Nitrogen fixation in different termite lineages and diets.

This article focuses on comparing nitrogen fixation rates and nitrogenase gene expression between two termite families, Kalotermitidae (drywood termites) and Rhinotermitidae (subterranean termites), to understand their nitrogen acquisition strategies. The study found that drywood termites, which are confined to a single piece of wood and lack access to soil, exhibit significantly higher nitrogenase expression, relying heavily on intrinsic atmospheric nitrogen fixation for colony growth. In contrast, subterranean termites show nitrogenase activity similar to ambient soil levels, indicating they supplement their nitrogen needs by ingesting nitrogen-rich soil organic matter. These findings suggest that access to soil allows subterranean termites to reduce dependence on metabolically costly nitrogen fixation, influencing their colony development and ecological diversification.