Study On The Screening,Identification And Optimization Of Fermentation Conditions Of High Producting Amylase Monascus And Its Properties Of Enzyme

Monascus produce amylase which decomposes starch to produce glucose in order to meet the industrial requirement.This paper collected different shapes Monascus-fermented rice throughout the country and grinded it into powder.386 strains Monascus were collected by culturing the powder on PDA medium and transferring single colonies more than three generations.Through primary screening and fermentation screening of 386 Monascus strains,Mp-42 strain of high producting amylase was obtained.The Mp-42 strain was identified as Monascus purpureus by morphology observation?detection indexes of physiological and biochemical as well as the result of ITS genetic sequence amplification and analysis.Under the condition of no optimization:beef paste 0.3%,peptone 1%,NaCl 0.5%,fermentation temperature 30?,fermentation pH 5.0,amylase activity of Mp-42 strain was up to 138.65 U/mL.Mp-42 strain activity of producing amylase was improved by mono-factor experiment and response surface methodology.Finally,optimum cultivation condition was starch 0.75%,peptone 3.81%,NaCl 0.49%,fermentation temperature 30?,fermentation pH 6.0.Under the optimal reaction conditions,enzyme activity was as high as 170.43 U/mL and was 1.23 times than original medium.At the same time,The optimum catalysis temperature and pH value were 70? and 5.0 respectively.By studying the influence of Mg2+?Cu2+?Ca2+?Mn2+?Na+?K+for Mp-42 strain producing amylase,the experimental results showed that the amylase activity was greatly stimulated by Na+ in six different kinds of metal ions.Puting seed liquid which cultivated 3 days into the 2 L fermentation liquid with 20%inoculation amount to detect biomass,enzyme activity and total protein of Mp-42 strain.The research results had shown that total protein achieved the largest of 0.45 mg/mL when strains grew 56 h,enzyme activity achieved the highest of 235.98 U/mL and biomass achieved the largest of 57.87 g/L when strains grew 60 h.According to salting-out of ammonium sulfate and freeze drying technology.46.78 g amylase solid agent had been acquired.Enzyme activity of the freeze-dried power was 173.62 U/g.