[S1-5] Diversity of secondary metabolism using nitrogen oxides in actinobacteria
Actinobacteria are Gram-positive bacteria with high GC content and are known to produce a variety of secondary metabolites. These secondary metabolites have long been recognized as important pharmaceutical resources because of their diverse structures and biological activities. Therefore, their biosynthetic mechanisms have long been a subject of interest. Nitrogen oxides are important intermediates in the nitrogen cycle in soil and are involved in microbial energy acquisition. Recent studies have revealed that nitrogen oxides are used not only for energy acquisition but also for secondary metabolism and that many actinobacteria use nitrogen oxides (NO and NO2-) for the production of secondary metabolites. We discovered a unique metabolic pathway that produces nitrite (NO2-) from cremeomycin, a diazo-containing secondary metabolite, biosynthesis. This nitrite is directly used for the synthesis of the diazo group of cremeomycin. This pathway is conserved in various actinobacteria, suggesting that it is used for the biosynthesis of a variety of secondary metabolites. In addition to nitrite, nitric oxide (NO) is also used for the production of secondary metabolites in actinobacteria. In this presentation, we will introduce recent examples of secondary metabolism in actinobacteria using these nitrogen oxides and discuss their role in the microbial community.