Establishment Of Kinetics Digital Model For Avilamycins Production And Metabolomic Analysis Based On The Addition Of Precusor Substance

Avilamycin is a kind of orthosomycin antibiotics,which was widely used as a new type of metabolic regulator and digestive enhancer in livestock feed.This paper optimized the fermentation condition in 30 L fermentor and investigated the fermentation dynamics.Meanwhile,this paper screed some precusor substance which can raise avilamycin production effectively,and analyzed the difference of metabolism by metabonomics.First,This paper optimized the fermentation condition in 30 L fermentor,The S.viridoehrongenes gs 77-54 was used as original strain,we optimized the batch fermentation conditions in a 30 L fermentation tank by single-factor methodology.These study results indicated that the bacterial biomass and avilamycin production respectively reached the highest 23 g/L、1571.04 mg/L at 228 h when the fermentation initial pH was 7.5,the voluntary ventilation was 2.0 vvm,and 0.1%L-Val was added every 24 hours.Then,we studied the fermentation kinetics based on the streamlined fermentation condition,the relation between the cell growth,avilamycins production and glucose with the fermentation time was reached by timed sampling test.Then we developed a mathematical model based on the Logistic equation for cell growth,the mass balance equation for total sugar consumption and the Luedeking-Piret equation for avilamycins production to describe the dynamic kinetics of the avilamycins production.Then nonlinear fitting were obtained by ORIGIN.The fit degrees of the three individual models are 0.986,0.987 and 0.991 respectively,which indicated that the model can reflect the avilamycins batch fermentation kinetic processes well.Meanwhile,this study compared the influences of some Small molecular precusor substance on production of avilamycin with S.viridoehrongenes gs 77-54 fermentation by Shake flask test.These results indicated that,the sodium succinate,Sodium acetate,sodium citrate,y-aminobutyric acid,D-ribose can improve the avilamycin production.The 0.6%sodium citrate can best make the avilamycin production increased 23.44%.Then examined the inference of these precusor substance on avilamycin fermentation with S.viridoehrongenes gs 77-54 by Plackett-Burman experiment,and got three major factors,the sodium citrate,sodium acetate and sodium succinate.Finally,we obtained the optimal adding strategy of precusor substance on avilamycin fermentation through the steepest uphill experiment and Box-Behnken:Concentration of sodium succinate 0.05%(g/v),sodium citrate 0.4%,and sodium acetate 0.22%.Under this adding conditions,the relative content of avilamycin can reach to 138.40%,no significant difference compare with theory predicts.The avilamycin production can reach to 2174.32μg/mL when the shake-flask fermentation finished.Next,This paper lucubrated the difference of metabolism after these small molecular precusor substance addition with metabonomics methods.We contrasted the fermentation process with the precusor substance and without them.By timed sampling studies,GC-MS detection and data analysis with SIMCA-P software,we successfully matched 53 kinds of intracellular metabolites,and combined the Partial least-squares regression and Variable importance of the projection plots(VIP),we obtained 18 kinds the most relevanted intracellular metabolite.Then,we conjectured a possibly S.viridoehrongenes gs 77-54 metabolic process path by the changes of intracellular metabolites,and after compared the change tendencies of the intracellular metabolites,we speculated the addition of sodium citrate,sodium acetate and sodium succinate can inhibit the Tricarboxylic acid cycle of S.viridoehrongenes gs 77-54 and enhance the glucide metabolic pathways to increase the avilamycin production.