FREQUENCY OF HORIZONTAL GENE-TRANSFER OF A LARGE CATABOLIC PLASMID (PJP4) IN SOIL
FREQUENCY OF HORIZONTAL GENE-TRANSFER OF A LARGE CATABOLIC PLASMID (PJP4) IN SOIL
复制标题
DOI：
10.1128/aem.60.11.4053-4058.1994
复制
发表时间：
1994-11-01
影响因子：
4.4
通讯作者：
SINCLAIR, NA
中科院分区：
文献类型：
--
作者：
NEILSON, JW;JOSEPHSON, KL;SINCLAIR, NA
在评估将质粒携带的降解基因从引进的生物体转移到环境中的土著生物体的生物修复潜力方面，所做的工作有限。在这里，我们证明了通过共轭的分解代谢质粒pJP 4的转移，使用模型系统与供体和受体生物。供体生物体是真养产碱菌JMP 134，受体生物体是从有毒废物站点分离的奇形多囊藻。质粒pJP 4含有抗汞基因和2，4-二氯苯氧乙酸（2，4-D）降解基因。在固体琼脂培养基上观察到供体和受体细胞（亲本细胞）的转移频率约为1/10（3），在无菌土壤中降至1/10（5）亲本细胞，最后在2，4-D改良的非无菌土壤中降至1/10（6）亲本细胞。假定的transconjugants被证实是耐汞，能够降解2，4-D，并包含一个质粒的大小可比的pJP 4。此外，我们通过PCR扩增tfdB基因证实了转移。虽然在纯培养中pJP 4的转移确实发生在高频率，但通过引入非生物（无菌土壤）和生物（非无菌土壤）胁迫，该速率显着降低。从这个模型系统的数据的评价意味着从供体生物体的质粒转移作为一种补救策略的依赖具有有限的潜力。
Limited work has been done to assess the bioremediation potential of transfer of plasmid-borne degradative genes from introduced to indigenous organisms in the environment. Here we demonstrate the transfer by conjugation of the catabolic plasmid pJP4, using a model system with donor and recipient organisms. The donor organism was Alcaligenes eutrophus JMP134 and the recipient organism was Variovarax paradoxus isolated from a toxic waste site. Plasmid pJP4 contains genes for mercury resistance and 2,4-dichlorophenoxyacetic (2,4-D) acid degradation. A transfer frequency of approximately 1/10(3) donor and recipient cells (parent cells) was observed on solid agar media, decreasing to 1/10(5) parent cells in sterile soil and finally 1/10(6) parent cells in 2,4-D-amended, nonsterile soil. Presumptive transconjugants were confirmed to be resistant to Hg, to be capable of degrading 2,4-D, and to contain a plasmid of size comparable to that of pJP4. In addition, we confirmed the transfer through PCR amplifications of the tfdB gene. Although transfer of pJP4 did occur at a high frequency in pure culture, the rate was significantly decreased by the introduction of abiotic (sterile soil) and biotic (nonsterile soil) stresses. An evaluation of the data from this model system implies that the reliance on plasmid transfer from a donor organism as a remediative strategy has limited potential.