Food Storage by the Savanna Termite Cornitermes cumulans (Syntermitinae): a Strategy to Improve Hemicellulose Digestibility?

Abstract

It has been suggested that food storage inside the nest may offer termites with a nutritional provision during low resource availability. Additionally, feces employed as construction material provide an excellent environment for colonization by microorganisms and, together with the storage of plant material inside the nest, could thus provide some advantage to the termites in terms of lignocellulose decomposition. Here, we conducted for the first time a comprehensive study of the microbial communities associated to a termite exhibiting food storage behavior using Illumina sequencing of the 16S and (ITS2) regions of rRNA genes, together with enzymatic assays and data collected in the field. Cornitermes cumulans (Syntermitinae) stored grass litter in nodules made from feces and saliva located in the nest core. The amount of nodules increased with nest size and isolation, and interestingly, the soluble fraction of extracts from nodules showed a higher activity against hemicellulosic substrates compared to termite guts. Actinobacteria and Sordariales dominated microbial communities of food nodules and nest walls, whereas Spirochetes and Pleosporales dominated gut samples of C. cumulans. Within Syntermitinae, however, gut bacterial assemblages were dissimilar. On the other hand, there is a remarkable convergence of the bacterial community structure of Termitidae nests. Our results suggest that the role of nodules could be related to food storage; however, the higher xylanolytic activity in the nodules and their associated microbiota could also provide C. cumulans with an external source of predigested polysaccharides, which might be advantageous in comparison with litter-feeding termites that do not display food storage behavior.

Targeted biomass degradation by the higher termite gut system - integrative omics applied to host and its gut microbiome

“…9). This indicates constant complementation of diet with nitrogen rich chitin, originating from either necrophagy and/or cannibalism, or fungi-colonised food stored in the nest, as previously proposed for other higher termite species 29 .…”

Microbial Communities of the Gut and Nest of the Humus- and Litter-Feeding Termite Procornitermes araujoi (Syntermitinae)

“…For example, gut symbiont composition in wood-feeding species consists mainly on Fibrobacteres and Spirochetes which are known to have a strong cellulolytic activity [28,31]. Conversely, the microbiota of grass/litter-feeding species consisted mainly on Firmicutes [27,32,35,44,55], thus corroborating that the type of diet is related to the community structure of their bacterial gut symbionts.…”

“…33269). Data regarding microbial gut microbiome of C. cumulans and S. euamignathus were obtained from Menezes et al [35]. All applicable international, national, and/or institutional guidelines for the care and use of animals were followed.…”

“…Basal lineages of termites depend on flagellate protists and prokaryotes for lignocellulose digestion [24]. In contrast, the evolutionary success of Termitidae is attributed to the loss of cellulolytic flagellates and acquisition of a specialized bacterial flora, together with a highly dietary diversification and feeding strategies [5,7,22,35]. Comparative studies have revealed a diet-related compositional convergence of termite gut microbiota from the same feeding guild [16,51].…”

“…The subfamily Syntermitinae is a monophyletic group of Termitidae comprising approximately one hundred species that range in their feeding habits from wood and litter-feeding to humus-feeding species [52]. Although basic aspects of the feeding ecology of the Syntermitinae remain poorly studied, the microbial communities of these termites can be very complex and diverse [35,55]. Procornitermes araujoi (Emerson 1952) is a harvester Syntermitinae in savannas of central and southeastern Brazil [8,9,13,23].…”