烟草青枯病菌内生拮抗菌株HN3的鉴定与高产抗菌物质的培养基优化

通过稀释涂布平板法从感染青枯病的烟草‘K326’侧根内分离到大量内生菌。以烟草青枯病菌为指示菌，采用对峙培养法筛选出有拮抗活性的内生细菌13株。根据抑菌活性试验，从中选取一株抑菌效果最好的内生拮抗细菌HN3分别进行16S rDNA序列鉴定、BIOLOG微生物自动鉴定系统鉴定和系统发育学分析，结果表明，HN3属于假单胞杆菌(Pseudomonas)。试验还初步确定了有利于增强HN3抑菌活性的碳源、氮源和无机盐，并通过L9(34)正交试验优化了上述3种营养成分的用量。结果表明，最佳培养基成分为：葡萄糖12 g、尿素0.32 g、磷酸氢二钾3 g，优化后菌株HN3的抑菌活性增加了35.7%。

Identification and optimization for high production of antimicrobial substance growth medium by an endophytic strain HN3

Abstract: Through the dilution method, 13 antagonistic endophytic bacterium were isolated from the infected tabacoo laterals. Among these antagonistic bacteria HN3 was exhibited the highest antagonistic activity against Ralstonia solanacarum. HN3 has been identified to be Pseudomonas with BIOLOG automatic microbiology analysis system and 16S rDNA determination and analysis. For the high production of antimicrobial substance growth. the medium composition were optimized by single factor carbon﹑nitrogen﹑inorganic and orthogonal experiments L9(34). As a result, The optium medium were glucose 12g、carbamide 0.32g and potassium phosphate 3g. after the optimization, antagonistic activity of the strain HN3 enhances 35.7%.