Isolation and Identification of the most Producible Mold for Kojic Acid by the Molecular Method and Modify the Production Medium for Pure and High Yield of Crystals


Seventeen wild fungal isolates were tested for kojic acid production, nine of them were found kojic acid producer (53%), and the 4a isolate was the highest producer of kojic acid. Which diagnosed using microscopic procedure and at molecular level (using the internal transitional spacer ITS 1,4) and found to be A. oryzae and sequences of ITS were 548 sequences. Surface liquid cultures fermentation was used for determination of the optimal conditions for kojic acid production which were found to be, 8 days of fermentation period, pH 6 at 30 ˚C and at 100 g/L glucose as a carbon source, 2.5 g/L yeast extract and 0.1 g/L ammonium nitrate as nitrogen sources and 1 g/L disodium phosphate or potassium dihydrogene phosphate and with occasional shaking for four hours a day at 150 round/min. The isolate produced 60 g/L of kojic acid at yield of 0.78 g of kojic acid from 1 g glucose. Decreasing the added yeast extract to the production media to the lowest amount and commutating it by adding an inorganic nitrogen source caused an increase in the yield of kojic acid crystals to 58.28 %, the purified kojic acid isolated crystals gave 95% of correspondence ratio to the standard kojic acid crystals when they analyzed by using infrared spectroscopy.