Abstract

Members of the Raoultella planticola species isolated from soils contaminated with chemical waste were able to use 2,4-dichlorophenoxyacetic/2,4,5-trichlorophenoxyacetic acid as the sole source of carbon and energy. It was found that cells of strains 33-4ch, 36D, and 36T contained plasmids that were designated as pRP33-4ch, pRP36D and pRP36T, respectively. Restriction fragment length polymorphism (RFLP) analysis showed that pRP33-4ch and pRP36T were probably the same plasmid, while pRP36D contained additional fragments in the restriction profiles. Plasmid elimination showed that the genes for the degradation of chlorophenoxyacetic acids have extrachromosomal localization. Polymerase chain reaction (PCR) demonstrated the absence in the genomes of the studied strains of known initiation genes (tfdA and tftA) for the conversion of chlorophenoxyacetic acids. The identified intermediate metabolites (chlorophenoxyacetic and phenoxyacetic acids and 2-keto-3-methylmuconic semialdehyde) indicated that the strains 33-4ch, 36D, and 36T perform complete dechlorination of the aromatic ring of the substrate with its subsequent meta-cleavage.

中文翻译：

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Raoultella属细菌的氯苯氧乙酸降解质粒

摘要

从被化学废物污染的土壤中分离出来的Raoultella planticola物种成员能够使用 2,4-二氯苯氧乙酸/2,4,5-三氯苯氧乙酸作为碳和能量的唯一来源。发现菌株33-4ch、36D和36T的细胞含有分别命名为pRP33-4ch、pRP36D和pRP36T的质粒。限制性片段长度多态性 (RFLP) 分析表明 pRP33-4ch 和 pRP36T 可能是相同的质粒，而 pRP36D 在限制性配置文件中包含额外的片段。质粒消除表明用于降解氯苯氧乙酸的基因具有染色体外定位。聚合酶链反应 (PCR) 证明所研究菌株的基因组中不存在已知起始基因 ( tfdA和tftA ) 用于转化氯苯氧乙酸。鉴定的中间代谢物（氯苯氧乙酸和苯氧乙酸和 2-keto-3-methylmuconic semialdehyde）表明菌株 33-4ch、36D 和 36T 对底物的芳环进行完全脱氯，随后进行间位裂解。