Immobilization of Thermoalkalophilic Lipase From Bacillus Atrophaeus Fshm2 on Amine-Modified Graphene Oxide Nanostructures: Statistical Optimization and Its Application for Pentyl Valerate Synthesis Publisher Pubmed



Ameri A¹ ; Shakibaie M^{1, 2} ; Khoobi M³ ; Faramarzi MA⁴ ; Ameri A¹ ; Forootanfar H^{2, 6} Show Affiliations
Source: Applied Biochemistry and Biotechnology Published:2020

Abstract

Synthesis of (3-aminopropyl) triethoxysilane (APTES)-functionalized graphene oxide (GO) nanosheets, statistical optimization of conditions for immobilization of Bacillus atrophaeus lipase (BaL) on as-synthesized support, and application of the immobilized BaL for esterification of valeric acid were carried out in this investigation. The optimum specific activity of the immobilized BaL (81.60 ± 0.28 U mg−1) was achieved at 3 mg mL−1 of GO-NH2, 50 mM of phosphate buffer, pH 7.0, 60 min sonication time, 100 mM glutaraldehyde, 25 U mL−1 of enzyme, and 8 h immobilization time at 4 °C. The immobilized BaL retained about 90% of its initial activity after 10 days of storage. Moreover, about 70% of the initial activity of the immobilized BaL was retained after 10 cycles of application. The results of esterification studies exhibited that maximum pentyl valerate synthesis using the free BaL (34.5%) and the immobilized BaL (92.7%) occurred in the organic solvent medium (xylene) after 48 h of incubation at 60 °C. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.