Substitution of known compounds for ascitic fluid in the cultivation of Borrelia vincentii

DEPENDENCY OF TREPONEMA MICRODENTIUM ON OTHER ORAL ORGANISMS FOR ISOBUTYRATE, POLYAMINES, AND A CONTROLLED OXIDATION-REDUCTION POTENTIAL

Socransky, S. S. (Forsyth Dental Center, Boston, Mass.), W. J. Loesche, C. Hubersak, and J. B. Macdonald. Dependency of Treponema microdentium on other oral organisms for isobutyrate, polyamines, and a controlled oxidation-reduction potential. J. Bacteriol. 88:200-209. 1964.-Strains of Treponema microdentium can be cultivated on a variety of autoclaved commercially available media in the presence of other oral organisms. Organisms supporting growth in these circumstances include a facultative diphtheroid accompanied by either a strain of Fusobacterium or a motile gram-negative anaerobic rod. Culture filtrates and lysates of these "supporting organisms" failed to substitute for growing organisms. Measurement of the oxidation-reduction potential of the test system demonstrated that the spirochetes grew in a narrow range of Eh (optimum, -190 mv). The supporting organisms could be replaced by their filtrates when the Eh of the medium was poised in this range by a combination of reducing agents. Both filtrates contained a heat-labile factor required by the spirochete, which could be replaced by 5 mug/ml of cocarboxylase. Isobutyric acid, which could be detected in the fusiform filtrate, and putrescine which could be detected in the diphtheroid filtrate, replaced the spirochete's remaining filtrate requirement. Maximal growth occurred when any of the following were incorporated into the medium: 2 mug/ml of sodium isobutyrate; 250 mug/ml of putrescine dihydrochloride; 200 mug/ml of spermidine phosphosphate, or 150 mug/ml of spermine tetrahydrochloride.

Nutritional requirements of anaerobic spirochetes. I. Demonstration of isobutyrate and bicarbonate as growth factors for a strain of Treponema microdentium

Hardy, Paul H., Jr. (The Johns Hopkins University School of Medicine, Baltimore, Md.), and Carole O. Munro. Nutritional requirements of anaerobic spirochetes. I. Demonstration of isobutyrate and bicarbonate as growth factors for a strain of Treponema microdentium. J. Bacteriol. 91:27-32. 1966.-The previously reported ability of a microaerophilic diphtheroid to support the growth of some oral spirochetes resides in the acid-distillable fraction of the culture fluid. This fraction can be replaced by isobutyrate and, to a lesser extent, by 2-methylbutyrate. When media are supplemented with isobutyrate alone, there is a prolonged lag phase before spirochetal growth commences, but when sodium bicarbonate is also added the lag phase is shortened, and both the growth rate and the total yield are increased. Serum, in low concentration, also acts as a growth stimulant, but it is inhibitory when present at higher concentrations.