Study On The Aminopeptidase From Monascus

Monascus can produce a variety of biologically active enzymes:amylase, glucoamylase, maltase, protease, pectinase, lipase, ester enzyme, carboxypeptidase, aminopeptidase enzymes and so on. Aminopeptidase is a protease, which play a important role in debittering protein hydrolyzate and the depth hydrolysis of proteins. Relative to extract aminopeptidase form animals and plants, microbial fermentation of aminopeptidase has the advantages of low-cost, large output, high activity.This paper focuses on solid state fermentation and liquids state fermentation of aminopeptidase by Monascus, screening out the optimal conditions for production of aminopeptidase. aminopeptidase were purified bying using two aqueous phase extraction and ultrafiltration and we explorated the process which could enlarge the extraction of aminopeptidase. In addition, we preliminary studied the enzymatic properties of purified aminopeptidase.Solid-state fermentation and liquid fermentation condition of aminopeptidase by Monascus were optimized, enzyme production conditions optimization, the results showed that: liquid fermentation of aminopeptidase costed relatively shorter time. And enzyme activity reached the maximum activity after7days, which was376.9U/mL.on the other hand, enzyme by Solid state fermentation after13days which was115.3U/mL.How to purify crude aminopeptidase solution in Monascus fermentation products was studied and the results showed that after making Linear amplification experiment Of optimized two aqueous phase extraction system based on crude solution producing by solid fermentation, protein partition coefficient KP, enzyme purification coefficient K and the recovery rate of enzyme were almost does not change, indicating that this system can be expand used for aminopeptidase crude enzyme extraction.In accordance with the conditions of the aqueous two-phase system:pH7.5, the mass fraction of18%(NH4)2SO4, the mass fraction of18%PEG-2000, zoom in aqueous two-phase system,500times, respectively extracting the crude enzyme A and liquid fermentation products from the crude enzyme B in the1000mL solid fermentation product extraction by ultrafiltration with the optimum pressure0.1Mpa,30kDa polyethersulfone hollow fiber membranes were concentrated two times to the initial purification, the results showed that: the specific activity of the purified aminopeptidase enzyme A from the crude enzyme A reached153,589.46(U), the purification factor of6.3, the specific activity of the purified aminopeptidase enzyme B from the crude enzyme B reached261,481.61(U),the purification factor of9.34.The preliminary study results with the enzymatic properties on the aminopeptidase enzyme A purified in solid state fermentation of Monascus and the aminopeptidase enzyme B purified in the Monascus liquid fermentation showed that: A half-life of the aminopeptidase enzyme general downward trend is about20days, the aminopeptidase enzyme solution B half-life is about24days,so the activity of two aminopeptidase is similar; The most suitable temperature for the enzyme solution is40℃, the optimum pH range is7.5to9alkaline; low concentrations of metal ions two aminopeptidase enzyme activity has little effect, high concentrations of Zn2+has a higher inhibitory effect of high concentrations of Co2+activation.