Characterization of the initial degradation mechanism involved in <i>C</i> -glycosylated isoflavone puerarin in soil microorganism

Plants, fungi, bacteria, and insects synthesize various kinds of unique compounds. Those synthesized compounds are generally degraded by microorganisms; otherwise, they would accumulate on the surface of the Earth. However, in many cases, their fate in the natural environment remains poorly understood. In this study, we isolated a bacterium from soil by the enrichment culture method and identified it as <i>Paenarthrobacter</i> sp. No. 37. This strain was able to grow in the medium containing puerarin as the sole carbon source. It revealed that strain No. 37 can utilize puerarin as a source of carbon and energy. Furthermore, a puerarin degradation activity was induced upon the addition of puerarin to the culture medium. Thus, we successfully identified a bacterium that physiologically catabolizes puerarin and potentially other <i>C</i>-glycosylated compounds. By uncovering <i>C</i>-glycoside metabolism in natural environments, our findings shed light on the part of microbial contribution to the degradation and regeneration of plant-derived natural compounds in biogeochemical cycles.