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从不同甜瓜果实表面可分离到在LB培养基上生长迅速、菌落形态呈明显差异的4类革兰氏染色阳性细菌。经过生理生化指标的鉴定、菌株间16S rDNA序列和部分特异性基因序列扩增以及种间遗传距离分析,将这4类芽孢杆菌分别鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)和枯草芽孢杆菌(Bacillus subtilis)的3个形态变种。这些芽孢杆菌经继代培养20代后,仍能保持稳定的菌落形态和对灰葡萄孢(Botrytis cinerea)、链格孢(Alternaria alternata)、尖孢镰刀菌(Fusari-um oxysporum)、黑曲霉(Aspegillus niger)和粉红单端孢(Trichothecium roseum)等8种果蔬采后病原真菌显著且广谱的拮抗作用。结果表明,甜瓜果实表面广泛分布着具有拮抗性能的枯草芽孢杆菌和其近缘种解淀粉芽孢杆菌,可通过特定培养条件下(LB培养基上37℃培养48 h)单菌落的生长速度和菌落外观形态特征快速分离并鉴别它们的类群,为开发甜瓜果实采后保鲜制剂提供理论依据。
From the different melon fruit surface can be isolated on the LB medium rapid growth, colony morphology was significantly different from the 4 types of Gram-positive bacteria. Through the identification of physiological and biochemical indicators, 16S rDNA sequence and partial sequence-specific gene sequence amplification and interspecific genetic distance analysis, the four Bacillus strains were identified as Bacillus amyloliquefaciens (Bacillus amyloliquefaciens) and Bacillus subtilis) three morphological variants. After 20 generations of subculture, these Bacillus still maintain stable colony morphology and inhibit colonization of Botrytis cinerea, Alternaria alternata, Fusari-um oxysporum, Aspergillus niger Aspegillus niger and Trichothecium roseum. The results showed that the antagonistic Bacillus subtilis and its related species Bacillus amyloliquefaciens were broadly distributed on the surface of muskmelon fruits. The growth rate of single colonies and the number of colonies of Bacillus subtilis under specific culture conditions (48 ℃ for 48 h on LB medium) The appearance morphological characteristics of rapid separation and identification of their taxa, for the development of melon fruit postharvest preservation preparations provide a theoretical basis.