一株高效解磷菌Bacillus subtilis JT-1的筛选及其对土壤微生态和小麦生长的影响

Screening of a high-efficiency phosphate solubilizing bacterium Bacillus subtilis JT-1 and its effects on soil microecology and wheat growth

为开发高效解磷微生物菌肥,提高磷肥利用效率,从磷矿土壤中筛选出1株高效解磷菌,经16S r DNA鉴定为枯草芽孢杆菌,命名为Bacillus subtilis JT-1,通过钼锑抗比色法对其解磷能力进行定量分析,并通过GC-MS定性分析其代谢产物中的有机酸成分。将该解磷菌制备成菌剂施用于土壤和盆栽小麦,对土壤中有效磷含量、可培养微生物数量和微生物群落多样性进行了分析,同时测定了小麦的基本生长指标及对磷肥的利用效率。结果表明,B.subtilis JT-1在难溶磷培养基中的解磷率高达38.69%,具有分泌苹果酸、延胡索酸、琥珀酸、柠檬酸等溶磷有机酸的特性。施入土壤后可有效提高土壤中可溶磷含量和可培养微生物的数量,明显提高土壤微生物群落结构的多样性。此外,菌株JT-1还提高了磷肥的利用率10.79个百分点,促进小麦增产12.31%。因此,筛选到的解磷菌B.subtilis JT-1具有较高的理论研究意义和应用价值。

In order to develop high-efficiency phosphate solubilizing microbial fertilizer and improve the utilization efficiency of soil phosphate fertilizer, a bacterium was isolated from mineral phosphate soil. By 16S rDNA sequencing, the strain was identified as Bacillus subtilis and named B. subtilis JT-1. The phosphate solubilizing capacity of JT-1 was quanti-fied by Mo-Sb colorimetry, and organic acids in the metabolites were identified by GC-MS. B. subtilis JT-1 prepared as mi-crobial fertilizer was applied to pot-cultured wheat the available phosphorus, microorganism count, and diversity of microbial species in the soil were analysed, and the growth indicators and phosphate utilization efficiency were measured. The results showed that the phosphate-dissolving rate of B. subtilis JT-1 was as high as 38-69% on insoluble phosphate me-dium, and it secreted malic acid, fumaric acid, succinic acid and citric acid. The content of available phosphorus, the microbial population, as well as the diversity of microbial species in soil were improved by B. subtilis JT-1. In addition, the utilization of phosphate fertilizer was increased by 10-79 per-cent points and wheat yield was enhanced by 12-31%. The re-search implies that B. subtilis JT-1 is of high theoretic significance and practical values.