Kulakova A N, Boronin A M
Mikrobiologiia. 1989 Mar-Apr;58(2):298-304.
Most of the known naphthalene biodegradation plasmids determine the process of naphthalene degradation via salicylate and catechol using the meta pathway of catechol degradation. However, Pseudomonas putida strains with plasmids pBS2, pBS216, pBS217 and NPL-1 exert no activity of the enzymes involved in the meta pathway of catechol degradation. When 2-methylnaphthalene was added to the medium as a sole carbon source, mutants growing on this compound were isolated in the strains with the studied plasmids. Plasmid localization of the mutations was established using conjugation transfer as well as by obtaining spontaneous variants that had lost the ability to grow on 2-methylnaphthalene; the respective plasmid mutants were referred to as pBS101, pBS102, pBS103 and pBS105. The strains with the mutant plasmids were tested for the activity of the key enzymes involved in naphthalene catabolism and the activity of catechol-2,3-dioxygenase was found. The data allow one to arrive at the conclusion that plasmids pBS2, pBS216, pBS217 and NPL-1 contain silent genes for the meta pathway of catechol degradation, which are activated by the respective mutations.
大多数已知的萘生物降解质粒通过邻苯二酚降解的间位途径，决定了萘经水杨酸和邻苯二酚降解的过程。然而，携带质粒pBS2、pBS216、pBS217和NPL-1的恶臭假单胞菌菌株，在邻苯二酚降解的间位途径中所涉及的酶没有活性。当将2-甲基萘作为唯一碳源添加到培养基中时，在携带所研究质粒的菌株中分离出了能利用该化合物生长的突变体。利用接合转移以及通过获得失去在2-甲基萘上生长能力的自发变体，确定了突变的质粒定位；相应的质粒突变体分别称为pBS101、pBS102、pBS103和pBS105。对携带突变体质粒的菌株进行了萘分解代谢中关键酶活性的测试，并发现了邻苯二酚-2,3-双加氧酶的活性。这些数据使人们得出结论，质粒pBS2、pBS216、pBS217和NPL-1含有邻苯二酚降解间位途径的沉默基因，这些基因通过各自的突变被激活。
