Protopectinase production by Paenibacillus polymyxa Z6 and its application in pectin extraction from apple pomace

摘要

Paenibacillus polymyxa Z6 was screened as protopectinase (PPase) producing strain and its PPasernactivity was 44.4 U/mL. The factors influencing PPase production were identified by a two-levelrnPlackett–Burman design with seven variables. The results indicated that Ca~(2+) concentration, fermentationrntime, and temperature were the most influential factors on the PPase production,rnwhich were applied in the Box–Behnken design. The predicted maximum PPase activity was 219rnU/mL and the experimental maximum PPase activity was 221 U/mL, under the predicted optimumrnconditions, 170 mg/L Ca~(2+), 27℃, and 29 hr of fermentation. The present PPase was composedrnof both type-A PPase, polygalacturonase; and type-B PPase, arabinanase, and rhamnogalacturonase.rnFinally, the PPase was applied for the pectin extraction from apple pomace and achieved anrnaverage yield of 11.9% with properties like 8.5% moisture content, 1.6% ash content, 3.8 mPa·Srnviscosity, and pH 6.1 of 1% solution.