Fermentation Of Peanut Meal By Bacillus Amyloliquefaciens And Its Molecular Mechanis

Peanut meal is the raw material of peanut kernels after peeling,and the remaining product after refining oil.It is mainly used as animal feed or plant fertilizer,but very few are intensively processed,resulting in low added value of products and a lot of waste of resources.In this study,the method of treating peanut meal with alkaline protease followed by Bacillus amyloliquefaciens was used to improve the utilization rate of peanut protein.The Illumina Hi Seq sequencing system was used to perform whole-genome sequencing of Bacillus amyloliquefaciens,and various information software were used to perform COG annotation and metabolic system analysis of the Bacillus amyloliquefaciens genome.The main results of the study are as follows:（1）Preliminarily screened 13 kinds of enzymes purchased in the market,and set the optimum conditions of each enzyme respectively.Taking the degree of hydrolysis as an indicator,the degree of hydrolysis of peanut meal treated with alkaline protease was the highest,which was 45.6%.（2）Through single factor test and orthogonal test,the conditions of various factors for enzymatic hydrolysis of peanut meal were optimized,and the best experimental plan was obtained:substrate concentration 50g/L,p H value 8.5,enzymolysis time 24h,enzyme dosage0.20%,the enzymatic hydrolysis temperature is 35℃.Under these conditions,the degree of hydrolysis of peanut meal was 36.4%.（3）Preliminary screening of 8 strains preserved in the laboratory,through the hydrolysis circle test and the colony count test,with the diameter ratio of the transparent circle to the colony and the colony number as indicators,it was found that Bacillus amyloliquefaciens has a strong ability to decompose peanut meal,The number of colonies was the largest.The ratio of the diameter of the transparent circle to the colony was 3.46,and the number of colonies was9.55×10¹⁰CFU/ml.（4）The various factors and conditions of the fermentation test were optimized by single factor test and orthogonal test.Under the conditions of p H 7.5,fermentation temperature of30°C,and rotation speed of 150 r/min,the optimal fermentation conditions were obtained:the amount of bacteria added was 0.15%.,the fermentation time was 48h,the addition of industrial glucose was 0.15%,and the degree of hydrolysis after fermentation was 53.8%.（5）Using Diamond software to compare to the Egg NOG database,3035 protein genes of Bacillus amyloliquefaciens were divided into 20 COG subclasses.Except for the number of genes with unknown functions,the amino acid transport and metabolism of Bacillus amyloliquefaciens were the largest.,transcription and carbohydrate transport and metabolism are also very active,which may be related to the translation and synthesis of proteins.（6）Compared with the CAZy database using Diamond and hmmscan analysis software,there are 127 CAZyme-encoding genes expressed in the Bacillus amyloliquefaciens genome.Using anti SMASH software analysis,it was found that the Bacillus amyloliquefaciens genome has 16 secondary metabolite synthesis-related gene clusters,which are similar to various gene clusters with functions such as inhibiting bacteria and fungi,indicating that Bacillus amyloliquefaciens also has similar functional properties.