α-HYDROXYGLUTARATE: PRODUCT OF AN ENZYMATIC BETACONDENSATION BETWEEN GLYOXYLATE AND PROPIONYL-COENZYME A

or suspensions of individual or mixed fractions in a phosphate buffer (pH 6.8) containing 0.9% sodium chloride, at room temperature for 1 to 2 weeks. Subcultures were made on blood agar, and then again in solutions of mycobacterial fractions. Starting with the third series of subcultures, the cultures were centrifuged at 17,000 X g for 10 min. Collected supernatants were recentrifuged at 27,000 X g for 10 min, then concentrated to one-half to one-third volume at room temperature by the use of a fan. Filtrates were serially diluted and tested against an equal volume of individual fractions of mycobacteria diluted 1:20,000 or 1:50,000 in a complementfixation test, as described by Kwapinski and Snyder (The Immunology of Rheumatism, Appleton-Century-Crofts, New York, 1961). Adequate controls of fraction solutions and filtrates at double concentrations were set up simultaneously. Some fractions were also tested against the culture filtrates in the Ouchterlony test. Results based on 15 series of tests showed that filtrates of Candida and Rhodotorula grown in the presence of nucleoprotein fractions, and particularly in the solutions of combined nucleoprotein and carbohydrate or nucleoprotein and phospholipid fractions, gave regularly a strong complement fixation when tested against nucleoprotein and polysaccharide, but not against phospholipid, fractions. In the diffusion precipitation test, only nucleoprotein fractions reacted, and less regularly, with the culture filtrates. This preliminary work is being followed by larger series of similar tests and by investigations to elucidate the nature and mechanism of these phenomena, which have characteristics similar to those of a true serological reaction.