Researchers have identified a novel UV-blocking compound produced by heat-loving cyanobacteria from hot springs in Thailand. This biocompatible molecule, triggered by UV light and salt stress, could pave the way for eco-friendly sunscreens. The discovery highlights unique adaptations in extremophilic microbes.
In a study published in Science of The Total Environment on December 20, 2025, scientists led by Professor Hakuto Kageyama of Meijo University in Japan and Professor Rungaroon Waditee-Sirisattha of Chulalongkorn University in Thailand announced the discovery of a previously unknown compound called β-glucose-bound hydroxy mycosporine-sarcosine, or GlcHMS326. This substance is generated by the cyanobacterium Gloeocapsa species BRSZ, isolated from the Bo Khlueng hot spring in Ratchaburi Province, Thailand.
Cyanobacteria, photosynthetic bacteria that thrive in harsh environments, produce mycosporine-like amino acids (MAAs) to shield against ultraviolet radiation and neutralize reactive oxygen species. Unlike typical MAAs, GlcHMS326 features rare chemical modifications—glycosylation, hydroxylation, and methylation—enabled by a distinct biosynthetic pathway. These alterations enhance its UV absorption, stability, and antioxidant activity, making it superior in free-radical scavenging compared to common variants.
The compound's production ramps up under UV-A, UV-B, and high-salt conditions, but not heat stress, despite the microbes' thermophilic origins. Genetic analysis confirmed unique genes responsible for these modifications. "Understanding stress-responsive biosynthesis in extremophilic cyanobacteria may accelerate industrial biotechnology for natural pigment and antioxidant production," Prof. Kageyama explained.
This finding underscores the evolutionary strategies of extremophiles for survival and opens doors to sustainable applications. Prof. Waditee-Sirisattha noted, "Cyanobacteria are deemed unique among the microbial world. Our recent study underscores that extremophilic cyanobacteria are not only ecologically important but also represent a key area of research for multiple disciplines."
With rising concerns over synthetic sunscreens' side effects and environmental impact, GlcHMS326 offers promise for biocompatible UV filters in skincare and beyond. The research, available online from December 1, 2025, was funded by grants from Thailand's Science Research and Innovation Fund, Singapore's Ministry of Education, and Japan's Hibi Science Foundation.
