PHYSIOLOGICAL-STUDIES OF EXOPOLYSACCHARIDE PRODUCTION FROM THE BASIDIOMYCETE-PLEUROTUS SP FLORIDA

Pleurotus florida was grown in shake-flask culture in liquid media con taining different carbon and nitrogen sources. Changes in carbon and n itrogen supplies affected the amount of biomass and production of exoc ellular polysaccharide in the medium. Glucose was the preferred carbon source (20-60 g l(-1)) rather than sucrose, galactose, lactose, or xy lose, for optimum exopolysaccharide production (0.5 gl(-1)) which was stimulated by a high C:N ratio. Nitrogen-limited cultures (0.1 gl(-1) ammonium tartrate) produced the most exopolysaccharide. Growth of P. f lorida in reactor cultures produced low yields of exopolysaccharide (0 .29 gl(-1)), which was partly explained by the poor mass transfer rate s associated with growth of mycelial pellets surrounded by adherent po lysaccharide.