The Roles of Biotin and Carbon Dioxide in the Cultivation of Mycobacterium Tuberculosis,

Abstract

During a study of the growth of tubercle bacilli on primary isolation on oleic acid-albumin agar and on the egg medium of the American Trudeau Society (ATS), the observation was made that a number of strains, which gave growth on ATS medium, did not grow, or grew very poorly, on oleic acid-albumin agar medium (Middlebrook, Cohn, and Schaefer, 1954). In an attempt to improve this latter medium various growth factors were added, and it was found that biotin was either markedly stimulating or even absolutely required for the artificial cultivation of several strains (Middlebrook, Cohn, and Schaefer, 1954). Similarly, incubation under an atmosphere with increased COs content also stimulated the growth of these strains markedly. One strain has been observed for which biotin would not support growth at 37 C, and which was permitted to grow only by incubation under an atmosphere of air containing added C02. The purpose of this paper is to report our observations on the roles of biotin and carbon dioxide as growth factors for tubercle bacilli. MATERIALS AND METHODS The basic oleic acid-albumin agar medium used in these experiments had the following composition: KH2PO4, 1 g; Na,HPO4 (anhydrous), 2.5 g; Nas citrate 2H20, 0.1 g;

Microaerophilic Conditions Promote Growth of Mycobacterium genavense

“…Most aerobic bacteria may in fact be microaerophilic, requiring oxygen at 1,000 to 3,000 Pa, (37), but cannot tolerate oxygen at the ordinary partial pressure in air (20, (6,8,26,36,43). The investigators conducting these assays concluded that M. tuberculosis is strictly aerobic but that an atmosphere enriched with 5 to 10% CO 2 enhances growth, especially on agar media such as Middlebrook 7H10 (1).…”

The Role of the Laboratory in the Management of Tuberculosis Patients

“…The growth on the culture plates is graded and reported according to the scheme given in Table 5. 23 The importance of CO 2 is greater with agar-based media, although even with egg-based media it facilitates greater and quicker growth. 24 More recently special media modifications that do not require the digestion and decontamination procedures have been developed in both England 25 and Denver.…”

The mechanism of carbon dioxide fixation by the acid-fast organism, Mycobacterium phlei

“…The stimulating effect of increasing carbon dioxide tension and reducing the requirement for biotin by increas ing carbon dioxide tension (Broquist and Snell, 1951;Schaefer et al, 1955) could be due, at least partly, to a biotin-sparing effect.…”

“…It is interesting that a compound acts both ways, namely as an inhibitor and as a growth factor, under different conditions. The presence of oleic acid increased the requirement for biotin or carbon dioxide in the case of growth of Lactobacillus arabinosus (Broquist and Snell, 1951) and of Mycobacterium (Schaefer et al, 1955). The mode of action is not known.…”

“…The necessity of carbon dioxide for the growth of acidfast bacteria has been known for quite some time (Wherry and Ervin, 1918;Rockwell and Highberger, 1926;Masur, 1926;Davies, 1940;Schaefer et al, 1955). The role of carbon dioxide, however, is not well understood.…”