Wall J D, Weaver P F, Gest H
Arch Microbiol. 1975 Nov 7;105(3):217-24. doi: 10.1007/BF00447140.
Thirty-three wild type strains of Rhodopseudomonas capsulata were examined for ability to engage in genetic recombination through mediation by "gene transfer agent" (GTA) particles. The genetic exchange assays were based on capacity of strains to produce or receive GTA required for restoration of photosynthetic growth competence to a non-photosynthetic "white" mutant or for acquisition of resistance to rifampicin. A majority of the strains could either produce or receive GTA, and it was demonstrated that the agent is species specific. Possible relations between GTA and bacteriophages or bacteriocins were investigated. Sixteen types of virulent phages active on Rps. capsulata were isolated and their host ranges determined. Tests for transduction by the phages gave uniformly negative results. The viruses showed strict species specificity, but there was no apparent correlation between capacity of the Rps. capsulata strains to donate or receive GTA and susceptibility to the phages. A comparable survey disclosed that most of the bacterial strains were sensitive to or capable of producing bacteriocins; the latter also appear to be unrelated to GTA activity. The collection of bacterial strains was also screened for detection of lysogenic properties. None of the isolates is a "true" lysogen, but phages were detected in cultures of two strains, which may be "phage carriers" or pseudolysogens.
对33株野生型荚膜红假单胞菌进行了检测，以确定它们通过“基因转移因子”（GTA）颗粒介导进行基因重组的能力。基因交换试验基于菌株产生或接收GTA的能力，GTA是恢复非光合“白色”突变体光合生长能力或获得对利福平抗性所必需的。大多数菌株能够产生或接收GTA，并且证明该因子具有物种特异性。研究了GTA与噬菌体或细菌素之间的可能关系。分离出16种对荚膜红假单胞菌有活性的烈性噬菌体，并确定了它们的宿主范围。噬菌体转导试验结果均为阴性。这些病毒表现出严格的物种特异性，但荚膜红假单胞菌菌株产生或接收GTA的能力与对噬菌体的敏感性之间没有明显的相关性。一项类似的调查显示，大多数细菌菌株对细菌素敏感或能够产生细菌素；后者似乎也与GTA活性无关。还对该细菌菌株的集合进行了筛选，以检测溶原性。没有一个分离株是“真正的”溶原菌，但在两个菌株的培养物中检测到了噬菌体，这两个菌株可能是“噬菌体携带者”或假溶原菌。
