Liquid-fermented Peanut Meal Of Paenibacillus Polymyxa And Its Study Of Fermentation Characteristics

Peanut meal is rich in protein and amino acids,its'crude protein which is difficult to be directly absorbed by plants restricts its direct use as plant fertilizer.The rhizosphere plant growth promoting bacteria can decompose peanut meal efficiently,so as to promote the absorption of nutrition by plants.In this study,a strain of Paenibacillus polymyxa that can efficiently decompose peanut meal was selected.We also tested the protease activity of the selected strains,the growth characteristic determination and the high density culture,study on fermentation technology of liquid degradation peanut meal and the pilot study of liquid degradation of peanut meal.The study results are as follows:(1)8 strains were tested in protease hydrolysis circle,the ratio of transparent circle diameter to colony diameter of Paenibacillus polymyxa is the largest,which is3.530.The protease activity of the strain was determined to be 6.76U/mL.The results shows that the strain has the ability of producing protease and decomposing protein.(2)The growth characteristics and high density culture of Paenibacillus polymyxa which we screened were studied.The best culture conditions are as follows:pH is 6.0,temperature is 35?,culture time is 48h,liquid content is 100mL/250ml,inoculation amount is 3%,shaking table speed is 150r/min.(3)The liquid fermentation process of this strain to degrade peanut meal was studied.The optimal fermentation process is as follows:the fermentation time is 5days,the fermentation temperature is 34?,the ratio of material to liquid is 1:15,the inoculation amount is 2%,the ratio of peanut meal to glucose is 8:2.Under these conditions,the degree of hydrolysis is 94.4%.(4)In the pilot test of degrading peanut meal,the pH value,viable bacteria,dissolved oxygen,crude protein,amino acid and small peptide before and after fermentation were determined.The results are as follows:the pH value decreased from 5.81 to 5.28,which decreased by 0.53;the number of viable bacteria increased from 0 to 2.62×10~8CFU/g,dissolved oxygen decreased from 8.2mg/L to 0;crude protein increased from 51.84%to 59.70%,increased by 7.86%;total amino acid increased from 14.42%to 16.71%,increased by 2.19%;small peptide increased from2.38%to 9.01%,increased by 6.63%.It can be seen that the Paenibacillus polymyxa has been well propagated and decomposed peanut meal in the determined fermentation tank environment.The experiment includes the screening of hydrolysis circle,the determination of growth characteristics and high-density culture,the study of liquid fermentation technology of peanut meal by strains,and the pilot test of degrading peanut meal.We screened a strain that can decompose peanut meal efficiently,and optimized the best culture conditions and fermentation conditions of the strain.It provides a basis for the high-density culture of the strain in the future,and also provides resources for liquid organic fertilizer.