Effect of metavanadate ion on the growth in vitro of Mycobacterium tuberculosis.

Little information is available on the effects of vanadium ion on microbiological systems. At least three investigators have reported that salts of vanadium may be stimulatory to the growth in vitro of species of mycobacteria when these organisms are grown in the absence of iron. Frouin (1912) found that growth of the bovine tubercle bacillus was aided by addition of the sodium salt of vanadium to his synthetic medium which contained no added iron. Using a modification of Long's synthetic medium, Boissevain (1926) reported that vanadium chloride effectively replaced ferric ion in growth of the human "Test" strain. Turian (1951) noted that NaVO3 increased growth of Mycobacterium phlei by 25 per cent. Previous investigations have indicated a role for this metal in: (a) replacing molybdenum in microbial nitrogen fixation pathways (Bortels, 1933; Burk, 1934); (b) as a molybdenumindependent, essential growth factor for green alga (Arnon and Wessel, 1953); and (c) in effecting alterations in mammalian lipid oxidation (Bernheim and Bernheim, 1939) and synthesis (Curran, 1954; Curran and Costello, 1956; Mountain et al., 1956; Azarnoff and Curran, 1957). It seemed that the complex functions of vanadium might best be studied in a species of bacteria which produced enzymes both for the reduction of inorganic nitrogen and for the synthesis of relatively large amounts of lipid. Because of the reported stimulation of species