Effective valorisation of barley bran for simultaneous cellulase and β-amylase production by Paenibacillus chitinolyticus CKS1: Statistical optimization and enzymes application

Abstract

The agricultural raw industry generates large amounts of annually by--products that create disposal problems. Hitherto, there have been no reported papers about the simultaneous production of cellulase and β-amylase from these raw materials using Paenibacillus sp. that would reduce the costs. Thus, in this paper simultaneous cellulase (CMC-ase and avicelase) and β-amylase production using barley bran and the application of the natural isolate Paeni­bacillus chitinolyticus CKS1 and potential enzymes in the hydrolysis process was studied. Response surface methodology was used to obtain the maximum enzyme activity (CMC-ase 0.405 U mL-1, avicelase 0.433 U mL-1 and β-amyl­ase 1.594U mL-1). Scanning electron microscopy showed degradation of the lignocellulosic–starch structure of barley bran after fermentation. The CKS1 bacterial supernatant, which contains cellulases and β-amylase, could hydro­lyze cotton fibres and barley bran, respectively. The main products after enz­ym­atic hydrolysis of cotton fibres and barley bran, glucose (0.117 g gmat-1) and maltose (0.347 g gmat-1), were quantified by high performance liquid chromato­graphy (HPLC). The produced enzymes could be used for hydrolysis of cotton fabric and barley bran to glucose and maltose, respectively. Application of simultaneous enzymes production using an agricultural by-product is econo­m­ically and environmentally accepted and moreover, valuable biotechnological products, such as glucose and maltose, were obtained in this investigation.