Optimization Of Liquid Fermentation Conditions Of Bacillus Subtilis And Its Application In Corn Planting

Bacillus subtilis is widely found in nature,does not pollute the environment,and is harmless to humans and animals.At the same time,it has been widely used in agriculture,biological control and other aspects.As a model strain of Bacillus,it has become a commonly used strain in bio-organic fertilizer due to its own advantages.However,in the actual production process,it is often affected by the strain source,fermentation conditions,etc.,so that the final product can not achieve the desired application effect.This paper mainly selects one strain of Bacillus subtilis from GT007-KC001,GT012-KC005,GT014-KC007 and GT016-KC009 provided by the National Microbial Fertilizer Technology Research and Promotion Center,and is selected by the National Microbial Fertilizer Technology Research and Promotion Center.Based on the formulation of the fermentation medium provided,the liquid fermentation conditions are optimized,and then the expansion culture is carried out.Finally,the product is produced into a bio-organic fertilizer applied to corn,and it is hoped that the actual production and application of Bacillus subtilis can be provided.Theoretical basis.The main findings of this paper are as follows:1.For GT007-KC001,GT012-KC005,GT014-KC007 and GT016-KC009,four strains of Bacillus subtilis were tested for effective viable counts of the base fermentation broth,and the strains were resistant to acid at pH values of 1.5,2.5,3.5 and 4.5.The ability was compared.Finally,Bacillus subtilis GT014-KC007 was selected as the dominant strain for comparison at high temperature resistance of 50°C,60°C,70°C and 80°C.2.The liquid fermentation conditions of Bacillus subtilis GT014-KC007 were optimized by single factor test.The initial pH value was 7.0,the inoculum volume was 10%,the liquid volume was 150 mL,the culture temperature was 32°C,and the shaking speed was180 r·min^-1,culture time 48 h as the optimum shaker culture condition.Finally,the effective viable count reached 6.3×10⁹CFU·mL^-1.3.Bacillus subtilis GT014-KC007 was subjected to liquid fermentation in 5 L fermentor and 10000 L fermenter.The effective viable counts were 6.1×10⁹CFU·mL^-1and7.0×10⁹CFU·mL^-1,indicating that the optimized liquid fermentation conditions were It is feasible in the actual production process.4.On the basis of compound fertilizer,1 bag of bio-organic fertilizer was added per acre to study its application effect on corn planting.In the growth index of maize,the number of theoretical emergence increased by 356 plants/mu,the rate of seed formation was 1,the number of grains per ear increased by 28.27 grains/ear,the weight of 1000 grains decreased by 3.29 g,and the yield per mu increased by 83.05 kg.The content of starch and protein in corn quality factor did not increase significantly,and the fat content increased by 0.41 g/100 g,10.05%.In terms of economic benefits,the mu income increased by 141.19 yuan,and the net increase was 91.19 yuan.