Comparison of cell wall polysaccharides in Schizophyllum commune after changing phenotype by mutation

Abstract

The Agaricomycetes fungi produce various compounds with pharmaceutical, medicinal, cosmetic, environmental and biotechnological properties. In addition, some polysaccharides extracted from the fungal cell wall have antitumor and immunomodulatory actions. The aim of this study was to use genetic modification to transform Schizophyllum commune and identify if the phenotype observed (different from the wild type) resulted in changes of the cell wall polysaccharides. The plasmid pUCHYG-GPDGLS, which contains the Pleurotus ostreatus glucan synthase gene, was used in S. commune transformations. Polysaccharides from cell wall of wild (ScW) and mutants were compared in this study. Polysaccharides from the biomass and culture broth were extracted with hot water. One of the mutants (ScT4) was selected for further studies and, after hydrolysis/acetylation, the GLC analysis showed galactose as the major component in polysaccharide fraction from the mutant and glucose as the major monomer in the wild type. Differences were also found in the elution profiles from HPSEC and NMR analyses. From the monosaccharide composition it was proposed that mannogalactans are components of S. commune cell wall for both, wild and mutant, but in different proportions. To our knowledge, this is the first time that mannogalactans are isolated from S. commune liquid culture.

Key words
Genetic tools; fungus; mutant; cell wall; polysaccharides characterization