广西杨梅根瘤Frankia菌的分离和培养特性研究

Isolation and Cultural Features of Frankia on Root Nodule of Red Bayberry in Guangxi

采用根瘤切片法从广西本地杨梅根瘤中分离获得3株内生菌,经镜检、革兰氏染色和BAP无氮培养基培养,证实这3株内生菌为Frankia sp.,分别命名为MF3、MF6和MF9。对这3株分离株在不同碳源、氮源和pH值的培养特性进行研究。结果表明,3株分离株在分别以吐温-80、葡萄糖、丙酸钠为碳源的BAP培养基上生长良好,3株分离株对琥珀酸钠的利用较差;适宜的氮源为酵母膏、酪蛋白和氯化铵,尿素的利用率低。3株分离株均适合在pH 5.5～6.5范围内生长,pH 7.0以上生长受到抑制。

Three endophytes,isolated from root nodules of red bayberry（Myrica rubra） by nodule sectioning in Guangxi,were identified as Frankia sp.dubbed MF3,MF6 and MF9.based on the results from microscopic examination,Gram-staining,and cultural characteristics on N-deficient BAP medium.Effects of carbon sources,nitrogen sources and pH on three Frankia strains were studied by microscopic.The results showed that three Frankia strains grew very well on BAP medium with tween-80,glucose, sodium propionate as sole carbon source respectively,but the three strains didn＇t respond well to amber acid.Yeast extracts, casamino acid and ammonium chloride turned out to be appropriate nitrogen source.The utilization rate of urea was low.The three strains grew well under the range of pH5.5-6.5,but they were inhibited with the pH value over 7.0.