Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya.
Microbiologyopen. 2017 Oct;6(5). doi: 10.1002/mbo3.497. Epub 2017 Jun 21.
Endophytic and plant-associated bacteria were isolated from plants and rhizoplane soil of naturally grown Brachiaria grasses at International Livestock Research Institute in Nairobi, Kenya. Eighty-four bacterial strains were isolated from leaf tissues, root tissues, and rhizoplane soil on nutrient agar and 869 media. All bacterial strains were identified to the lowest possible taxonomic unit using 16S rDNA primers and were characterized for the production of Indole-3-acetic acid, hydrogen cyanide, and ACC deaminase; phosphate solubilization; siderophore production; antifungal properties; and plant biomass production. The 16S rDNA-based identification grouped these 84 bacterial strains into 3 phyla, 5 classes, 8 orders, 12 families, 16 genera, and 50 unique taxa. The four most frequently isolated genera were Pseudomonas (23), Pantoea (17), Acinetobacter (9), and Enterobacter (8). The functional characterization of these strains revealed that 41 of 84 strains had a minimum of three plant beneficial properties. Inoculation of maize seedlings with Acinetobacter spp., Microbacterium spp., Pectobacterium spp., Pseudomonas spp., and Enterobacter spp. showed positive effects on seedling biomass production. The ability of Brachiaria grasses to host genetically diverse bacteria, many of them with multiple plant growth-promoting attributes, might have contributed to high biomass production and adaptation of Brachiaria grasses to drought and low fertility soils.
从肯尼亚内罗毕国际畜牧研究所自然生长的臂形草植物和根际土壤中分离出内生和植物相关细菌。从叶片组织、根组织和根际土壤在营养琼脂和 869 培养基上分离出 84 株细菌。使用 16S rDNA 引物将所有细菌菌株鉴定到最低可能的分类单元,并对其产生吲哚-3-乙酸、氰化氢和 ACC 脱氨酶、溶磷、产生铁载体、抗真菌特性和植物生物量生产进行了表征。基于 16S rDNA 的鉴定将这 84 株细菌分为 3 个门、5 个纲、8 个目、12 个科、16 个属和 50 个独特的分类单元。最常分离到的四个属是假单胞菌(23 株)、泛菌属(17 株)、不动杆菌属(9 株)和肠杆菌属(8 株)。这些菌株的功能特征表明,84 株中有 41 株至少具有三种植物有益特性。用不动杆菌属、微杆菌属、果胶杆菌属、假单胞菌属和肠杆菌属接种玉米幼苗显示出对幼苗生物量生产的积极影响。臂形草植物能够容纳遗传上多样化的细菌,其中许多具有多种促进植物生长的特性,这可能有助于臂形草植物的高生物量生产和适应干旱和低肥力土壤。