高效钾细菌的筛选鉴定及对植物的促生长效应

Screening and Identification of High-efficiency Potassium-solubilizing Bacteria and Their Growth-promoting Effects on Plants

为了筛选出解钾活性较强的细菌,缓解土壤缺钾状况,从森林土壤中分离筛选到5株解钾活性较强的钾细菌SK1-7、SK2-3、SK2-7、SK3-3、SK3-10。经形态学、生理生化比较及16S rRNA序列分析,将SK1-7鉴定为阿氏芽孢杆菌(Bacillus aryabhattai),SK2-3为黏着剑菌(Ensifer adhaerens),SK2-7为新加坡克雷伯氏菌(Klebsiella singaporensis),SK3-3为黄杆菌(Microbacterium maritypicum),SK3-10为解鸟氨酸拉乌尔菌(Raoultella ornithinolytica)。5株钾细菌在解钾培养基中培养7 d后,发酵滤液中钾离子含量分别为42.70、50.40、49.70、41.50、45.23μg/mL,且pH值也大幅度降低。5株钾细菌对番茄的促生长试验表明,SK1-7、SK2-3、SK2-7发酵滤液能促进番茄种子发芽率的显著或极显著提高。SK1-7、SK2-3、SK2-7菌株处理番茄植株40 d后,番茄的株高、鲜质量和干质量均有所增加。生物活性差异检测显示,5株钾细菌均能分泌生长素;SK2-7和SK3-10发酵液具有抑菌作用;SK1-7具有分泌蛋白酶能力。

In order to screen bacteria with strong potassium-dissolving activity,and to alleviate soil potassium deficiency,five strains of potassium bacteria(SK1-7,SK2-3,SK2-7,SK3-3,SK3-10)with strong potassium-dissolving activity were isolated and screened from forest soil.SK1-7,SK2-3,SK2-7,SK3-3,SK3-10 were identified as Bacillus aryabhattai,Ensifer adhaerens,Klebsiella singaporensis,Microbacterium maritypicum and Raoultella ornithinolytica respectively by morphological,physiological and biochemical experiments and 16S rRNA gene sequence analysis.Potassium ion contents in fermentation filtrate of the 5 strains of potassium-solubilizing bacteria were 42.70,50.40,49.70,41.50,45.23μg/mL,respectively after 7 days of incubation in the medium,and the pH values of fermentation filtrate were also significantly reduced.The growth-promoting test of 5 strains of potassium-solubilizing bacteria on tomato showed that,the fermentation filtrate of SK1-7,SK2-3,SK2-7 could improve the germination rate of tomato seeds significantly or extreme significantyl.Tomato plant height,fresh weight and dry weight increased after treatment of tomato plants with SK1-7,SK2-3,SK2-7 for 40 d.Biological activity difference tests showed that 5 strains of potassium-solubilizing bacteria could secrete IAA;the fermentation filtrate of SK2-7 and SK3-10 had antibacterial effects;SK1-7 exhibited stronger ability of secreting protease.