Cross-linking of Fungal β-glucosidase on AlO Nanocrystals Synthesized Using Cajanus Cajan L. Millsp. Extracts for in Suit Genistein Manufacture

This present study deals with the cross-linking of fungal β-glucosidase on AlO nanocrystals (NCs) synthesized in C. cajan for in-suit genistein production. The Cajanus cajan leaves were dried and used to prepare their extract at 65 °C by agitation for 30 min. For enzyme production under submerged culture, 50 mL of medium at pH 8.6 with an inoculum volume of 2 mL; was incubated for 72 h with optimized parameters at 30 °C. The AlO NCs were synthesized by adding 30 mM AlNO to 25 mL of leaf extract with NaOH at 65 °C for 50 min which enhanced the β-glucosidase specific activity when immobilized. Genistein by biotransformation was obtained using both free (0.67 ± 0.42 mg/mL) and AlO immobilized β-glucosidase (1.3 ± 0.66 mg/mL) for 48 h. The substrate level and enzyme concentration were 2.5 and 1 mL respectively. The UV visible spectra for leaf extract; free and cross-linked β-glucosidase and AlO NCs were at 225, 235, 300, and 210 nm. The bands for AlO NCs were achieved at 500-750 cm which showed the FTIR analysis to check the change in functional groups of free and AlO cross-linked β-glucosidase. In XRD analysis, peaks depicted the crystalline structure of AlO NCs ranging from 10-50°. The size of NCs was confirmed by using different magnifications (1.01, 2.00, 3.00, 5.00, 7.02, and 10 K X) of SEM images obtained. For zeta potential measurements, the peak was obtained at -21.0 mV.