Klapwijk P M, Hooykaas P J, Kester H C, Schilperoort R A, RORSCH A
J Gen Microbiol. 1976 Sep;96(1):155-63. doi: 10.1099/00221287-96-1-155.
Using an enrichment procedure, mutant strains of Agrobacterium tumefaciens were isolated that lacked the ability to utilize octopine as a nitrogen source. Of 55 such isolates, 44 were unable to utilize several amino acids; the remaining 11 strains were altered solely in their ability to utilize octopine, octopinic acid and lysopine. It is concluded that only the latter were plasmid mutations. Among them, there was a high, but no absolute, correlation with avirulence. All strains contained the T1 plasmid. All virulent strains showed active transport of octopine when they had previously been grown in medium containing octopine, whereas the avirulent strains failed to show such transport. All the virulent mutants induced tumours containing octopine. The results are discussed in relation to the hypothesis that the genes which code for the octopine synthesizing enzymes in the tumour are of bacterial origin.
采用富集培养法，分离出了缺乏利用章鱼碱作为氮源能力的根癌土壤杆菌突变菌株。在55个这样的分离株中，44个无法利用几种氨基酸；其余11个菌株仅在利用章鱼碱、章鱼氨酸和溶菌碱的能力上发生了改变。结论是只有后者是质粒突变。其中，与无毒力之间存在高度但并非绝对的相关性。所有菌株都含有Ti质粒。所有有毒力的菌株在先前生长于含章鱼碱的培养基中时，都表现出章鱼碱的主动转运，而无毒力的菌株则未表现出这种转运。所有有毒力的突变体都诱导出含有章鱼碱的肿瘤。结合肿瘤中编码章鱼碱合成酶的基因来源于细菌这一假说对结果进行了讨论。
