产铁载体菌株的分离、培养条件优化及初步应用  

Isolation,culture condition optimization,and preliminary application of siderophore-producing strains

作　　者：许佳露 张平 李美芳[1,2] 廖柏寒 彭佩钦[1,2] 李靖 梅金星[1,2] XU Jialu;ZHANG Ping;LI Meifang;LIAO Bohan;PENG Peiqin;LI Jing;MEI Jinxing(College of Environmental Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,Hunan,China;Hunan Engineering Laboratory for Control of Rice Quality and Safety,Central South University of Forestry and Technology,Changsha 410004,Hunan,China)

机构地区：[1]中南林业科技大学环境科学与工程学院,湖南长沙410004 [2]中南林业科技大学稻米品质安全控制湖南省工程实验室,湖南长沙410004

出　　处：《微生物学通报》2022年第3期1004-1016,共13页Microbiology China

基　　金：国家重点研发计划(2017YFD0801105);农业部与财政部科研专项(农办财函[2016]6号);湖南省重点学科建设项目(2006180)。

摘　　要：【背景】微生物菌肥是推动绿色农业发展的关键。铁载体是由植物根际微生物产生的一类低分子量金属离子螯合物,可通过螯合Fe^(3+)促进植物生长,因此,筛选具有高产铁载体功能的菌种意义重大。【目的】从植株根际土壤中分离高产铁载体微生物,为开发植物根际促生菌提供种质资源。【方法】采用chrome azurol sulfonate(CAS)平板覆盖法分离、纯化获得高产铁载体真菌菌株,通过形态观察及18S rRNA基因序列分析对菌株进行鉴定,在此基础上,采用单因素实验法优化其产铁载体条件,并通过上海青水培试验,初步考察菌株的促生效应。【结果】分离获得4株产铁载体真菌菌株,其中一株菌产铁载体能力相对较强,编号为RL1,初步鉴定为黑曲霉(Aspergillus niger)。RL1的最佳产铁载体培养条件为:初始pH 5.0,碳源葡萄糖含量5 g/L,温度20℃,培养时间5 d,转速60 r/min。随着RL1菌悬液浓度的增加,上海青植株的鲜重和叶片光合色素含量均逐渐增大。当施加最大浓度孢子菌悬液(3.2×10^(8)CFU/m L)时,植株的总鲜重量和茎叶鲜重量增幅分别为75.0%和74.4%,叶绿素a、叶绿素b和类胡萝卜素含量增幅分别为49.8%、70.9%和26.7%。【结论】本研究分离获得一株高产铁载体真菌菌株RL1,优化后的培养条件更利于菌株铁载体的合成,而且该菌株能够有效促进上海青幼苗的生长。[Background]The key to promoting green agriculture is microbial fertilizer.Siderophore is a low molecular iron chelate produced by rhizosphere microorganisms,which can promote plant growth by chelating Fe^(3+).Therefore,it is of great significance to screen out the strains with high-yield siderophore.[Objective]In order to provide germplasm resources for the development of plant growth-promoting bacteria,we isolated high-yielding siderophore microorganisms from rhizosphere soil.[Methods]A fungal strain with high yield of siderophore was isolated and purified by chrome azurol sulfonate(CAS)overlay plate method.The strain was identified based on morphological observation and 18 S rRNA gene analysis.The culture conditions for siderophore production were optimized by single factor experiment,and the growth-promoting effect of the strain was preliminarily investigated by hydroponic experiment of Chinese cabbage.[Results]Four strains of siderophore-producing fungi were isolated,one of which with strong siderophores-producing ability was numbered RL1 and preliminarily identified as Aspergillus niger.The optimal culture conditions for siderophore production of strain RL1 were as follows:initial pH 5.0,carbon source of glucose at 5 g/L,temperature at 20℃,culture time of 5 days,and rotational speed of 60 r/min.The fresh weight and photosynthetic pigment content of Chinese cabbage increased with the increase in the concentration of RL1 suspension.When the maximum concentration(3.2×10^(8)CFU/mL)of suspension was applied,the total fresh weight and the aboveground weight of Chinese cabbage increased by 75.0%and 74.4%,respectively,and the content of chlorophyll a,chlorophyll b,and carotenoid increased by 49.8%,70.9%and 26.7%,respectively.[Conclusion]In this study,a fungal strain RL1 with high-yield siderophore was isolated.High siderophore production of the strain was achieved at optimized culture conditions,and the strain could effectively promote the growth of Chinese cabbage seedlings.

关 键 词：微生物 铁载体 条件优化 水培试验 鲜重 光合色素 

分 类 号：S144[农业科学—肥料学]