Production Of Alkaline Pectinase And Its Application In Fabric Pretreatment

The 22 strains producing alkaline pectinase were screened from soil and rotten fruits. A bacterial strain highly producing alkaline pectinase was obtained from the cutis of rotten apples. The Gram staining and spores staining showed that: Gram-positive, rod-shaped, for the majority of endospores. The bacterial strain was identified as Paenibacillus pabuli by Biolog , named as Paenibacillus pabuli WZ008 and preserved in China Center For Type Culture Collection (CCTCC), coded as CCTCC No.M207183. Such kind of strain producing alkaline pectinase have not been reported so far.The conditions of enzyme production of Paenibacillus pabli WZ008 were optimized by single factor experiment and response surface methodology. The optimal medium components were : wheat bran 1%, peptone 0.15%, CaCO₃ 0.5% , pectin 0.6%. The corresponding fermentation conditions were : initial pH 7.8, inoculation value 16%, 30 mL liquid medium in a flask of 500 mL , temperature 30℃and culture time 60 h .Alkaline pectinase activity could reach 47.90 U/mL under the optimal medium and condition. The characteristics of alkaline pectinase showed that: the optimum pH of enzyme was 9.6 and enzyme was stable in pH 9.6. The optimum temperature of enzyme was 60℃, but enzyme was more stable in 55℃. Both the metal ion Ca²⁺ and a kind of certain surfactant could enhance the alkaline pectinase activity.The process conditions for pretreatment of cotton fabric using self-made alkaline pectinase were investigated, and the results were compared with the traditional pretreatment process. The optimal conditions of enzymatic scouring were: enzyme dosage 100 U/g, bath ratio 1:10, time 120 min, initial pH 9.6, temperature 55℃. The results showed that the capillary effect of the treated fabric could reach 8.2 cm, the percentage of weight loss was 2.26% and the unsaturated polygalacturonic acid from fabric treatment fluid was 22.91μmol. Compared with the alkali scouring, the fabric handle was softer and the loss of fabric fiber was less. Moreover, the conditions of enzymatic scouring was milder, the water consumption was lower and environmental pollution was fewer. So enzymatic scouring has good industrial prospects.