Influence of pH on Kojic Acid Fermentation by Aspergillus flavus

Abstract

Abstract:The influence of pH on kojic acid fermentation by Aspergillus flavus Link 44-1 in submerged fermentation and resuspended cell system was investigated separately. Although the highest growth in submerged fermentation was obtained at initial culture pH between 6 to 7, the optimum kojic acid production was achieved at initial culture pH 3. At initial culture pH 2, growth was greatly inhibited and kojic acid was not produced. In resuspended cell system using buffered glucose solution, in which the production of cell material was carried out at initial culture pH 3, the optimum kojic acid production was also obtained at pH 3. Kojic acid production in fermentation using 50 L stirred tank fermenter with pH control strategy (fermentation was started with pH 3 and without pH control during growth phase and culture pH was controlled at 3 during the production phase) was improved by about 20% as compared to fermentation without pH control. The maximum kojic acid concentration in fermentation with pH control strategy was 62.00 g/L and this gave yield and productivity of 0.516 g/g and 0.22 G/L h, respectively.

Screening and optimization of submerged fermentation of aspergillus species for kojic acid production

“…Highest obtained yield was 4 g/L at 30 0 C and lowest as 0.2 g/L at 40 0 C. A decrease in Kojic acid concentration with increase in temperature was observed, whereas, 28 0 C was found to be the best temperature by El-Aasar ( 2006) in A. oryzae. Same results are reported by Devi et al, (2014) and Rosfarizan et al, (2010) that an increase in temperature shows signi cant effect on yield of Kojic acid.…”

An In vitro Approach for Evaluating Antimicrobial Activity and Production of Kojic Acid by Aspergillus flavus Isolated from Karwar Region

“…Comparably, A. oryzae produces kojic acid at pH 4 73 , in contrast, the kojic acid values appeared in our investigation were not consistent with other reporters, in which the largest amount of kojic acid was obtained from glucose at very acidic pH (1.9 to 3.0) 74 . During growth progress at pH 4.5 to 6, the fungi use enzymes to convert glucose into kojic acid 36 . However, the growth of the fungi was continuous at pH between 2 and 3 the production of kojic acid appeared 75 .…”

“…Until now, an ample amount of kojic acid has been obtained with the glucose that was used as a carbon source. Most of the Aspergillus and Penicillium species are potent producers of Kojic acid 36 . Among Aspergillus species, Aspergillus flavus being attentive as the maximum producer of Kojic acid.…”

Penicillium and Aspergillus Species Characterization: Adaptation to Environmental Factors and Sensitivity to Aqueous Medicinal Plants Extracts

“…It has been revealed that temperature and pH are central criteria for understanding the fungal ecology Ahmed and Naresh [5]. Rosfarizan, et al [22] demonstrated that the highest metabolic activities and cellular growth of filamentous fungi (Aspergillus spp. and Penicillium spp.)…”