Abstract
A novel enzymatic method for the production of L-carnitine (L-4-trimethylamino-3-hydroxybutyric acid) has been developed.
Microorganisms that asymmetrically produce L-carnitine from trans-crotonbetane(trans-4-trimethylamino-2-butenoic acid), which was easily supplied through the chemical dehydration of DL-carnitine with an acid, were screened from stock cultures in our laboratory. Of the 686 strains of microorganisms examined, i.e., 416 bacteria, 37 actinomycetes and 233 yeasts, strains belonging to the genera, Proteus and Escherichia, were found to be efficient producers of L-carnitine from trans-crotonbetaine. Through the screening, Proteus mirabilis AJ-2772 and AJ-12137, with potent abilities, were selected as representative strains. The trans-crotonbetaine-hydrating enzyme was inducibly and intracellularly produced on either the addition of trans-crotonbetainQ or L-carnitine to the medium under partially anaerobic conditions.
With intact cells of P. mirabilis AJ-2772, 40 g/l of L-carnitine chloride was produced from 62.5g/l of trans-crotonbetaine.
