Optimization of Paenibacillus polymyxa 20185 fermentation conditions for producing alkaline pectinase

The medium components and fermentation conditions for the alkaline pectinase produced by Paenibacillus polymyxa 20185 fermentation were studied.The optimized fermentation medium determined by single factors and orthogonal analysis methods was(g/L): pectin 10.0,tryptone 20.0,K2HPO4·3H2O 6.0,KH2PO4 3.0,NaCl 10.0,MgSO4·7H2O 0.2,SDS 1.0.The corresponding optimum fermentation conditions were: 50ml liquid medium in a flask of 250ml,seed age 24h,inoculum 9%,initial pH value 9.0,culture temperature 35℃ and culture time 36h.Pectinase activity reached 311U/ml under the optimized medium and fermentation conditions.