Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Powai, 400 076 Mumbai, India.
Arch Microbiol. 2013 Aug;195(8):521-35. doi: 10.1007/s00203-013-0903-9. Epub 2013 Jun 2.
Pseudomonas sp. strains C4, C5 and C6 degrade carbaryl (1-naphthyl N-methylcarbamate) via 1-naphthol, 1,2-dihydroxynaphthalene, salicylate and gentisate. Carbon source-dependent metabolic studies suggest that enzymes responsible for carbaryl degradation are probably organized into 'upper' (carbaryl to salicylate), 'middle' (salicylate to gentisate) and 'lower' (gentisate to TCA cycle) pathway. Carbaryl and 1-naphthol were found to induce all carbaryl pathway enzymes, while salicylate and gentisate induce middle and lower pathway enzymes. The strains were found to harbor plasmid(s), and carbaryl degradation property was found to be stable. Genes encoding enzymes of the degradative pathway such as 1-naphthol 2-hydroxylase, salicylaldehyde dehydrogenase, salicylate 5-hydroxylase and gentisate 1,2-dioxygenase were amplified from chromosomal DNA of these strains. The gene-specific PCR products were sequenced from strain C6, and phylogenetic tree was constructed. Southern hybridization and PCR analysis using gel eluted DNA as template supported the presence of pathway genes onto the chromosome and not on the plasmid(s).
假单胞菌菌株 C4、C5 和 C6 通过 1-萘酚、1,2-二羟基萘、水杨酸和龙胆酸降解西维因（1-萘基 N-甲基氨基甲酸酯）。碳源依赖性代谢研究表明，负责西维因降解的酶可能组织成“上”（西维因到水杨酸）、“中”（水杨酸到龙胆酸）和“下”（龙胆酸到 TCA 循环）途径。发现西维因和 1-萘酚诱导所有西维因途径的酶，而水杨酸和龙胆酸诱导中、下途径的酶。这些菌株被发现含有质粒，并且西维因降解特性稳定。从这些菌株的染色体 DNA 中扩增了编码降解途径酶的基因，如 1-萘酚 2-羟化酶、水杨醛脱氢酶、水杨酸 5-羟化酶和龙胆酸 1,2-双加氧酶。从菌株 C6 中对基因特异性 PCR 产物进行测序，并构建系统发育树。Southern 杂交和使用凝胶洗脱 DNA 作为模板的 PCR 分析支持途径基因位于染色体上而不是质粒上。
