title: Using ionic liquids in whole-cell biocatalysis for the nucleoside acylation.
abstract: BACKGROUND
  The use of biocatalysts has become an increasingly attractive alternative to traditional chemical methods, due to the high selectivity, mild reaction conditions and environmentally-friendly processes in nonaqueous catalysis of nucleosids. However, the extensive use of organic solvents may generally suffer from sever drawbacks such as volatileness and toxicity to the environment and lower activity of the biocatalyst. Recently, ionic liquids are considered promising solvents for nonaqueous biocatalysis of polyhydroxyl compounds as ILs are environmental-friendly.
  
  
  RESULTS
  In this research, we developed new IL-containing reaction systems for synthesis of long chain nucleoside ester catalyzed by Pseudomonas fluorescens whole-cells. Various ILs exerted significant but different effects on the bio-reaction. And their effects were closely related with both the anions and cations of the ILs. Use of 10% [BMI][PF6]/THF gave high reaction efficiency of arabinocytosine laurate synthesis, in which the initial rate, product yield and 5'-regioselectivity reached 2.34 mmol/L·h, 81.1% and >99%, respectively. Furthermore, SEM analysis revealed that ILs can alter the cell surface morphology, improve the permeability of cell envelopes and thus facilitate the mass transfer of substrates to the active sites of cell-bound enzymes.
  
  
  CONCLUSIONS
  Our research demonstrated the potential of ILs as promising reaction medium for achieving highly efficient and regioselective whole-cell catalysis.
authors.affiliation: State Key lab of Pulp & Paper making Engineering, South China University of Technology, Guangzhou, 510641, China. 274064640@qq.com.|College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510641, China. 274064640@qq.com.
authors.forename: Meiyan
authors.initials: M
authors.lastname: Yang
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510641, China. yee36@qq.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510641, China. urbanfashion365@hotmail.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lian
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510641, China. xflibio@scut.edu.cn.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key lab of Pulp & Paper making Engineering, South China University of Technology, Guangzhou, 510641, China. 303515592@qq.com.|College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510641, China. 303515592@qq.com.
authors.forename: Yao
authors.initials: Y
authors.lastname: Ren
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510641, China. meiyan000000@163.com.
authors.forename: Furao
authors.initials: F
authors.lastname: Lai
authors.affiliation: State Key lab of Pulp & Paper making Engineering, South China University of Technology, Guangzhou, 510641, China. zhaoguanglei@gmail.com.|College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510641, China. zhaoguanglei@gmail.com.
authors.forename: Guanglei
authors.initials: G
authors.lastname: Zhao
mesh_terms: D000215:Acylation; D002384:Catalysis; D052578:Ionic Liquids / Q000737:chemistry*; D009705:Nucleosides / Q000737:chemistry* / Q000378:metabolism; D011551:Pseudomonas fluorescens / Q000737:chemistry* / Q000378:metabolism
chemical_list: D052578:Ionic Liquids; D009705:Nucleosides