Hermanová Soňa, Zarevúcká Marie, Bouša Daniel, Pumera Martin, Sofer Zdeněk
Department of Polymers, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic.
Nanoscale. 2015 Mar 19;7(13):5852-8. doi: 10.1039/c5nr00438a.
The thermal and solvent tolerance of enzymes is highly important for their industrial use. We show here that the enzyme lipase from Rhizopus oryzae exhibits exceptionally high thermal stability and high solvent tolerance and even increased activity in acetone when immobilized onto a graphene oxide (GO) nanosupport prepared by Staudenmaier and Brodie methods. We studied various forms of immobilization of the enzyme: by physical adsorption, covalent attachment, and additional crosslinking. The activity recovery was shown to be dependent on the support type, enzyme loading and immobilization procedure. Covalently immobilized lipase showed significantly better resistance to heat inactivation (the activity recovery was 65% at 70 °C) in comparison with the soluble counterpart (the activity recovery was 65% at 40 °C). Physically adsorbed lipase achieved over 100% of the initial activity in a series of organic solvents. These findings, showing enhanced thermal stability and solvent tolerance of graphene oxide immobilized enzyme, will have a profound impact on practical industrial scale uses of enzymes for the conversion of lipids into fuels.
酶的热耐受性和溶剂耐受性对于其工业应用极为重要。我们在此表明，米根霉脂肪酶在固定于通过施陶登迈尔法和布罗迪法制备的氧化石墨烯（GO）纳米载体上时，表现出极高的热稳定性和溶剂耐受性，甚至在丙酮中活性增强。我们研究了酶的多种固定化形式：通过物理吸附、共价连接以及额外的交联。结果表明，活性回收率取决于载体类型、酶负载量和固定化程序。与可溶性脂肪酶（40℃时活性回收率为65%）相比，共价固定化脂肪酶对热失活表现出显著更好的抗性（70℃时活性回收率为65%）。物理吸附的脂肪酶在一系列有机溶剂中活性超过初始活性的100%。这些结果表明氧化石墨烯固定化酶的热稳定性和溶剂耐受性增强，将对酶在工业规模上将脂质转化为燃料的实际应用产生深远影响。
