Optimization Of Paenibacllus Azotofixans Fermentation Technology And Its Application In Red Kidney Bean

Paenibacllus azotofixans is a kind of strain which can fix nitrogen and produce spores.It has a control effect on Sclerotinia sclerotiorum,Gibberella zeae,Verticillium dahliae and other pathogenic bacteria.In recent years,with the rapid development of agriculture,the scale of microbial fertilizer production has been expanding,and the production of Bacillus spp has also begun to be used in practical production,and the production of spores is the key factor affecting the practical application of the product.In this paper,the liquid fermentation technology of Paenibacllus azotofixans was optimized and the 1m~3 fermentor was used to produce granular liquid fermentation.Biological organic fertilizer.Secondly,British red kidney bean was used as experimental material to study the application of fermentative products through one-year and two-experiment application of bio-organic fertilizer,which provided a theoretical basis for the research and development and promotion of Paenibacllus azotofixans.The main research results of this paper are as follows:1)In this study,three kinds of medium were collected for the fermentation of Paenibacllus azotofixans.Through shaking flask test,the most suitable fermentation medium formulation(peptone 10g,yeast extract 5g,sodium chloride2.5g,glucose 10g,distilled water 1000mL)was selected as the initial fermentation medium formulation for the following experiments.The optimum carbon source and the amount of carbon source added to the initial fermentation medium were optimized,and the corresponding results were glucose and 15g/L.Compared with the initial fermentation medium,the bacterial content of fermentation broth increased by1.58×10~8/mL.2)The effect of fermentation conditions on the content of bacteria in fermentation broth was obtained by orthogonal test.The importance of fermentation conditions was A(liquid loading)>B(culture temperature)>C(rotation speed).The optimum fermentation conditions of Paenibacllus azotofixans were as follows:100mL of liquid,30 C of culture temperature and 200 r/min of rotational speed.Under this fermentation condition,the content of bacteria in the fermentation broth was5.83±2.28×10~8/mL,which was 3.7×10~8/mL higher than that in the initial fermentation condition,which was 2.13×10~8/mL.3)After optimizing the fermentation medium and fermentation conditions in shaking flask,1m~3 liquid fermentation tank was used for fermentation culture.The morphology,quantity and pH value of Paenibacllus azotofixans during liquid fermentation were observed,and dissolved oxygen was dynamically adjusted.The final bacterial content of fermentation broth was 11.3×10~8/mL.The feasibility of the optimized fermentation system was verified.4)The pod length,protein,yield per hm~2 and net profit of the experimental group increased by 5.62%,23.92%,7.46% and 4.37% respectively compared with the conventional fertilizer group,while the pod length,grain density,protein,yield per hm~2 and net profit of the experimental group increased by 3.76%,4.13%,31.43%,6.37% compared with the conventional fertilizer group.53% and 3.93%.Overall,the application of bio-organic fertilizer can effectively improve the quality of red kidney bean and increase the yield of red kidney bean.