Optimized conditions for high erythritol production by Penicillium sp KJ-UV29, mutant of Penicillium sp KJ81

To improve the erythritol productivity of Penicillium sp. KJ81, mutants were obtained using UV irradiation and NTG treatment. Among these mutants, Penicillium sp. KJ-UV29 revealed no morphological changes, yet was superior to the wild strain in the following three points: (1) Penicillium sp. KJ-UV29 produced more erythritol than the wild strain under the same conditions, (2) no foam was produced during cultivation, unlike the wild strain, and (3) the mutant produced a significantly lower amount of glycerol. Penicillium sp. KJ-UV29 produced as much as 15.1 g/L of erythritol, whereas the wild-type Penicillium sp. KJ81 only produced 11.7 g/L. Penicillium sp. KJ-UV29 only generated 6.1 g/L of glycerol, compared to 19.4 g/L produced by the wild strain. When investigating the optimal culture conditions for erythritol production by the mutant strain Penicillium sp. KJ-UV29, sucrose was identified as the most effective carbon source, and the mutant was even able to produce erythritol in a 70% sucrose-containing medium, although a 30% sucrose medium exhibited the highest productivity. The production of erythritol by Penicillium sp. KJ-UV29 was also significantly increased by the addition of ammonium carbonate, potassium nitrate, and sodium nitrate. Accordingly, under optimal conditions, Penicillium sp. KJ-UV29 produced 45.2 g/L of erythritol in a medium containing 30% sucrose, 0.5% yeast extract, 0.5% (NH4)(2)C2O4, 0.1% KNO3, 0.1% NaNO3, and 0.01% FeSO4 with 1 vvm aeration and 200 rpm agitation at 37degreesC for 7 days in a 5-L jar fermentor.