ABSTRACT
Vitamin B6 was first identified as an essential nutritional component to prevent a florid dermatitis called acrodynia in rats (1). In 1938, a crystalline substance having vitamin B6 activity was isolated and identified (2, 3). This component, named pyridoxine, was required for growth of several lactic acid bacteria (4). However, Snell and coworkers found that extraordinarily large amounts of pyri-doxine were required to support growth of Lactobacillus casei or Streptococcus faecalis (5). Heat sterilization of the pyridoxinecontaining growth medium re-duced the amount of vitamin required for growth of abovementioned bacteria (5). These results indicated that heat treatment altered pyridoxine to form growth factors more potent than pyridoxine; subsequently, pyridoxal and pyridoxamine were discovered in 1944 (6).
