Effect of polymeric additives, especially Junlon and Hostacerin, on growth of some basidiomycetes in submerged culture

Six species of the Agaricaceae, Coprinaceae, Cortinariaceae and Polyporaceae were caused to grow as finely divided mycelial suspensions in submerged culture by inclusion in the medium of 0.1−0.2% (w/v) polyacrylic acid or sodium polyacrylate. In the absence of polyacrylates, liquid cultures tended to produce large mycelial clumps whereas cultures containing polymer largely grew as dispersed hyphal filaments (Phanerochaete chrysosporium, Phlebia radiataand Phlebia gigantea) or formed numerous minute pellets (Bjerkandera adusta, Coprinus cinereus and Pleurotus ostreatus). Other polyacrylate salts and acrylamides were less effective in preventing mycelial aggregation and other polymers including alginate derivatives, sorbitans, cellulose and modified celluloses, carrageenan, polyvinyl alcohols and quaternary ammonium compounds were ineffective in promoting filamentous growth. Biomass yields were significantly increased by inclusion of Junlon PW110 (polyacrylic acid) or Hostacerin (sodium polyacrylate) in the medium; yield was doubled in many cases. Increases in yield were probably due to the filamentous cultures maintaining exponential growth for a longer period than when aggregates were formed but growth rates were also improved in medium containing the polymers. The optimum concentration of polymer depends on the species and the constitution of the growth medium; modification of the medium enabled C. cinereus to be grown with dispersed filamentous growth both in shake-flask and fermenter cultures.