This short communication reports that multiple genera within the Oomycetes synthesize and store a water-soluble beta-1,3-glucan in their cytoplasm. Researcher S. Faro investigated eight strains representing various oomycete genera, including Achlya, Saprolegnia, Dictyuchus, Isoachlya, Thraustotheca, and Pythium species. Mycelia were cultured in nutrient media, harvested at appropriate growth stages, and glucan was extracted using phenol extraction methodology. Infrared spectroscopy analysis revealed that the extracted polysaccharides from all organisms examined were water-soluble and possessed infrared spectra identical or very similar to previously characterized beta-1,3-glucans from Phytophthora cinnamomi and Achlya species. The findings suggest this polysaccharide may be a characteristic feature common and unique to the Oomycetes phylogenetic group. Although not all oomycete orders were examined, the results indicate that members of Saprolegniaceae and Pythiaceae families all synthesize this cytoplasmic glucan, supporting the hypothesis that this compound is widespread throughout the division.

Key findings

• Multiple oomycete genera including Saprolegnia, Dictyuchus, and Pythium species synthesize and store water-soluble beta-1,3-glucan in their cytoplasm
• Infrared spectroscopy confirms identical polysaccharide composition across examined oomycete strains
• The water-soluble beta-1,3-glucan appears to be a characteristic feature common and potentially unique to the Oomycetes phylogenetic group
• Glucan extraction yields decreased with prolonged fungal growth, possibly due to utilization as an endogenous carbon source during sexual reproduction