Biology subjects

Matthews, J. L.

Publications and source records attributed to Matthews, J. L..

4 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↗

bioRxiv2025

Lipid nanoparticle supplementation enhances host metabolism in a model symbiotic cnidarian

Stable cnidarian-dinoflagellate symbiosis provides the trophic foundation of coral reef ecosystems. Understanding nutrient exchange underpinning this symbiosis grows increasingly urgent as reefs face accelerating threats from climate change, and the need for time-critical interventions to improve coral health via aquaculture. Lipid nanoparticles (LNPs), widely used as delivery vehicles in biomedical science, are emerging as a promising tool to supplement coral nutrition. However, physiological impacts of LNPs on cnidarians, including uptake, nutritional value, and holobiont response, remain largely unexplored. Here, we delivered empty, phosphatidylcholine LNPs to both symbiotic and aposymbiotic Exaiptasia diaphana, an anemone model for corals, and analyzed the host proteomic response via mass spectrometry. LNP supplementation elicited broad proteome shifts, with notable overlap between symbiosis- and LNP-induced protein expression. Proteins involved in lipid catabolism, lipid transport, {beta}-oxidation, lysosomal function, and protein translation were significantly more abundant, consistent with enhanced lipid processing and metabolic activity. LNP supplementation, like symbiosis, suppressed both asexual reproduction and the expression of a suite of predation- and digestion-associated venom proteins and proteases, suggesting a conserved "sated" phenotype in response to lipid supply. Variations in feeding frequency with Artemia had minimal impact, indicating that LNPs can be a robust supplement irrespective of primary feeding regime. These data demonstrate that adult Exaiptasia are capable of direct uptake of LNPs, offering a tool for probing lipid metabolism, signaling and symbiotic function in cnidarians. Moreover, the ability to manipulate host physiology using defined lipid formulations holds significant potential for advancing coral aquaculture stress resilience, including reef restoration strategies.

zoology↗

bioRxiv2025

Anaerobic gut fungi Caecomyces communis, Neocallimastix frontalis and Piromyces spp. nov., have distinct effects on plant fibres during digestion.

Anaerobic gut fungi are the first colonizers of plant material that enters the digestive system of ruminants. However, it is unclear how different fungal species contribute to the ability of the rumen microbiome to convert feed to nutrients. Here we isolated three species of anaerobic fungi, including a novel Piromyces species. We investigated if these species have distinct roles in the digestion of fibrous feed components, via assessment of changes caused to plant material itself. We found Neocallimastix frontalis isolate CoB3 and Piromyces isolate SHC digested plant materials more effectively than Caecomyces communis isolate SHB. The three fungi had distinct effects on feed composition. N. frontalis CoB3 degraded hemicelluloses and cellulose to a similar extent, Piromyces spp. SHC preferentially degraded hemicellulose, while C. communis SHB preference depended on the substrate. From the panel of monosaccharides that may result from such degradative activity, all fungi consumed only glucose, suggesting involvement of mechanisms more complex than only fungal carbon source usage. Overall, this indicates that each of these fungal species have distinct roles in the degradation of plant material, and different niches in the rumen. Exploring these roles creates functional understanding of the rumen microbiome, critical for developing more sustainable agriculture.

microbiology↗