African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12191

Full Length Research Paper

Combined amino acids modulation with H2O2 stress for glutathione overproduction in Candida utilis

Bin Wang1, Guobin Liang1, Quanfa Zhou1, Jianghui Xie2 and Yiwei Mo2*
1School of Chemistry and Environmental Engineering, Jiangsu Teachers University of Technology, Changzhou 213001, China. 2South Subtropical Crop Research Institute, Chinese Academy of Tropical Agricultural Science, Zhanjiang 524091, China.
Email: [email protected]

  •  Accepted: 22 July 2010
  •  Published: 31 August 2010

Abstract

Strategies of amino acids addition coupled with H2O2 stresses were developed for glutathione (GSH) overproduction in high cell density (HCD) cultivation of Candida utilis. Based on the fact that glycine shows two functions of promoting cells growth as well as GSH production, precursor amino acids modulations of feeding glycine at 4 mmol/l/h at exponential phase and adding precursor amino acids (glutamic acid 42 mmol/l, glycine 40 mmol/l, and cysteine 36 mmol/) at stationary phase were conducted. As a result, cell density reached 114.8 g/l at 45 h and glutathione yield of 2136 mg/l was achieved at 60 h, which was 12.5 and 90.2% higher than the control, respectively. Furthermore, the novel strategies of amino acids modulation combined with H2Oadditions (24 mmol/l at 21 h, 26 mmol/l at 29 h, 28 mmol/l at 37 h and 30 mmol/l at 45 h) were adopted to maximize glutathione production. Final glutathione yield reached 2448 mg/l after 60 h cultivation, suggesting the strategies developed as being feasible for GSH overproduction.

 

Key words: Amino acids, glutathione (GSH), high cell density (HCD) cultivation,Candida utilis, H2O2 stresses.

Abbreviation

PEP, Phosphoenolpyruvate; GSH, reduced glutathione; GSSG,oxidized glutathione; DCW, dry cell weight; HCD, high cell density cultivation.