Biology subjects

Fry, S. C.

Publications and source records attributed to Fry, S. C..

3 recordsLinked to original sources

bioRxiv2026

Comparative sugar utilisation and metabolism of mannose as co-substrate indicate flexibility in carbon metabolism in anaerobic gut fungi

Anaerobic gut fungi (AGF) are key degraders of plant biomass in ruminants, yet there is limited knowledge of how AGF respond to mixtures of plant-derived sugars. Here, we assessed monosaccharide and disaccharide utilisation by Neocallimastix frontalis CoB3, Caecomyces communis SHB, and Piromyces edwardsiae SHC, which are abundant in the rumen microbiome. While all AGF isolates shared a core set of sugars that supported growth, they had different hierarchies of uptake. Co-substrate experiments using glucose and lignocellulose-derived sugars revealed species-specific responses, with N. frontalis displaying a novel concentration-dependent co-utilisation of glucose and mannose, whereas growth of P. edwardsiae was inhibited under the same conditions, and C. communis exhibited growth inhibition in glucose and xylose co-substrate cultures. Together, these findings demonstrate functional diversity in monosaccharide and disaccharide metabolism amongst the AGF investigated here. Understanding such sugar utilisation phenotypes provides a foundation for evaluating AGF isolate suitability for lignocellulosic biomass valorisation.

microbiology↗

bioRxiv2026

Sugar-mediated inhibition of growth and lignocellulose degradation in anaerobic gut fungi revealed using cellulose filter paper

Anaerobic gut fungi (AGF) are central to the degradation of plant material in the digestive systems of herbivores. However, how their environment influences their colonisation and degradation of complex biomass is unclear. Here, cellulose filter paper was used as a simplified model of the plant cell wall to investigate how the presence of free sugars in the rumen can affect AGF growth and degradative responses of phylogenetically distinct AGF isolates. From this, galactose was revealed to be inhibitory to both Neocallimastix frontalis and Caecomyces communis, and mannose inhibitory to C. communis. Complete inhibition of C. communis growth was conserved when galactose and mannose were added in their polymeric forms, whereas in contrast, N. frontalis growth was unaffected. This indicates, depending on the AGF isolate, the presence of free sugars and their polymeric form may influence AGF growth through regulatory and metabolic interactions - even if the sugar cannot be utilised for growth as the sole substrate. Collectively, this work highlights the functional diversity in AGF carbohydrate responses and the need for greater understanding of their metabolic regulation for applications in lignocellulosic bioconversion and ruminant nutrition.

microbiology↗

bioRxiv2022

Cell walls are dynamically O-acetylated in the green seaweed, Ulva compressa

We report that cell wall polymers in the chlorophyte algae may be modified by O-acetylation. The importance of cell wall modifications in the green algae is not well understood, although similar modifications play key roles in land plants by modulating the properties of cell wall carbohydrate polymers. Using a combination of biophysical (Fourier-transform infrared and cross-polarisation heteronuclear correlation nuclear magnetic resonance spectroscopy), biochemical (thin-layer chromatography) and molecular approaches (yellow fluorescent protein-tagged transgene localisation), we show that the extractable ulvan fractions of Ulva compressa cell walls contain O-acetyl sidechains, we demonstrate that acetylation is dynamic and decreases reversibly in response to metal-induced stress, we note interactions between acetyl and borate sidechains and we locate two candidate genes that, together, may encode an acetyltransferase. We therefore propose that O-acetylation of ulvan residues is involved in the normal cell wall physiology of at least some chlorophyte algae. To the best of our knowledge, this is the first demonstration of O-acetyl sidechains in green algal cell wall polymers, and of reversible changes in algal cell wall polymer modification in response to stress.

cell biology↗