Bioresource Center, Japan Collection of Microorganisms (BRC-JCM), Riken, 2–1 Hirosawa, Wako, Saitama 351–0198, Japan.
Microbes Environ. 2010;25(4):253-65. doi: 10.1264/jsme2.me10155.
Over the past few decades, degradative plasmids have been isolated from bacteria capable of degrading a variety of both natural and man-made compounds. Degradative plasmids belonging to three incompatibility (Inc) groups in Pseudomonas (IncP-1, P-7, and P-9) have been well studied in terms of their replication, maintenance, and capacity for conjugative transfer. The host ranges of these plasmids are determined by replication or conjugative transfer systems. The host range of IncP-1 is broad, that of IncP-9 is intermediate, and that of IncP-7 is narrow. To understand the behavior of these plasmids and their hosts in various environments, the survivability of inocula, stability or transferability, and efficiency of biodegradation in environments and microcosms have been monitored. The biodegradation and plasmid transfer in various environments have been observed for all three groups, although the kinds of transconjugants differed with the Inc groups. In some cases, the deletion and amplification of catabolic genes acted to reduce the production of toxic catabolic intermediates, or to increase the activity on a particular catabolic pathway. The combination of degradative genes, the plasmid backbone of each Inc group, and the host of the plasmids is key to the degraders adapting to various hosts or to heterogeneous environments.
在过去的几十年中，已经从能够降解各种天然和人工化合物的细菌中分离出了降解质粒。在 Pseudomonas 中属于三个不相容性 (Inc) 组的降解质粒（IncP-1、P-7 和 P-9）在复制、维持和可进行接合转移方面得到了很好的研究。这些质粒的宿主范围由复制或接合转移系统决定。IncP-1 的宿主范围很广，IncP-9 的宿主范围中等，IncP-7 的宿主范围较窄。为了了解这些质粒及其宿主在各种环境中的行为，已经监测了接种物的存活率、稳定性或可转移性，以及在环境和微宇宙中的生物降解效率。已经观察到所有三组在各种环境中的生物降解和质粒转移，尽管与 Inc 组不同的是转导子的种类。在某些情况下，代谢基因的缺失和扩增可减少有毒代谢中间产物的产生，或增加特定代谢途径的活性。降解基因、每个 Inc 组的质粒骨架和质粒的宿主的组合是适应各种宿主或异质环境的关键。
