Microbial conversion of L-ascorbic acid to L-erythroascorbic acid.

We found that a strain of Penicillium sp. effectively converted L-ascorbic acid to a five-carbon analog, which was identified as L-erythroascorbic acid based on spectroscopic analysis. The conversion was achieved by growing culture or washed mycelia, with a yield of approximately 20-30% (mol/mol). The processes for the bioconversion and purification of the product are described.