樟树内生细菌EBS05的鉴定及其抗菌活性物质性质的研究

Identificition of Endophytic Bacteria EBS05 from Cinamonum camphra and Property of Its Antimicrobial Compound

摘要:

在形态学分类的基础上, 通过16S~23S rRNA ISR(Intergenic spacer regions)序列分析, 对樟树内生细菌EBS05进行了分类鉴定, 结果表明EBS05为枯草芽孢杆菌。测定了EBS05代谢活性物质的理化性质, 结果表明, 活性组分在λ213.5 nm处有最大光吸收峰; 在pH 5~8范围内其抗菌活性稳定, 当pH＜4.0或pH＞9.0时, 抗菌活性显著降低; 热稳定性良好, 60°C~80°C处理2 h后, 抗菌活性不变, 1′105 Pa灭菌30 min后, 抗菌活性仍然保持在65%以上; 具有较强的抗紫外线照射能力, 对蛋白酶K不敏感; 具有较好的醇溶性, 易溶于甲醇和乙醇, 不溶于乙酸乙酯、乙腈和石油醚等有机溶剂。

Abstract:

An endophytic bacterium strain EBS05 from Cinamonum camphra was identified as Bacillus subtilis by morphological taxonomy and sequence analysis of 16S~23S rRNA intergenic spacer regions. Properties of antimicrobial compound produced by EBS05 were assayed. The active compound had the maximum absorbance peak at λ213.5 nm. The antimicrobial activity was stable in solution with pH value from 5 to 8, and decreased significantly in solution with pH value less than 4.0 or more than 9.0. The antimicrobial compound had thermodynamics stability. Its activity changed a little after treated at 60°C~80°C for two hours, and compared with 65% original activity after treated at 1×105 Pa for 30 minutes. The active substance had high resistance to ultraviolet radiation and protease K. Antimicrobial compound was soluble in alcohol solution, which was easily dissolved in methanol and ethanol, but not dissolved in ethyl acetate, acetonitrile and petroleum et al.