Characterization β-glycosidase of Tempeh from Rejected Edamame Soybean and Determination Method of Extracted Genistein by Conventional and Compared Using of Modern Method

Abstract

The exploration of natural active material became special attention in recent research dimensions, such as genistein. Tempeh made from rejected edamame soybean is known to have a β-glycosidase enzyme and can be used to increase the content of genistein. The result of early research by Wibisono gave the conclusion that identification by 16S rRNA for IS.5 as dominant bacterial and β-glycosidase enzyme producer on soymilk from tempeh was L. plantarum IMAU: 10246. The resulting research gave the conclusion that GC content of L. plantarum IMAU: 10246 ratio was 56,37 mol%, had log phase of the 25 – 30th, stationary phase in 35th with death log phase in 45 - 50th from optimum temperature levels. On the other result, this bacterial had optimum growth on 35 – 38°C, pH 5,0 – 5,5 with having μm value as 0,276/hour, saturation constantan (K8) was 0,051 g/l and growth yield (Y) with 0,311 g biomass/g substrate. The result showed that using ammonium sulfate 40% was resulting specific activity of the highest enzyme approximately 1,856 x 10−2 unit.mg−1. Using Sephadex C-50 had yielded the increasing of specific activity becoming 0.218 unit.mg−1. The result of the molecular of the enzyme showed 11.51 kDa and has an optimum temperature of 40°C (by activity 0,0550 unit), optimum pH 6,5 (0,0923 unit), and had Km and Vmax values are 2,572 mM and 4,276 U.mg−1. β-glycosidase can be inhabiting by CaCl2 > EDTA > NaCl > KCl and allegedly belong to family 1. The extraction method using ultrasound yielded 1,526 mg.g−1, increasing 15,51% higher than conventional extraction. Hydrolysis optimally needs duration for about 120 minutes on 50 ml water containing 5g powder of tempeh from rejected edamame soybean.