A New Enzyme Preparation for Reducing the Viscosity of Whole-Grain Rye Extracts

Abstract

New recombinant strains based on the lower fungus Penicillium canescens are engineered to produce an extracellular enzyme complex that contains a homologous endo-1,4-β-xylanase E (XylE, EC 3.2.1.8). Expression of the gene encoding XylE is controlled by the promoter of the xylA gene, which encodes endo- 1,4-β-xylanase A. Comparative analysis of enzyme preparations (EPs) isolated from the culture liquid of the host strain (Penicillium canescens RN3-11-7) and the new recombinant P. canescens strains of the XylE series is performed. The specific activity of the EPs against a specific substrate (birch glucuronoxylan) is studied, and the qualitative and quantitative composition of the new EPs XylE-B5 and XylE-C1, as well as the RN3 EP from the host strain, is determined. The decrease in the reduced viscosity of native (not subjected to thermal inactivation) aqueous extracts of rye treated with XylE-B5 EP was double that in the case of treatment with RN3 EP, due to high content of inhibition-resistant XylE in the new EPs.