Studies on the carbohydrate metabolism of skin

Abstract

BACTERIAL REDUCTION OF QUINIC ACID 285 shikimic acid or whether the reduction of the two compounds follows separate routes. The results show, however, that quinic acid and shikimic acid are interconvertible. In the scheme studied by Davis (1955) with Escherichia colti mutants it appears that quinic acid is not in the direct sequence leading from carbohydrate through shikimic acid to the aromatic metabolites. In this scheme the precursors of shikimic acid are 5-dehydroquinic acid and 5-dehydroshikimic acid. In the present tests it has not been possible to demonstrate the formation of either of the latter two compounds. The possible participation of quinic acid in a sequence leading to aromatization is, however, not excluded since in the wild-type Aerobacter aerogenes quinic acid is a precursor of 5-dehydroquinic acid. In the lactic acid bacterium investigated there is as yet no evidence to suggest the role of shikimic acid as a precursor of aromatic amino acids. SUMMARY 1. Growing and resting cells of an organism occurring in cider, Lactobacillu8 pastorianus var. quinicu8, are capable of converting quinic and shikimic acids into dihydroshikimic acid.