Improved beta-amylase production on molasses and sugar beet pulp by a novel strain Paenibacillus chitinolyticus CKS1

Abstract

Molasses and sugar beet pulp, by-products in sugar industry, are produced in large amounts annually which create disposal problems. High sugar content in sugar beet molasses enables its use for fermentations while sugar beet pulp represents an interesting cheap raw material source for enzyme production. beta-amylase production by a new strain Paenibacillus chitinolyticus CKS1 was performed using a molasses and sugar beet pulp. Two different pretreatments of SBP were investigated while scanning electron microscopy (SEM) showed immobilization of P. chitinolyticus CKS1 cells onto alkali treated SBP. The statistical model was design via Central Composite Design (CCD) under the Response Surface Methodology (RSM) using three variables (inoculum concentration, time of incubation and sugar beet pulp concentration) for obtaining maximum beta-amylase activity. An approximately 3.66-fold increase in beta-amylase production was achieved in the optimized medium as compared with the nonoptimized medium. A maximum beta-amylase production 2.237 U/ml was achieved under optimal conditions inoculum concentration 10%, incubation time 83.07 h and SBP concentration 3%. A high performance liquid chromatography showed that P. chitinolyticus CKS1 hydrolyzed starch to form maltose as a major product. These results indicate that beta-amylase production could be improved using these kind of processes. Also, taking into consideration cheap substrates, economic side of the process is justified.