Linamarase Enzyme from Lactobacillus delbrueckii NRRL B-763: Purification and Some Properties of a β-Glucosidase

Abstract

Some biochemical properties and purification of linamarase enzyme from Lactobacillus delbrueckii NRRL B-763 were studied. The crude enzyme was used to detoxify cassava flour cyanide and samples of 150 µm particle size treated with the crude enzyme showed a reduction from 2.1 mg HCN/10g sample to 0.11 mg HCN/10 g sample after 20 h (95% reduction). Untreated control samples of 0.5 mm particle size showed a reduction from 2.1mg HCN/10 g sample to 1.98 mg HCN/10 g sample after 40 h (5.7% reduction). The enzyme was purified 33 fold with a 40% yield through a series of four steps namely, ammonium sulphate precipitation, acetone precipitation, ion exchange chromatography and gel filteration chromatograrphy using Sephadex G-200. The purified enzyme showed maximum activity at pH 4.5. The enzyme showed 100% stability at the pH range of 5.0 and 6.0. Maximum activity of the enzyme was observed at a temperature of 50 o C and maximum stability at a temperature range of 40 and 50 o C. The approximate enzyme molecular weight was estimated to be 56