The Heat of Change: Impacts of Rising Temperature on Excreted Metabolites and Antibacterial Activity in Nests of Anoplotermes pacificus

• Grant number: 25/24059-1
• Support Opportunities: Scholarships in Brazil - Program to Stimulate Scientific Vocations
• Start date: June 11, 2026
• End date: July 30, 2026
• Field of knowledge: Health Sciences - Pharmacy - Pharmacognosy
• Principal Investigator: Denise Brentan da Silva
• Grantee: Eduardo Santos Barbosa Ferreira
• Host Institution: CENTRO CIENCIAS BIOLOGICAS SAUDE/UFMS

Abstract

Termites (Blattodea: Isoptera) are eusocial insects that play a fundamental ecological role by actively contributing to the carbon cycle through the decomposition of lignocellulose in plant substrates. The digestion of this material is a complex process mediated by symbionts present in the termite gut microbiota, which are also associated with the nests, as fecal material mixed with saliva is used in mound construction. Consequently, a large portion of the microorganisms found in termite nests originates from the gut, with actinobacteria standing out for their ability to produce bioactive secondary metabolites with antimicrobial properties. Studies have shown that these bacteria constitute one of the dominant microbial groups in the inner walls of termite nests, and that the environmental conditions of these structures favor their colonization and growth compared to those in the host intestine. Termites depend on these symbiotic bacteria associated with the nest as an important defensive mechanism, since the antimicrobial compounds produced contribute to protection against pathogens and to the maintenance of the colony's social immunity. However, little is known about how climate change-especially the increase in temperature-may affect the production of these metabolites and, consequently, the effectiveness of the nests' antibacterial defense. As the global average temperature rises, physiological and ecological alterations may impact the symbiotic microbial communities, modifying their composition and metabolic activity. In this context, the present project aims to evaluate the impact of rising temperature on the antibacterial activity and the profile of excreted metabolites in nests of the termite Anoplotermes pacificus (Termitidae: Apicotermitinae). This species was selected because its nest size allows for experimental manipulation under controlled laboratory conditions. Samples of internal nest material will be subjected to different temperature (25 °C, 28 °C, and 40 °C) and relative humidity (50% and 70%) conditions in a bioclimatic chamber. The extracts obtained using methanol and water (7:3, v/v) will be concentrated, lyophilized, and analyzed by high-performance liquid chromatography coupled with diode array detection and mass spectrometry (HPLC-DAD-MS). The metabolites will be annotated and organized into molecular networks using the GNPS platform, allowing visualization of chemical variations associated with the experimental conditions. The antibacterial activity of the extracts will be evaluated against clinically relevant pathogenic bacteria, including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus epidermidis. Additionally, antibacterial photodynamic inactivation will be investigated as a complementary method to explore the biotechnological potential of the metabolites produced. The expected results include the characterization of the impact of temperature increase on the metabolic composition and antibacterial activity of termite nests, contributing to a better understanding of how climate change may influence the symbiosis between termites and their associated microorganisms.