Biotin is a growth factor that plays an important role in numerous reactions that are critical to microorganisms, plants, and animals. Biotin has a strong affinity for the protein avidin, a trait that has been utilized for many assay reporter applications. KAPA is a key intermediate in the biotin biosynthetic pathway.[1]
Reference:
[1]. Izumi, Y., and Yamada, H. Microbial production of biotin. Biotechnology of vitamins, pigments and growth factors 231-256 (1989).