一株酸枣内生菌的鉴定及其抗菌活性物质的初步分离

为了从酸枣中筛选出内生菌并分析其代谢产物中的活性成分,用于开发和生产药物,该研究通过组织块分离法和划线分离法,从陕北野生酸枣植株体内分离得到内生菌,采用平板对峙法测定其对7株供试指示菌的抗菌活性,以心神宁片提取液为对照,对各拮抗菌株的发酵液进行薄层层析和高效液相色谱分析。结果表明:从野生酸枣中共分离得到121株内生菌,其中内生细菌49株,内生放线菌6株,内生真菌66株;通过抗菌试验,发现54株内生菌(细菌33株,真菌21株)对1～7种指示菌具有抗菌活性,占分离菌株总菌数的44.63%,其中A-04、A-05、B-03、C-03、C-06和D-04共6株菌株的抗菌谱较广,对7种供试指示菌均具有抑菌活性;薄层层析检测结果显示菌株B-03发酵产物在R_f值为0.46处有与酸枣提取液层析带迁移率相同的显色带,液相色谱分析结果显示其属于黄酮类物质;通过16S rRNA基因序列分析结果显示菌株B-03与Bacillus axarquiensis的相似性为99%。菌株B-03能发酵产生黄酮类或产生与黄酮类类似的化合物,表明酸枣内生菌具有合成黄酮类药物的潜力。

Identification of an endophytic strain from Ziziphus jujube and preliminary separation of its antimicrobial active substances

The purpose of this study was to identify endophytic strains from Ziziphus jujube and analyze the active components of their metabolites for the development and production of drugs. Wild Ziziphus jujube plants from North Shaanxi were adopted as experimental materials, and endophyte strains were isolated by approaches of tissue separation and streak plate, then they were screened and tested on the bacteriostatic activity by adopting indicators of seven strains from face-to-face cultivation in PDA media. The fermentation liquor of antagonistic strain was detected using thin layer, chromatography(TLC)and high performance liquid chromatography(HPLC). The experimental results showed that a total number of 121 strains of endophytes were isolated from Ziziphus jujube, including 49 strains of endophytic bacteria, 6 strains of endophytic actinomycetes, and 66 strains of endophytic fungi. Among of them, 54 strains(33 bacteria and 21 fungi)had obvious antagonistic activity against 1-7 indicative bacteria, accounting for 44.63% of the total, and six strains(A-04, A-05, B-03, C-03, C-06 and D-04)had a broad spectrum of antibacterial and antibacterial activity against seven strains of indicator microbes. Results from the analysis of TLC and HPLC showed that liquor in B-03 strain has the same color band with the migration rate of Ziziphus jujube extract in R_f value of 0.46, and its belonged to flavonoids. According to 16S rRNA gene sequences analysis. The similarity between strain B-03 and Bacillus axarquiensis was 99%. The strain of B-03 could produce flavonoids or similar compounds, which showed that the endophytes from Ziziphus jujube had the potential ability to produce new drugs of flavonoids.