Regulation of bile acid synthesis in man is incompletely understood, in part because of difficulty in making measurements over short time periods when the enterohepatic circulation is intact. We investigated the possibility of a diurnal rhythm of bile acid synthesis in three human subjects given [26-14C]cholesterol. When this isotope of cholesterol, which is randomly labeled in the 26 and 27 po...

Propionic acid (10(-3)m) increases ethylene production by about 30 to 60% in tissue from green and half-ripe tomatoes (Lycopersicon esculentum Mill. var. Homestead) but does not increase ethylene production in tissue from ripe fruit. Stimulation is not due to the conversion of propionic acid to ethylene but appears to be secondary in nature and to operate on the endogenous ethylene-forming syst...

Propionic acid was one of the early products observed as resulting from bacterial action. Kearly 70 years ago (1854) Strecker (I) reported it as resulting from a fermentation of mannitol which he had studied, while Pasteur (2) also found propionic acid as one of the products formed in the fermentation of calcium tartrate. As these early observations were not made upon pure cultures, it is impos...

CZostridium propionicum evidently possesses a mechanism for the conversion of lactate to propionate different from that found in the previously studied propionic acid producing bacteria. Reactions common to certain propionibacteria and VeiZZoneZZa gazogenes which could not be demonstrated with Cl. propionicum include : ( a ) the decarboxylation of succinic acid ; (b) the fermentation of malate ...

The major pathway of histidine metabolism in animals and bacteria other than incorporation into protein involves first deamination to urocanic acid, then the anaerobic addition of water to form an intermediate generally considered to be 4(5)imidazolone-5(4)-propionic acid (1, 2). Finally, the ring is split enzymatically to ~formiminoglutamic acid (3) which is converted to free cglutamic acid by...

BACKGROUND Propionic acid is used primarily as a food preservative with smaller applications as a chemical building block for the production of many products including fabrics, cosmetics, drugs, and plastics. Biological production using propionibacteria would be competitive against chemical production through hydrocarboxylation of ethylene if native producers could be engineered to reach near-t...

We investigated whether 3-(trihydroxygermyl) propionic acid increases the formation of cornified cell envelopes and the level of ceramide in cultured epidermal keratinocytes and in a three-dimensional human epidermis model. The activity and mRNA expression of transglutaminase were increased when 3-(trihydroxygermyl) propionic acid was added to the cell cultures. The formation of cornified cell ...

Propionic acid (propionate) is a commercially valuable carboxylic acid produced through microbial fermentation. Propionic acid is mainly used in the food industry but has recently found applications in the cosmetic, plastics and pharmaceutical industries. Propionate can be produced via various metabolic pathways, which can be classified into three major groups: fermentative pathways, biosynthet...