How Termites Evolved to Decompose Plant Matter: Gut Bacteria and Fungus

Breaking down plant biomass for energy conversion in industrialized bioreactors remains a challenge even today. Now, scientists may be taking a cue from nature; it turns out that termite fungus farmers solve this problem and can decompose plants quickly and efficiently.

Fungus-farming termites are dominant plant decomposers in tropical Sub-Saharan Africa and Southeast Asia. In fact, in some areas they can decompose up to 90 percent of all dead plant material. They manage this feat through the multi-stage cooperation between the Termitomyces fungus and gut bacteria.

In order to better understand this interaction, the researchers analyzed plant decomposition genes in the first genome sequencing of a fungus-farming termite and its fungal crop, and bacterial gut communities.

"While we have so far focused on the fungus that feeds the termites, it is now clear that termite gut bacteria play a major role in giving the symbiosis its high efficiency," said Michael Poulsen, one of the researchers, in a news release.

"But it took a massive effort of sequencing the genome of the termite itself, its fungus and several gut metagenomics to analyze the enzymes involved in plant decomposition," said Guojie Zhang, who helped with the genome sequencing.

So what did the scientists find? It turns out that younger termites eat plant material together with Termitomyces fungalspores. They then defecate this plant-spore mix as a new layer of fungus garden. Within this garden, the fungus rapidly grows on the plant substrate until it's utilized. What's interesting is that the bacteria within the gut of the termites are crucial for this plant decomposition.

The findings reveal a bit more about how these termites manage to break down plant materials for fungal growth. These findings, in turn, can be applied to future applications.

The findings are published in the journal Proceedings of the National Academy of Sciences.