Study On Fermentation Kinetics Of Bacillus Amyloliquefaciens Q-426 Fermentation To Produce Antibacterial Substances

Bacillus amyloliquefaciens Q-426 was isolated with a broad spectrum of antibacterial activity of strain obtained from a strain of compost,can be widely inhibit fungal and bacterial activity,students long fast,good stability,some prospects for the development of biological pesticide.The study on Bacillus amyloliquefaciens Q-426 fermentation production of antimicrobial peptides,in shake flask level on industrial training of medium optimization,as well as in Switzerland tank KLF-2000 3.7L fermentor was studied on the optimization and fermentation kinetics of fermentation process.The results are as follows:Then through the plackeet-Burman(P-B)experiment,the steepest ascent experiment,Box-Behnken(BB)experiment,response surface analysis,the best culture medium formula was:response surface method is employed to optimize culture medium.The optimized medium is(g/L):glucose 3.92,ammonium chloride 0.19,magnesium chloride 3.83,beef extract 5.00.Through the optimization of Bacillus amyloliquefaciens Q-426 produced antimicrobial lipopeptide antibacterial circle diameter was 29mm,than before optimization(25mm)inhibition zone size increased by 16%.Secondly,as a profound understanding of the nature of the microbial metabolism of complex,to find the most suitable operating conditions,this paper constructed a BP neural network and predict its metabolic activity,results showed that the calculation and prediction of antimicrobial peptides on Bacillus amyloliquefaciens Q-426 fermentation was feasible,and provides a theoretical basis for the optimization control the fermentation process.Third,study the influence of pH,temperature,speed of antibacterial lipopeptide,in Switzerland tank KLF-2000 3.7L fermentor.Through the analysis of kinetic parameters,using piecewise control of pH,temperature,speed,4h before fermentation control speed was 300r/min,4～40h speed control for 500r/min.Controlling the temperature of fermentation:in the former 8h fermentation temperature control in 30℃,8～30h under the temperature of 38℃,30～40h temperature control in 36℃.The fermentation process of pH control:0～14h,the pH control in 6.5,12h～40h,pH control in 7.0.to the end of the fermentation,compared with a single control strategy,antibacterial activity and biomass was improved.Finally,based on the medium and fermentation condition optimization of post industrial culture,for batch fermentation experiment.The change of cell dry weight,size,theantibacterial activity of substrate concentration,of Bacillus amyloliquefaciens Q-426 batch study on fermentation kinetics model,nonlinear fitting by MATLAB201 lb,establishment of cell growth,synthesis of antibacterial lipopeptide and total sugar consumption 3 fermentation kinetics model.The results show that the model can better reflect the Bacillus amyloliquefaciens Q-426 fed batch fermentation process of antimicrobial peptide.