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Biology subjects

Schiott, M.

Publications and source records attributed to Schiott, M..

2 recordsLinked to original sources

The origin of fungi-culture in termites was associated with a shift to a mycolytic gut bacteria community

Termites forage on a range of substrates, and it has been suggested that diet shapes the composition and function of termite gut bacterial communities. Through comparative analyses of gut metagenomes in nine termite species with distinct diets, we characterise bacterial community compositions and identify biomass-degrading enzymes and the bacterial taxa that encode them. We find that fungus-growing termite guts are enriched in fungal cell wall-degrading and proteolytic enzymes, while wood-feeding termite gut communities are enriched for plant cell wall-degrading enzymes. Interestingly, wood-feeding termite gut bacteria code for abundant chitinolytic enzymes, suggesting that fungal biomass within the decaying wood likely contributes to gut bacteria or termite host nutrition. Across diets, the dominant biomass-degrading enzymes are predominantly coded for by the most abundant bacterial taxa, suggesting tight links between diet and gut community composition, with the most marked shift being the communities coding for the mycolytic capacity of the fungus-growing termite gut.

ecology

Experimental demonstration that screening can enable the environmental recruitment of a defensive microbiome

Many animals and plants recruit beneficial microbes from the environment, enhancing their defence against pathogens. However, we have only a limited understanding of the assembly mechanisms involved. A game-theoretical concept from economics, screening, potentially explains how a host selectively recruits mutualistic microbes from the environment by fomenting and biasing competition among potential symbionts in such a way that the more likely winners are antibiotic producers. The cuticular microbiomes of Acromyrmex leaf-cutting ants inspired one of the first applications of screening theory, and here we simulate this system in vitro to test screening. On agar infused with antibacterial metabolites from Acromyrmexs vertically transmitted Pseudonocardia bacteria, we show that antibiotic-producing Streptomyces bacteria exhibit higher growth rates than do non-antibiotic-producer strains and are more likely to win in direct competition. Our results demonstrate how game-theoretical concepts can provide powerful insight into host-microbiome coevolution.

evolutionary biology