Degradation of konjac glucomannan by Thermobifida fusca thermostable β-mannanase from yeast transformant

Published Date 

January 2016, Vol.82:1–6,

Doi:10.1016/j.ijbiomac.2015.10.008

Title 

Degradation of konjac glucomannan by Thermobifida fusca thermostable β-mannanase from yeast transformant

• Author 

• Cheng-Yu Chen ^a,b
• Yu-Chun Huang ^a
• Ting-Ya Yang ^a
• Jhen-Yi Jian ^a
• Wei-Lin Chen ^a,c
• Chao-Hsun Yang ^a,c,,

• aDepartment of Cosmetic Science, Providence University, Taichung 43301, Taiwan
• bGraduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan
• cDepartment of Applied Chemistry, Providence University, Taichung 43301, Taiwan

Received 5 January 2015. Revised 1 October 2015. Accepted 3 October 2015. Available online 22 October 2015.

Abstract

Native konjac glucomannan was used as the substrate for thermophilic actinomycetes, Thermobifida fusca BCRC19214, to produce β-mannanase. The β-mannanase was purified and five internal amino acid sequences were determined by LC-MS/MS. These sequences had high homology with the β-mannanase from T. fuscaYX. The tfm gene which encoded the β-mannanase was cloned, sequenced and heterologous expressed in Yarrowia lipolytica P01g expression system. Recombinant heterologous expression resulted in extracellular β-mannanase production at levels as high as 3.16 U/ml in the culture broth within 48 h cultivation. The recombinant β-mannanase from Y. lipolytica transformant had superior thermal property. The optimal temperature of the recombinant β-mannanase from Y. lipolytica transformant (pYLSC1-tfm) was 80 °C. When native konjac glucomannan was incubated with the recombinant β-mannanase from Y. lipolytica transformant (pYLSC1-tfm) at 50 °C, there was a fast decrease of viscosity happen during the initial phase of reaction. This viscosity reduction was accompanied by an increase of reducing sugars. The surface of konjac glucomannan film became smooth. After 24 h of treatment, the DPw of native konjac glucomannan decreased from 6,435,139 to 3089.

Keywords

• Thermobifida fusca
• β-Mannanase
• Konjac glucomannan
• Yarrowia lipolytica
• Heterologous expression

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• ⁎ 
  Corresponding author at: Department of Cosmetic Science, Providence University, Taichung 43301, Taiwan.

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