Department of Plant Pathology, University of California, Berkeley, California 94720.
Appl Environ Microbiol. 1988 May;54(5):1222-9. doi: 10.1128/aem.54.5.1222-1229.1988.
Erwinia carotovora subsp. betavasculorum strains produced a bactericidal antibiotic in vitro that inhibited a wide spectrum of gram-negative and gram-positive bacteria. The optimum temperature for production was 24 degrees C, and the addition of glycerol to culture media enhanced antibiotic production. Antibiotic production by these strains in the infection court of potato was the principal determinant enabling it to gain ascendancy over competing antibiotic-sensitive Erwinia carotovora subsp. carotovora strains. There was a complete correlation between antibiotic production by E. carotovora subsp. betavasculorum in vitro and inhibition of competing E. carotovora subsp. carotovora strains in planta. Inhibition of the latter by the former was apparent after 10 h of incubation in potato tuber wounds. Population densities of sensitive E. carotovora subsp. carotovora strains in mixed potato tuber infections with E. carotovora subsp. betavasculorum were approximately 10-fold lower after 48 h of incubation than in corresponding single sensitive strain infections. E. carotovora subsp. carotovora were not inhibited in tuber infections that were incubated anaerobically. This correlated with the absence of antibiotic production during anaerobic incubation in vitro. Antibiotic-resistant strains of E. carotovora subsp. carotovora were not inhibited in planta or in vitro by E. carotovora subsp. betavasculorum. Moreover, isogenic antibiotic-negative (Ant) mutant E. carotovora subsp. betavasculorum strains were not inhibitory to sensitive E. carotovora subsp. carotovora strains in tuber infections.
胡萝卜软腐果胶杆菌亚种贝塔瓦索拉菌株在体外产生一种杀菌抗生素，能抑制广泛的革兰氏阴性和革兰氏阳性细菌。最适生产温度为 24°C，向培养基中添加甘油可增强抗生素的产生。这些菌株在感染的马铃薯块茎中产生抗生素，是其战胜竞争的抗生素敏感胡萝卜软腐果胶杆菌亚种胡萝卜软腐亚种的主要决定因素。胡萝卜软腐果胶杆菌亚种贝塔瓦索拉在体外产生抗生素的能力与在体内抑制竞争的胡萝卜软腐果胶杆菌亚种胡萝卜软腐亚种的能力之间存在完全相关性。在马铃薯块茎伤口中培养 10 小时后，前者对后者的抑制作用明显。在与胡萝卜软腐果胶杆菌亚种贝塔瓦索拉混合感染的马铃薯块茎中，敏感的胡萝卜软腐果胶杆菌亚种胡萝卜软腐亚种的种群密度在 48 小时的培养后比在相应的单一敏感菌株感染中降低了约 10 倍。在厌氧条件下培养的块茎感染中，胡萝卜软腐果胶杆菌亚种胡萝卜软腐亚种不会被抑制。这与体外厌氧培养时没有抗生素产生有关。在体内或体外，胡萝卜软腐果胶杆菌亚种胡萝卜软腐亚种的抗生素抗性菌株都不会被胡萝卜软腐果胶杆菌亚种贝塔瓦索拉抑制。此外，同源的抗生素阴性（Ant）突变胡萝卜软腐果胶杆菌亚种贝塔瓦索拉菌株在马铃薯块茎感染中对敏感的胡萝卜软腐果胶杆菌亚种胡萝卜软腐亚种菌株没有抑制作用。
