In a new approach to microbial gallic acid production by Aspergillus fischeri MTCC 150, 40gL-1 of tannic acid was added in two installments during the bioconversion phase of the process (25gL-1 and 15gL-1 at 32 and 44h respectively). The optimum parameters for the bioconversion phase were found to be temperature: 35ºC, pH: slightly acidic (3.3-3.5), aeration: nil and agitation: 250 rpm. A maximum of 71.4% conversion was obtained after 71h fermentation with 83.3% product recovery. The yield was 7.35 g of gallic acid per g of biomass accumulated and the fermenter productivity was 0.56 g of gallic acid produced per liter of medium per hour.
tannase; gallic acid; tannic acid; Aspergillus fischeri
