title: Enhancing the thermostability of α-L-rhamnosidase from Aspergillus terreus and the enzymatic conversion of rutin to isoquercitrin by adding sorbitol.
abstract: Thermally stable α-L-rhamnosidase with cleaving terminal α-L-rhamnose activity has great potential in industrial application. Therefore, it is necessary to find a proper method to improve the thermal stability of α-L-rhamnosidase.
  
  
  
  In this study, addition of sorbitol has been found to increase the thermostability of α-L-rhamnosidase from Aspergillus terreus at temperatures ranging from 65 °C to 80 °C. Half-life and activation free energy with addition of 2.0 M sorbitol at 70 °C were increased by 17.2-fold, 8.2 kJ/mol, respectively. The analyses of the results of fluorescence spectroscopy and CD have indicated that sorbitol helped to protect the tertiary and secondary structure of α-L-rhamnosidase. Moreover, the isoquercitrin yield increased from 60.01 to 96.43% with the addition of 1.5 M of sorbitol at 70 °C.
  
  
  
  Our findings provide an effective approach for enhancing the thermostability of α-L-rhamnosidase from Aspergillus terreus, which makes it a good candidate for industrial processes of isoquercitrin preparation.
authors.affiliation: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China.|College of Chemical Engineering, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Ge
authors.affiliation: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China.|College of Chemical Engineering, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China.
authors.forename: Anna
authors.initials: A
authors.lastname: Chen
authors.affiliation: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China.|College of Chemical Engineering, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Pei
authors.affiliation: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China. lg.zhao@163.com.|College of Chemical Engineering, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China. lg.zhao@163.com.
authors.forename: Linguo
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China.|College of Chemical Engineering, Nanjing Forestry University, 159 Long Pan Road, Nanjing, 210037, China.
authors.forename: Xianying
authors.initials: X
authors.lastname: Fang
authors.affiliation: Jiangsu Kanion Pharmaceutical Co., Ltd, 58 Haichang South Road, Lianyungang, 222001, Jiangsu Province, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Ding
authors.affiliation: Jiangsu Kanion Pharmaceutical Co., Ltd, 58 Haichang South Road, Lianyungang, 222001, Jiangsu Province, China.
authors.forename: Zhenzhong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Jiangsu Kanion Pharmaceutical Co., Ltd, 58 Haichang South Road, Lianyungang, 222001, Jiangsu Province, China. xw@kanion.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiao
authors.affiliation: International centre for bamboo and rattan, 8 FuTong East Street, Beijing, 100714, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Tang
mesh_terms: D001230:Aspergillus / Q000201:enzymology*; D004789:Enzyme Activation; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry*; D006026:Glycoside Hydrolases / Q000737:chemistry*; D011794:Quercetin / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D012431:Rutin / Q000737:chemistry*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D005656:Fungal Proteins; C016527:isoquercitrin; D012431:Rutin; D011794:Quercetin; D006026:Glycoside Hydrolases; C022525:alpha-L-rhamnosidase
keywords: Enzymatic conversion; Sorbitol; Thermostability; α-L-Rhamnosidase