The comparative activities of pantethine, pantothenic acid, and coenzyme A for various microorganisms.

Several fastidious lactic acid bacteria require a new growth factor, originally termed the Lactobacillus bulgartcu8 factor (LBF), for growth on synthetic media (Williams, Hoff-Jorgensen, and Snell, 1949; Kitay and Snell, 1950). Highly purified concentrates of this factor contained bound pantothenic acid, a finding that led to the discovery that LBF was apparently identical with the fragment of coenzyme A obtained by treatment with intestinal phosphatase (Brown, Craig, and Snell, 1950). Amounts of pantothenic acid much higher than those usually added to synthetic media were found to promote growth in place of LBF (Brown et al., 1950; McRorie et al., 1950). More recently, synthesis of a conjugate of pantothenic acid that has LBF activity was achieved (Snell et al., 1950). This conjugate exists in a sulfhydril and disulfide form, termed, respectively, pantetheine and pantethine. Preliminary comparisons of chemical and biological properties indicated that pantethine was identical with LBF prepared from natural sources.2 Since both products have been obtained only in noncrystalline form, further comparisons of the natural and synthetic product appeared of value, as well as further delineation of their activity for various microorganisms. Such comparisons of biological activities for 22 different organisms are reported below. The activities of calcium pantothenate and of a coenzyme A concentrate were also determined for the same organisms.