Abstract Actinomycetes are ubiquitous in the environment and play crucial roles in soil and natural ecosystems. They are well known for producing a wide variety of secondary metabolites—chemical compounds that include antibiotics, pigments, and other pharmacologically active compounds—which have made significant contributions to medicine and industry. Secondary metabolites have traditionally been regarded as nonessential for microbial growth and survival. However, recent studies have revealed that these compounds play significant roles in the regulation of growth, differentiation, biological interactions, and stress responses in actinomycetes. For example, our research showed that actinomycetes produce a group of compounds known as heat shock metabolites when exposed to elevated temperatures. These metabolites contribute to growth under high-temperature conditions. Such findings indicate that secondary metabolites not only affect other organisms or the environment but also play key roles in the self-regulation and adaptive strategies of the producing microbes. This review summarizes current knowledge regarding how secondary metabolites produced by actinomycetes are functionally integrated into the organism's physiological processes, with the aim of providing insights useful to a broad scientific readership.
Shun Saito (Fri,) studied this question.