Hyperthermostable <i>Thermotoga maritima</i> xylanase XYN10B shows high activity at high temperatures in the presence of biomass-dissolving hydrophilic ionic liquids

Yu T., Anbarasan S., Wang Y., Telli K., Aslan A. S., Su Z., ...More

EXTREMOPHILES, vol.20, no.4, pp.515-524, 2016 (SCI-Expanded) identifier identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 20 Issue: 4
  • Publication Date: 2016
  • Doi Number: 10.1007/s00792-016-0841-y
  • Journal Name: EXTREMOPHILES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.515-524
  • Istanbul Kültür University Affiliated: No

Abstract

The gene of Thermotoga maritima GH10 xylanase (TmXYN10B) was synthesised to study the extreme limits of this hyperthermostable enzyme at high temperatures in the presence of biomass-dissolving hydrophilic ionic liquids (ILs). TmXYN10B expressed from Pichia pastoris showed maximal activity at 100 A degrees C and retained 92 % of maximal activity at 105 A degrees C in a 30-min assay. Although the temperature optimum of activity was lowered by 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), TmXYN10B retained partial activity in 15-35 % hydrophilic ILs, even at 75-90 A degrees C. TmXYN10B retained over 80 % of its activity at 90 A degrees C in 15 % [EMIM]OAc and 15-25 % 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM]DMP) during 22-h reactions. [EMIM]OAc may rigidify the enzyme and lower V (max). However, only minor changes in kinetic parameter K (m) showed that competitive inhibition by [EMIM]OAc of TmXYN10B is minimal. In conclusion, when extended enzymatic reactions under extreme conditions are required, TmXYN10B shows extraordinary potential.