株新的咔唑降解菌LSSE-H2，能以咔唑作为唯一的碳源、氮源和能源. 依据16S rRNA基因序列的系统发育分析将该菌鉴定为Klebsiella sp. 该菌在30℃、以咔唑为唯一的碳源、氮源的选择性培养基(CNFM)中，经过56 h可将浓度为12 mmol/L的咔唑几乎完全降解，在浓度为16 mmol/L的咔唑中也同样表现出高的咔唑降解活性. 对比分析不同营养成分培养基中对咔唑的降解情况表明，LSSE-H2可能存在独特的咔唑降解活性表达调控模式. 按照已公布的car基因簇序列设计同源引物，PCR扩增出LSSE-H2的包含5个咔唑降解基因的car基因簇片断，测序结果表明，咔唑降解基因高度保守，与Sphingomonas sp. KA1和Sphingomonas sp. GTIN11相应的咔唑基因的同源性都达到100%，只在基因簇的非编码区上发现少数碱基不同. 对比研究表明，LSSE-H2, KA1和GTIN11中car基因簇的起源可能相同，并能在不同的细菌之间水平转移.

关键词: 脱氮, 咔唑, 生物降解, 基因簇, Klebsiella

Abstract: A novel bacterial strain LSSE-H2 isolated from dye-contaminated soil could use carbazole as the sole source of carbon, nitrogen and energy. Based on the phylogenetic analysis of the 16S rRNA gene, this strain was identified as Klebsiella sp. At 30℃, strain LSSE-H2 could almost completely degrade 12 mmol/L carbazole as the sole source of carbon, nitrogen and energy in carbon- and nitrogen-free media (CNFM) after 56 h of cultivation. High carbazole degradation activity was also observed in 16 mmol/L carbazole. Analysis of the carbazole degradation in different culture media indicated that LSSE-H2 possessed unique regulation mode of the expression of carbazole-degrading capacity. Using two sharing primers for Sphingomonas sp. KA1 and Sphingomonas sp. GTIN11, the carbazole degradation gene cluster containing five car genes was amplified by polymerase chain reaction (PCR), and these genes were 100% homologous to KA1 and GTIN11 genes except several different points in the non-coding region of the gene cluster. It may be deduced that the car gene clusters in LSSE-H2, KA1 and GTIN11 have the same origin, and could laterally transfer between different bacteria.

Key words: denitrogenation, carbazole, biodegradation, gene cluster, Klebsiella