Application of bubble column fermenters to submerged culture of Schizophyllum commune for production of L-malic acid

To investigate the applicability of bubble column fermenters to the submerged culture of mushroom mycelia, cultivation of Schizophyllum commune IFO-4928 for production of L-malic acid was carried out using a standard bubble column and an external-loop airlift column. Maximum yields of L-malic acid were attained at a superficial air velocity of 0.7 cm/s for the standard bubble column and 1.7 cm/s for the external-loop airlift column. The optimum temperature was 27 degrees C for both types of column, and the optimum concentrations of both calcium carbonate and glucose were 50 g/l. The yield of L-malic acid under opimum conditions for the airlift column was larger than for the standard bubble column. From the comparison of the production rates of L-malic acid in flask culture, a jar fermenter, an airlift column, and a standard bubble column, the airlift bubble column was found to be most suitable for the culture of S. commune for L-malic acid production.