黑麦草根际铁载体产生菌 WN-H3的分离鉴定及其产铁载体培养条件的优化

摘要

从黑麦草（Lolium perenne L.）根际土壤中分离得到28份菌株，采用刃天青（chrome azural S，CAS）平板检测法定性、定量筛选出1株产铁载体能力较强的细菌 WN-H3，经过菌落形态、生理生化特征、16S rDNA 序列同源性和系统发育分析，初步判断为一株弗村假单胞菌（Pseudomonas vranovensis）。在摇瓶水平上采用单因子法分别研究了铁载体合成菌株 WN-H3的碳、氮源利用效果及培养温度、摇床转速、培养基初始 pH 值等因素对菌株生长及铁载体合成能力的影响，最终优化得到铁载体产生菌的最佳发酵条件：蔗糖10 g/L，酵母浸出粉5 g/L，NaCl 5 g/L，温度28℃，转速180 r/min，pH7.5，该条件下培养48 h 后菌株 WN-H3产生的铁载体活性 su 值可达80.4%。实验表明，优化后的培养条件更利于铁载体产生菌的生长和铁载体合成。%By mean of the chrome azural S(CAS)assay,a high-affinity siderophore- producing bacteria WN-H3 was screened out from 28 bacteria,which were isolated from the ryegrass(Lolium perenne L.)rhizosphere soil. According to morphological,biochemical and physiological characteristics,16S rDNA sequence and phylogenetic analysis,the strain was identified as Pseudomonas vranovensis. The optimal medium components(carbon and nitrogen sources)and growth conditions(temperature,rotation speed and initial pH)for siderphore production by strain WN-H3 were researched by one variable-at-a-time method. The result demonstrated that high siderophore production was yeilded at high siderophore- producing ability of 80.4% under the condition of 10 g/L sucrose,5 g/L yeast extracion,5 g/L NaCl,temperature 28℃,initial pH7.5,180 r/min.