Hydrolysis of soybean isoflavones by Debaryomyces hansenii UFV-1 immobilised cells and free β-glucosidase

Abstract

An intracellular β-glucosidase from Debaryomyceshansenii UFV-1 was produced in an YP medium with cellobiose as the carbon source. This enzyme was purified, characterised and presented a Mr of 65.15kDa. Yeast cells containing the intracellular β-glucosidase were immobilised in calcium alginate. The free β-glucosidase and immobilised cells containing the enzyme presented optima values of pH and temperature of 6.0 and 45°C and 5.5 and 50°C, respectively. The free enzyme maintained 62% and 47% of its original activity after 90days at 4°C and after 15days at room temperature, respectively. The immobilisation process resulted in higher enzyme thermostability at 45 and 50°C. Soy molasses treatment with the free enzyme and the immobilised cells containing β-glucosidase, for 2h at 40°C, promoted efficient hydrolysis of isoflavone glicosides to their aglycon forms. The results suggest that this enzyme could be used in the food industry, in the free or immobilised forms, for a safe and efficient process to hydrolyse isoflavone glycosides in soy molasses.

Immobilization of Glycoside Hydrolase Families GH1, GH13, and GH70: State of the Art and Perspectives

“…The entrapment in calcium alginate is the most frequently method used for β-glucosidase immobilization reported in the literature [70,95,131,132,133,134,135] (Table 3). This method showed good enzymatic recovered activities of 60% [134], 66% [136], and 73% [137].…”

“…This method showed good enzymatic recovered activities of 60% [134], 66% [136], and 73% [137]. However, when the whole cells from Debaryomyces hanseniiwere showing β-glucosidase activity were immobilized, the recovered activity was only 8% [133]. Although this immobilization method generally provides low mechanical strengths, the immobilization process produces enhanced thermal properties and higher optimum temperature usage [133,134,137], the possibility of reuse [134,137], and higher storage stability [133,134], compared to the free enzyme.…”

Isolation of Penicillium citrinum from Roots of Clerodendron cyrtophyllum and Application in Biosynthesis of Aglycone Isoflavones from Soybean Waste Fermentation

“…The hydrolysis yield of soybean waste extract (rich in isoflavone glycosides) to their aglycones by P. citrinum was estimated to be 98.7%, which is comparable to aglycone rates of 94.22 and 97.14% achieved by D. hansenii UFV-1 immobilized cells containing β-glycosidase and free enzyme, respectively [42], on soy molasses. However, our reported hydrolysis rate is higher than the rate of 93% achieved in deglycosylation of extracts of soybean flour and embryo in β-glucosidase derived from Paecilomyces thermophila J18 [43].…”

A Novel High Glucose-Tolerant β-Glucosidase: Targeted Computational Approach for Metagenomic Screening

“…In industrial bioconversion, reaction conditions, e.g., temperature and pH stability, substrate concentration, and inhibitors are remarkable factors that can affect the hydrolyzed quality of BGLs (Limauro et al, 2018;Cai et al, 2019). Regarding the industrial utilization of enzymes that often occurs at a specific range of temperature (50 • C) for an extended period and the fact that most of the BGLs with glucose resistance such as BGLs acquired from Debaryomyces hansenii and Thermoanaerobacterium aotearoense metagenome are heat-sensitive, the thermal stability of an enzyme is of great importance (Maitan-Alfenas et al, 2014;Yang et al, 2015). Thermostable enzymes offer numerous potential advantages in lignocelluloses bioconversion (Littlechild, 2015), such as increasing the reaction rate, the high solubility of the reactants, a lower risk of contamination, lowering the solution viscosity, and decreasing the cost of energy for cooling after thermal pretreatment (Seo et al, 2015;Zeiske et al, 2016).…”