Environmental Biotechnology
  Biotechnology Industry
Electronic Journal of Biotechnology ISSN: 0717-3458 Vol. 13 No. 6, Issue of November 15, 2010
© 2010 by Pontificia Universidad Católica de Valparaíso -- Chile Received November 2, 2009 / Accepted June 1, 2010
DOI: 10.2225/vol13-issue6-fulltext-1  

Influences of phenolic compounds on citric acid productivity by Aspergillus niger in stirred fermentor 

Bekir Sıtkı ÇEVRİMLİ1 · Ergin KARİPTAŞ*#2 · Ahmet YAŞAR3 · Mustafa YİĞİTOĞLU4

1Department of Chemistry, Atatürk Vocational School, Gazi University, Ankara, Turkey
2Department of Biology, Faculty of Sciences and Arts, Ahi Evran University, Kirsehir, Turkey
3Department of Chemistry, Faculty of Sciences and Arts, Gazi University, Ankara, Turkey
4Department of Chemistry, Faculty of Sciences and Arts, Kirikkale University, Kirikkale, Turkey

*Corresponding author: ekariptas@ahievran.edu.tr

Financial support: This work was financially supported by the Gazi University Research Fund.

Keywords: A. niger, citric acid, fermenter, toxic chemicals (phenols).

Present address: #Department of Biology, Faculty of Sciences and Arts, Ahi Evran University, Kirsehir, Turkey.

Abstract   Full Text

Influences of phenol, α-naphtol and β-naphtol, which are toxic chemicals, on citric acid biosynthesis and biomass in the artificial culture setting of Aspergillus niger using batch fermenter are examined in the most favorable fermentation conditions, and a model is proposed. Addition of certain concentrations of phenol, α-naphtol and β-naphtol to the culture increases the citric acid production. According to this model, maximum citric acid concentration is 48.3 g L-1 in a culture that does not contain any toxic chemicals, whereas the maximum concentrations obtained in cultures containing 25 mg L-1 phenol, 25 mg L-1 alpha-naphtol and 15 mg L-1 beta-naphtol are 62.5 g L-1, 78.1 g L-1 and 86.0 g L-1, respectively. Moreover, addition of toxic chemicals to the culture reduces fermentation time by 24 hrs.

Supported by UNESCO / MIRCEN network