IPA COPYRIGHT: ASHP A study was made of the possible assimilation by various microorganisms of ingredients commonly used in the formulation of cosmetic products. Hydrocarbons, high molecular weight alcohols, esters and fatty acids, and silicones were studied. Microorganisms used in this study were isolated from cosmetic products. Some species of Penicillium, Candida, and Pseudomonas were noted to demonstrate strong ability to assimilate some of these ingredients. Of the materials tested, mineral oil, oleyl alcohol, stearyl alcohol, propylene glycol, isopropyl myristate, 2-hexyldecyl myristate, oleic acid, and stearic acid were found to be utilized as the sole source of carbon by most of the test organisms. Solid paraffin, multiwax, camellian, squalane, silicones, hexadecyl alcohol, polyethylene glycol, and di(2-hexyldecyl) adipate were not utilized by the organisms. The relationship between microbial assimilation and chemical structure of substrate was also determined by the use of different esters.
