Fungal Bioprocessing of Lignocellulosic Biomass for Ruminant Nutrition

Ruminant livestock systems often rely on fibrous agricultural residues rich in cellulose and hemicellulose but bound by a recalcitrant lignin matrix. Fungal bioprocessing employs ligninolytic fungi—predominantly white-rot species—to selectively degrade lignin and partially solubilise hemicellulose, enhancing access to fermentable carbohydrates. Through solid-state fermentation under controlled moisture and aeration, these fungi secrete an array of oxidative and hydrolytic enzymes, including peroxidases and laccases, which disrupt lignin structure without excessive cellulose loss. The treated substrates exhibit higher crude protein content, improved neutral detergent fibre digestibility and elevated in vitro gas production, indicative of enhanced ruminal fermentation. Practical considerations span strain selection, substrate pretreatment, inoculum density and incubation time, all of which govern delignification efficiency and nutrient preservation. Scaled from laboratory to on-farm contexts, fungal pretreatment of straw, corn stover and other residues offers a sustainable route to valorise crop by-products, reduce feed costs and mitigate environmental impacts of waste accumulation.

Research from Nature Portfolio

Recent studies have adapted white-rot fungal treatment of straw and rice straw under farm-relevant conditions, demonstrating up to 50% improvement in indicators of ruminal degradability after 4–6 weeks of solid-state fermentation. Trials with Pleurotus ostreatus, Ceriporiopsis subvermispora and Volvariella volvacea revealed that simple physical pretreatments—such as remoistening or autoclaving—can further boost gas production and enzymatically soluble organic matter. Separate work comparing axenic and coculture fermentations of rice straw showed that monocultures of P. ostreatus yielded the greatest lignin reduction and in vitro dry matter digestibility, while coculture systems exhibited antagonistic interactions that limited expected synergistic gains. These findings underscore the importance of fungal species choice and interactions in optimising feed quality.

Fungal Bioprocessing of Lignocellulosic Biomass for Ruminant Nutrition publication trend

The graph below shows the total number of articles in fungal bioprocessing of lignocellulosic biomass for ruminant nutrition across all publications each year (not limited to Nature Index journals).

Technical terms

Lignocellulosic biomass: Plant material composed of cellulose, hemicellulose and lignin forming a rigid matrix.

White-rot fungi: A group of basidiomycetes capable of degrading lignin via extracellular oxidative enzymes.

Delignification: The selective removal or breakdown of lignin to expose carbohydrate polymers.

Solid-state fermentation: Cultivation of microorganisms on moist solid substrates without free liquid.

In vitro gas production (IVGP): A laboratory measure of fermentability based on gas evolved during simulated rumen digestion.

Crude protein (CP): An estimate of protein content calculated from total nitrogen in a feed sample.

References

1. In vitro ruminal degradability of wheat straw cultivated with white-rot fungi adapted to mushroom farming conditions. Scientific Reports (2023).
2. Effect of ligninolytic axenic and coculture white-rot fungi on rice straw chemical composition and in vitro fermentation characteristics. Scientific Reports (2022).
3. Screening of white‐rot fungi for bioprocessing of wheat straw into ruminant feed. Journal of Applied Microbiology (2018).
4. Chemical changes and increased degradability of wheat straw and oak wood chips treated with the white rot fungi Ceriporiopsis subvermispora and Lentinula edodes. Biomass and Bioenergy (2017).
5. Biological treatment of crop residues for ruminant feeding: A review. African Journal of Biotechnology (2013).
6. The effect of particle size and amount of inoculum on fungal treatment of wheat straw and wood chips. Journal of Animal Science and Biotechnology (2016).
7. Enhancement of the nutritional value of fermented corn stover as ruminant feed using the fungi Pleurotus spp.. Scientific Reports (2021).