Influences of phenolic compounds on citric acid productivity by Aspergillus niger in stirred fermentor
Bekir Sıtkı ÇEVRİMLİ1 · Ergin KARİPTAŞ*#2 · Ahmet YAŞAR3 · Mustafa YİĞİTOĞLU4
of Chemistry, Atatürk Vocational School, Gazi University, Ankara, Turkey
*Corresponding author: email@example.com
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.
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.