May 14, 2025
Keio University
Toyama Prefectural University
A research group led by Lecturer Shun Saito, Professor Midori Arai, and Kaorika Okumura (a second-year master's student at the time of the research) from the Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, and Lecturer Keisuke Fukaya and Professor Daisuke Urabe from the Department of Biotechnology, Faculty of Engineering, Toyama Prefectural University, has discovered streptolactam D as a heat shock metabolite (HSM), a metabolite whose production is activated by high-temperature cultivation of actinomycetes. They also discovered a new function of this secondary metabolite: it protects actinomycetes from high-temperature stress, thereby conferring heat resistance.
For a long time, many of the secondary metabolites produced by actinomycetes were not considered essential for the growth of the bacteria themselves. It was suggested that streptolactam D, discovered as an HSM in this study, is inserted into the cell membrane of the producing bacterium, stabilizing the membrane that becomes unstable at high temperatures and thereby promoting growth at high temperatures. Further elucidation of the action mechanism of HSMs is expected to clarify the physiological significance of natural products and lead to applications in fields such as medicine and energy. The results of this research were published in the Journal of the American Chemical Society , a journal of the American Chemical Society, on April 28, 2025.
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