Production of Polygalacturonase by Recombinant Aspergillus oryzae in Solid-State Fermentation Using Potato Pulp

The aim of this study was to produce valuable products from potato pulp, which is a byproduct of potato starch production and contains a high concentration of starch. We used the pulp as a substrate for polygalacturonase (PG) production in solid-state fermentation by a recombinant Aspergillus oryzae strain, PGB3. To generate PGB3, we constructed the PG gene (pgaB) overexpression vector pGBmR, and used that vector to transform the A. oryzae strain, RIB40. PGB3 carries a PG gene under control of the Taka-amylase gene promoter. When cultured in potato pulp solid medium, PGB3 grew more rapidly and produced 4.5 times more PG than RIB40. We observed maximum production (173 U/g) of PG after 2 days of culture of PGB3 in potato pulp solid medium. This high-level PG production from potato pulp demonstrates its potential as a useful substrate in fermentation.