一株胶冻样芽孢杆菌培养条件的优化及其解钾活性

Optimization of the Culture Condition of a Jelly-like Bacillus Strain and Its Potassium-releasing Activity

[目的]优化该胶冻样芽孢杆菌培养条件及测定其解钾活性。[方法]用火焰光度计法测定胶冻样芽孢杆菌的解钾量;通过大白菜的田间试验验证解钾功能;通过培养基成分及培养条件的优化,获得最佳培养基和培养条件。[结果]用火焰光度计法测定胶冻样芽孢杆菌的解钾量为121.3 mg/L,其解钾率为12.06%;将其应用到喜钾作物大白菜上,通过大白菜的田间试验,与K_(0)(空白对照)组相比大白菜产量增加了15.5%,与只加硫酸钾的K_(1)相比,产量差异不大;通过培养基成分及培养条件的优化,获得最佳培养基配比为蔗糖1.0%、酵母浸粉0.1%、硫酸镁0.02%、磷酸氢二钾0.05%,最适培养条件为温度30℃、pH 7.0、转速200 r/min,发酵结果有效活菌数达到17.5×10^(8)CFU/mL,芽孢率≥95%,解钾率提高到23.02%。[结论]该胶冻样芽孢杆菌可以将土壤中不可直接被作物吸收利用的钾素分解为作物可以直接利用的速效钾形态。

[Objective]To optimize the culture conditions of the jelly-like Bacillus strain and determine its potassium-releasing activity.[Method]The potassium solubilization amount of Bacillus jelly was determined by flame photometer;the potassium solubilization function was verified by the field test of Chinese cabbage;the best medium and culture conditions were obtained through the optimization of medium composition and culture conditions.[Result]The amount of potassium release of Bacillus jelly measured by flame photometer was 121.3 mg/L,and the potassium release rate was 12.06%.It was applied to the potassium-loving crop Chinese cabbage,through the field test of Chinese cabbage,compared with the K0(blank control)group,the yield of Chinese cabbage increased by 15.5%;compared with K1 with only potassium sulfate,there was little difference in yield.Through the optimization of the medium composition and culture conditions,the best medium ratio was obtained sucrose 1%,yeast extract 0.1%,magnesium sulfate 0.02%,dipotassium hydrogen phosphate 0.05%,the most suitable culture conditions were temperature 30℃,pH 7.0,rotation speed 200 r/min,the effective number of viable bacteria reaches 17.5×10^(8) CFU/mL as a result of fermentation,the spore rate was≥95%,and the potassium solution rate was increased to 23.02%.[Conclusion]The Bacillus jelly can decompose the potassium in soil that cannot be directly absorbed by crops into quick-acting potassium forms that can be directly used by crops.