一株赣南脐橙根际吲哚乙酸产生菌的筛选及其发酵特征

Screening and fermentation characteristics of one IAA-producing strain in rhizosphere of Gannan navel orange

为了给脐橙微生物肥料的研制和生产提供优良菌株,从赣南脐橙根际土壤中分离获得19株菌能产吲哚乙酸(Indole-3-Acetic Acid, IAA)的菌株,其中IAA-6菌株产IAA能力最强.对IAA-6菌株进行菌落形态观察和16S rDNA序列分析,利用分光光度法测定产IAA的能力,并对最佳碳氮源、产素等发酵条件进行了筛选.结果表明,IAA-6菌株菌落形态光滑、透明、黄色,初步命名IAA-6菌株为Pantoea sp. IAA-6,其最适发酵条件为p H为7,装液量为75 mL/250 mL,培养时间为29 h,碳源为淀粉,氮源为蛋白胨,IAA产量可达到33.299 mg/L.研究发现IAA-6菌株具有较强的IAA产生能力,具有作为脐橙功能微生物肥料研发的潜力,可进一步对其进行开发研究.

In order to provide excellent strains for development and production of microbial fertilizer utilization in Gannan navel orange,a total of 19 Indole-3-Acetic Acid(IAA)producing bacteria were successfully isolated from the rhizosphere soil of Gannan navel orange.Among them,the IAA-6 strain had the highest IAA prod uctivity.The colony morphology and 16S rDNA sequence was analyzed,the IAA productive ability was determined by using spectrophotometric method,and the fermentation optimization for IAA-6 strain wasd further carried out.The results show that the morphology of IAA-6 strain was smooth,transparent and yellow,and the IAA-6 strain was identified and named as Pantoea sp.IAA-6.The optimal fermentation conditions for IAA-6 strain were as follows:pH 7.0,a 75 mL medium in 250 mL Erlenmeyer flask,29 h of incubation time,starch as the carbon source,and peptone as the nitrogen source,in which the IAA yield could reach 33.299 mg/L.Due to the efficient IAA production capacity,it could be concluded that the IAA-6 strain has the potential to be used as a functional microbial fertilizer for navel orange,and is value for further development and research.