Enhanced biocatalysis mechanism under microwave irradiation in isoquercitrin production revealed by circular dichroism and surface plasmon resonance spectroscopy

• Published in: Bioresource technology 2016-04, Vol.205, p.48-57
• Main Authors: Gong, An, Zhu, Dan, Mei, Yi-Yuan, Xu, Xiao-Hui, Wu, Fu-An, Wang, Jun
• Format: Article
• Language: English
• Subjects: Biocatalysis; Catalysis; Circular Dichroism; Enzymatic biocatalysis; Glycoside Hydrolases - metabolism; Glycoside Hydrolases - radiation effects; Hydrolysis; Isoquercitrin; Microwave irradiation; Microwaves; Quercetin - analogs & derivatives; Quercetin - metabolism; Rutin - metabolism; Surface Plasmon Resonance; Temperature
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2016.01.009

[Display omitted] •Microwave irradiation was firstly used in enzymatic synthesis of isoquercitrin.•Reaction time (10min) was greatly decreased to one sixty than that in a batch reactor.•Vm/Km under microwave irradiation was 17.49-fold higher than that in a batch reactor.•Secondary structure data of hesperidinase proved the higher affinity to rutin by CD.•SPR showed rutin had a higher affinity to hesperidinase under microwave irradiation. An efficient and rapid process for isoquercitrin production by hesperidinase-catalyzed hydrolysis of rutin was successfully developed under microwave irradiation detecting the affinity by circular dichroism (CD) and surface plasmon resonance (SPR) spectroscopy. A maximum isoquercitrin yield of 91.5±2.7% was obtained in 10min with the conditions of 10g/L hesperidinase, 2g/L rutin, 30°C and microwave power density 88.9W/L. Enzymatic reaction rate and Vm/Km in the microwave reactor were 6.34-fold higher than in a continuous flow microreactor and 1.24-fold higher than in a biphasic system. CD and SPR analysis results also showed that hesperidinase has a better selectivity and affinity (3.3-fold than in a batch reactor) to generate isoquercitrin under microwave irradiation. Microwave irradiation greatly improved the reaction efficiency and productivity, leading to a more positive economical assessment. The binding affinity indicates the presence of strong multivalent interactions between rutin and hesperidinase under microwave irradiation.