摘要
不同土壤类型钾矿物分解细菌资源调查和高效稳定释钾、促生细菌的筛选鉴定有助于丰富微生物资源库,发掘和利用钾矿物分解细菌以及探究矿物生物风化机理等。作者采用以钾长石为唯一钾源的选择性细菌培养基,从山东地区不同土壤和不同植物根际土壤中分离纯化了23株生长势良好的钾矿物分解细菌,通过测定细菌代谢产物IAA和铁载体,研究其产生促生物质的能力,通过摇瓶试验筛选高效释钾菌株,采用16S rDNA限制性酶切多态性分析(amplified rDNA restriction analysis,ARDRA)方法研究了钾矿物分解细菌的遗传多样性,根据16S rDNA同源性对高效释钾菌株进行了鉴定。结果表明,供试菌株均产吲哚乙酸或其衍生物,43.5%的分离菌株产极高量铁载体。ARDRA结果表明供试菌株在60%相似性水平上可分为11个基因型,同一类型土壤上不同作物根际或不同类型土壤上同一作物根际的钾矿物分解细菌存在明显的遗传差异。摇瓶试验结果表明供试菌株中具有较显著释钾能力的菌株占17%,39%的供试菌株无释钾能力。筛选到2株高效释钾菌株AFM2、AC2,分别使溶液中钾含量增加了29.8%和25.4%。16S rDNA同源性分析表明菌株AC2、AHZ1与Bacillus mucilaginosus聚为一群,该群与包含菌株AZH4的Paenibacillus sp.中的种聚为一大发育分支,该分支在细菌分类地位上隶属于Firmicutes;菌株AFM2与Rhizobium sp.和Agrobacterium tumefaciens聚为另一大发育分支,该分支在细菌分类地位上隶属于Alphaproteobacteria。
In the search for mineral potassium-solubilizing bacterial strains with multiple activities that may be relevant for a beneficial plant-microbe interaction-potassium solubilization, indoleacetic acids （IAA） and siderophore production, a total of 23 heterotrophic eugenic strains were isolated from rhizospheric soil in Shandong Province using a medium with feldspar as the sole K source. All strains produced IAA or their derivatives, and 43.5% of the strains displayed a very high level of siderophores. Seventeen percent of the strains showed better growth on feldspar and effects on solubilization of K in liquid cultures, suggesting that they were a valuable pool for discovering plant growth-promoting bacteria. Two bacterial strains, AFM2 and AC2, exhibited greater K release efficiency than other isolates. Amplified rDNA restriction analysis （ARDRA） revealed that all isolates could be divided into 11 groups at the similarity level of 60%. Most strains exhibited a unique 16S rDNA restriction pattern even when strains were isolated from the same soil type or plant species. Strains AC2 and AHZ1 of group Ⅺ were highly related to Bacillus mucilaginosus, strain AFM2 of group Ⅳ shared 99% sequence homology with Agrobacterium tumefaciens.
出处
《生物多样性》
CAS
CSCD
北大核心
2008年第6期593-600,共8页
Biodiversity Science
基金
国家自然科学基金(30400006)
关键词
钾矿物分解细菌
IAA
铁载体
遗传多样性
mineral potassium-solubilizing bacteria, IAA, siderophores, genetic diversity
