Production Of Alkaline Pectinase By Deep Submerged Fermentation And Studies On Its Application In Pretreatment Process Of Cotton Fabric

In this paper,production process of alkaline pectinase using a laboratory strain?Paenibacillus pabli WZ008?by a 15L or 7L ventilating mechanical stirring fermentor was studied.The variation laws of four fermentation parameters?biomass,total sugar content,pH,enzyme activity?were obtained.The fermentation conditions were:inoculum concentration 10%,broth content 70%,stirring speed 300rpm,ventilatory volume 25NL/min,cycle of fermentation 40h.Under this condition,the final enzyme activity was 38.9U/ml?total volume of broth was 6.7L?, total enzyme amount was 260630U,production intensity was 6515.8U/h and the and the volume production rate of enzyme was 972.5U/?L·h?. Crude enzyme powder was gained by fractional salting of ammonium sulfate?50%?80%?and subsequent vacuum freeze-drying.Using the crude enzyme,the effects of addition of different emulsifiers during cotton fabric bioscouring have been studied.The results showed that the emulsifier can markedly improved enzyme scouring effects.Three prominent emulsifiers have been selected: Tween-80,Span-20,DATEM.Taken three emulsifiers and alkaline pectinase as four factors,a four factors and three levels orthogonal experiment was carried.Analysis of orthogonal experiment results and comprehensive account of the cost,the better compound enzymes were: alkaline pectinase 60U/g,Tween-80 0.6%,Span-20 0.6%,DATEM 0.15%. Finally,the comparison between the enzyme treatment and the alkali treatment has been done.It showed that the compound enzymes have flourishing application in the cotton fabrics pretreatment due to its gentle reaction and non-pollution.Because of the poor thermal stability of the alkaline pectinase,in order to decrease the cost of its industrial application,its thermal stability must be increased.Therefore,in this paper,the effects on alkaline pectinase activity and thermal stability of carboxylate,polyhydroxy compound,carbohydrate and metal ions were studied.Sodium acetate could increase enzyme thermal stability markedly,and Ca²⁺could increase enzyme activity,hence sodium acetate and Ca²⁺were selected as the enzyme protectice agents.Finally,the comparison of thermal stability parameters?such as E_a?T_m and so on?between the enzyme with protective agents and without was carried.The activity and thermal stability of enzyme with protective agents were improved evidently.