Assimilation of berberine and chelidoxanthine by bacteria

Summary Several species of bacteria are able to assimilate the alkaloid berberine while growing in extracts ofBerberis vulgaris, Chelidonium majus, andMahonia aquifolium. They can also assimilate the alkaloid in nutrient media containing berberine hydrochloride in concentrations up to and including 2.0 per cent, but only if provided with suitable sources of carbon and nitrogen. Some bacteria, especially Gram-positive species, were found to be sensitive to relatively low concentrations of the alkaloid. The alkaloid appeared to be assimilated during the early stages of growth, and to be held in the protoplasm, for surface growth on agars and the washed cells had the bright yellow fluorescence of berberine, in ultra violet light. In mineral salts media with glucose and with amino acids as sources of nitrogen the intake of the alkaloid appeared to be stimulated by aspartic acid, glutamic acid, cysteine, methionine and taurine. Bacterial cells washed from colonies on agar containing the alkaloid served as a source of nitrogen to other bacteria, which extracted and assimilated the berberine from the washed cells.Contribution from the Faculty of Agriculture, Macdonald College, Que., Canada, Journal Series No. 403.The work formed part of that done by the junior author in partial fulfillment of the requirements for the Ph. D. degree of McGill University.