Hydrolysis of soy isoflavone glycosides by recombinant β-glucosidase from hyperthermophile Thermotoga maritima

Abstract

A recombinant Thermotoga maritima beta-glucosidase A (BglA) was purified to homogeneity for performing enzymatic hydrolysis of isoflavone glycosides from soy flour. The kinetic properties K(m), k(cat), and k(cat)/K(m) of BglA towards isoflavone glycosides, determined using high-performance liquid chromatography, confirmed the higher efficiency of BglA in hydrolyzing malonylglycosides than non-conjugated glycosides (daidzin and genistin). During hydrolysis of soy flour by BglA at 80 degrees C, the isoflavone glycosides (soluble form) were extracted from soy flour (solid state) into the solution (liquid state) in thermal condition and converted to their aglycones (insoluble form), which mostly existed in the pellet to be separated from BglA in the reaction solution. The enzymatic hydrolysis in one-step and two-step approaches yielded 0.38 and 0.35 mg genistein and daidzein per gram of soy flour, respectively. The optimum conditions for conversion of isoflavone aglycones were 100 U per gram of soy flour, substrate concentration 25% (w/v), and incubation time 3 h for 80 degrees C.

High production of succinyl isoflavone glycosides by Bacillus licheniformis ZSP01 resting cells in aqueous miscible organic medium

“…Soy isoflavone glycosides (daidzin, genistin, malonylgenistin, and malonyldaizin) are the most predominant isoflavones in the soybean flour crude extract [20]. However, daidzin, genistin, daidzein, and genistein are the major forms of isoflavones in steamed soybeans in which most of acetylglycosides and malonylglycosides have been converted to glycosides or aglycones [21].…”

Characterization of a β-glucosidase from Sulfolobus solfataricus for isoflavone glycosides

“…The activities of b-glucosidases from A. oryzae (Kaya et al 2008), B. subtilis (Kuo and Lee 2008), D. nigrescens (Chuankhayan et al 2007), P. thermophila (Yang et al 2009), Pseudomonas sp. (Yang et al 2004), and T. maritima (Xue et al 2009) were maximal at 55, 45, 65, 75, 40, and 70°C, respectively. Thus, temperature for the maximal activity was highest.…”

“…Isoflavone aglycones typically exhibit higher pharmaceutical activities than isoflavone glycosides, and the enzymatic hydrolysis of the latter to create the former has been previously investigated using b-glucosidases from the microorganisms Aspergillus oryzae (Kaya et al 2008;Horii et al 2009), B. subtilis (Kuo and Lee 2008), Bifidobacterium lactis, Lactobacillus acidophilus, L. casei (Donkor and Shah 2008), Escherichia coli (Ismail and Hayes 2005), Paecilomyces thermophila (Yang et al 2009), Pseudomonas sp. (Yang et al 2004), and Thermotoga maritima (Xue et al 2009), and the leguminous plants Dalbergia cochinchinensis, D. nigrescens (Chuankhayan et al 2007), Glycine max (soybean), and the commercial almond (Hsieh and Graham 2001). However, the relatively low conversion yields and productivities of these enzymes render them of little commercial value.…”

“…However, all of the b-glucosidases from D. nigrescens, D. cochinchinensis(Chuankhayan et al 2007), P. thermophila(Yang et al 2009), Pseudomonas sp (Yang et al 2004),. and T. maritima(Xue et al 2009) exhibited the highest activity for genistin. The k cat /K m values for S. solfataricus b-glucosidase followed the order daidzin (5065 mM -1 s -1 ) [ glycitin (3724 mM -1 s -1 ) [ genistin (3106 mM -1 s -1 ), whereas the substrate affinity followed the ).…”

Production of Liquiritigenin with Cell-based Biotransformation and Its Anti-Aging Activity

“…Therefore, the hydrolysis of the isoflavone glucosides is necessary to increase their absorption in the intestine and promote health related beneficial effects [9,10]. So, much effort has been devoted to develop an efficient and simple enzymatic bioconversion method instead of the harsh chemical treatment [9,[11][12][13].…”