Exopolysaccharides, proteins and lipids in Pleurotus pulmonarius submerged culture using different carbon sources.

For many years mushrooms have been consumed and appreciated by their nutritional value, and medicinal properties. The traditional mushroom cultivation takes too long and the macrofungi biotechnology has not been explored in its full potential yet. The goal of this work was to observe if different carbon sources could improve the yield and diversify fungi nutrient composition in submerged culture. Pleurotus pulmonarius mycelia and exopolysacharide productions were evaluated using glucose, galactose, xylose and arabinose. The mycelia yield varied depending on the culture medium, and galactose showed to be the best carbon source to produce EPS. Samples that showed the highest protein contents were grown with xylose (19.44%) and arabinose (26.05%). Furthermore, the biomass cultivated with these carbohydrates and with galactose showed five essential amino acids. All cultured biomass showed low lipid contents (∼1%), being composed mainly of unsaturated fatty acids. All EPS fractions showed as main structures glucans and mannogalactans.

Some biomolecules and a partially O-acetylated exo-galactomannan containing ß-Galf units from pathogenic Exophiala jeanselmei, having a pronounced immunogenic response.

The pathogenic fungus Exophiala jeanselmei (Ej4) was grown in submerged MM medium, glucose being consumed after six days with maximum biomass and EPS production. Cells were extracted with CHCl3-MeOH (2:1, v/v) yielding a product containing 10% lipid, with high levels of unsaturated C(18:1) (43.6%) and C(18:2) (21.0%), 2D-TLC showed the presence of PE (17.7%), PS (11.6%), PC (35.8%), PI (1.2%) and lyso-phospholipids, LPE (10.7%), LPC (2.0%), PA (10.4%), cardiolipin (10.5%) and glucosyl-ceramide. Analysis of EPS-1 (120 kDa) showed a galactomanan, containing a main chain of Manp-(1→2) (24.2%), substituted by side chains containing terminal Galf (16.8%) and Manp (3.5%) and acetyl groups attached at O-6 of terminal Galf. An immune response against antigens was obtained using Balb/C mice. Anti-EPS-1 antibodies recognized purified fraction containing cellular walls very titer and higher than 1:20,000 for EPS. The studied biomolecules showed biotechnological potential and point to important perspectives in diagnosis of fungi and immunomodulatory products.