Role of phenolic compounds in the regulation of citric acid production by Aspergillus oryzae NCIM-929

The present study investigates the regulatory influence of phenolic phytochemicals on citric acid production by Aspergillus oryzae NCIM929. Phenolic compounds are known to act as redoxactive molecules that can modulate key metabolic pathways in fungi. Selected phenolics, including catechol, ferulic acid, and coumarin, were supplemented into the fermentation medium to assess their impact on biomass formation, citric acid yield, and metabolic enzyme activity. The results demonstrated that low to moderate concentrations of specific phenolics significantly enhanced citric acid accumulation, likely through modulation of the tricarboxylic acid (TCA) cycle and reduction of byproduct formation such as oxalic acid. Enhanced activity of citrate synthase and reduced activity of aconitase were observed in phenolic-treated cultures, indicating a metabolic shift favoring citrate accumulation. These findings suggest that phenolic compounds act as metabolic effectors influencing oxidative balance and enzymatic regulation in A. oryzae, thereby providing a novel biochemical strategy for improving citric acid biosynthesis in industrial fermentation processes. In the present communication efficacy of phenolic compounds, i.e.;5,7-dihydroxy4-phenylcoumarin on citric acid production by Aspergillus oryzae NCIM-929 has been assessed. It has been found that the compound under trial has slight stimulatory impact on the production of citric acid and enhances the yield of citric acid to an extent of 6.592% higher in comparison to control,i.e.; 7.539 g/100mL under the optimized conditions,ie;molasses solution 24% (w/v), pH 2.0,temperature 270C and incubation period of 11days along with some other significant rich ingredients required by the Aspergillus oryzae NCIM-929.