具有解钾活性假单胞菌的分离与鉴定

目的]分离并鉴定具有解钾活性假单胞菌。方法]以农田土壤为样本,在钾长石粉为唯一钾源的选择性培养基上分离并纯化解钾菌,并通过形态观察和16S r DNA序列分析对分离到的细菌进行鉴定。结果]经梯度稀释涂布和平板划线分离,经初筛获得8株生长良好并具有解钾透明圈的细菌。将初筛后获得的细菌菌株进行发酵培养,利用原子吸收分光光度法测定发酵上清液中的速效钾含量,从中筛选出解钾能力较强的1株假单胞菌K3。通过形态观察发现,该菌株为革兰氏阴性杆菌。16S r DNA序列分析结果表明,该菌株与荧光假单胞菌F113亲缘关系最近,初步确定该菌株属假单胞菌属。结论]该研究为微生物钾肥的开发提供了新的试材。

Isolation and Identification of a Potassium-releasing Strain of Pseudomonas sp.

Objective] To isolate and identify a potassium-releasing strain of Pseudomonas sp..Method] With farmland soil as the sample, po-tassium-releasing bacteria was isolated and purified on the selective medium in which potash feldspar powder was used as the only source of potas-sium.Morphologic observation and 16S rDNA gene sequence analysis were used to identify the isolated strains.Result] By using the methods of gradient dilution coating and streaking inoculation, eight presumed potassium-releasing bacteria strains exhibiting clear zones were selected and inoculated into fermentation medium.The potassium contents in supernatant were determined with flame atomic absorption spectrophotometry method.Among them, a strain named K3 was verified to be with relatively high potassium-releasing ability cause the potassium contents in the su-pernatant of fermentation culture greatly increased comparing to the control sample.Through morphological observation it was verified to be Gram-negative rod bacteria.The 16S rDNA gene sequence analysis result showed that it had most close genetic relationship with Pseudomonas fluorescens F113, thus tentatively identified as Pseudomonas sp..Conclusion] This research provides new test materials for the development of microbial potash fertilizer.