Influence of host species and seasonal interactions on bacterial community structure in fungus-growing termites: Insights into symbiotic adaptation and ecological function

Abstract

Interactions between species and environmental factors play a key role in shaping ecological and evolutionary dynamics. Understanding these interactions provides insight into how they drive species adaptation and influence the structure of bacterial communities. Fungus-growing termites essentially have a symbiotic relationship with Termitomyces fungi. Termites grow fungus gardens in their nests in structures called fungus combs, where mycelia and nodules serve as a food source for termites geminated from the digestion of plant materials by termite workers. Bacteria also play a crucial role in cellulose degradation alongside fungal symbionts. This study used 16S rRNA Illumina sequencing to explore the bacterial communities in fungus-growing termites by considering multiple factors: termite species, sample types (gut, fungus comb), vegetative types and seasons. Termite species emerged as the primary driver shaping these bacterial communities (16.7%). Additionally, interactions between termite species and season (8.7%) and between termite species and sample type (6.0%) significantly influenced the bacterial communities (p-value <0.05). Fifteen genera were identified as core microbiota, comprising over 50% of the total bacterial composition across all termite species. This dominance suggests that these core taxa play a vital role in the degradation processes that support the termite hosts. Our study indicated the impact of ecological factors, such as seasonality, in shaping the bacterial community in fungus-growing termites. Understanding these interactions is essential to uncover how bacterial communities adapt to changing environments and sustain the ecological balance within the termite ecosystem, offering broader insights into microbial ecology and host–microbe coevolution.