There is growing interest in discovering yeast with novel functional traits relevant for industrial applications. Insects are increasingly becoming an attractive source of novel yeasts. Sugar-seeking insects, together with their natural niches such as wild fruits and their nectary flowers, have been extensively explored as habitats supporting novel diverse yeast communities. However, insects occupying low-sugar niches remain understudied, particularly fungus-growing termites that rely on lignocellulosic substrates as their primary carbon source. This study examined the diversity and functional potential of gut-associated yeasts from mound-building termite Macrotermes michaelseni whose large conspicuous mounds are major landmarks of southeastern Botswana region and the Okavango Delta. Fungus-growing termites were collected from multiple locations across the region and yeasts were isolated, identified and evaluated for their ability to assimilate diverse, industrially relevant carbon sources. Selected isolates were further analysed for lipid accumulation and potential antifungal activity as key traits linked to fungal mutualism and host protection. A total of 48 yeast and yeast-like isolates were recovered from 17 of the 29 termite specimens, each originating from a distinct mound distributed along nearly 900 km of ecological gradient across Botswana. The most represented genus was Cystobasidium (56%), a red yeast formerly classified as Rhodotorula, followed by Aureobasidium (19%), a black yeast-like fungus and then Schwanniomyces sp. (13%). Although taxonomically diverse, the yeast isolates displayed statistically indistinguishable carbon assimilation profiles across all tested sugars, suggesting functional convergence within the gut of Macrotermes michaelseni and thus underscoring their potential ecological role in carbon metabolism, including lignocellulosic sugars such as xylose and arabinose. Selected isolates of Cystobasidium, Rhodotorula and Schwanniomyces genera exhibited lipidome profiles with diverse fatty acid methyl esters (FAMEs) with potential functional relevance in this association. These findings suggest that termite-associated yeasts possess metabolic traits compatible with the lignocellulosic termite gut environment and may contribute unique functional benefits to the host, revealing fungus-growing termites as promising reservoirs of yeasts with potential industrial applications.
Makopa et al. (Thu,) studied this question.