Effects of some fatty acids on the development of staphylococcus auereus

An attempt has been made to determine whether or not some short and long chain fatty acids exert anti- microbial influences on the development of S. aureus in vitro. Solutions of fatty acids, ranging from 1.0 to 1.0 x 10⁻⁴ M, were adjusted to pH 7.2 with 1 N NaOH and incorporated into media as sources of carbon. Effects exerted by these acids on staphylococcal development were determined using a streak plate and spectrophotometric technique. Results showed that formic, acetic, propionic, butyric, capric, lauric and myristic acids all inhibited the growth of the organism. The degree of inhibition was related to the concentration of the acid employed as well as to its molecular structure (i.e. chain length and degree of saturation). However, an increase in growth of the bacteria when grown in the presence of lactic acid showed that the organism was capable of utilizing this substrate as a source of carbon. Possible mechanisms for the effects of these acids on S. aureus development were also discussed.