Extracellular carbohydrate production by isolates of Postia (=Poria) placenta
J A Micales, A L Richter, T L Highley
A monokaryotic strain of Postia (=Poria) placenta, ME20, which is unable to degrade wood, also failed to produce extracellular polysaccharide when grown in liquid culture, regardless of carbon source or concentration. Other isolates of Postia placenta, including another monokaryon and a hybrid of this monokaryon with ME20, produced large quantities of this material. The polysaccharide consisted primarily of glucose upon acid hydrolysis and resembled the glucan reported in culture filtrates of other wood decay fungi. It was produced primarily during the logarithmic phase of growth. Isolate ME20 formed high levels of laminarinase and glucan-degrading enzymes compared to the other isolates; the glucan of ME20 may be prematurely degraded. This study supports the importance of the extracellular matrix in the wood-decay process.
Keywords: BROWN ROT; FUNGI; CARBOHYDRATE METABOLISM; GLUCAN; LAMINARINASE; GLUCANASE; ENZYME ACTIVITY; POSTIA PLACENTA; PROTEIN PRODUCTION