Studies on the growth and metabolism of the skin microbial flora

Very little has been done to examine the ecology of the human skin microflora and no systematic study of the nutrients required for the growth and metabolism of its resident members has been carried out. In this thesis, an effort has been made to provide some of such needed basic information.; In the first study, a synthetic medium (SSM) in which constituents close to that available from the skin for the growth of the common bacterial members of the skin flora was formulated. These included four parts: amino acids, various inorganic salts, certain water amino acids, various inorganic salts, certain water soluble vitamins, and some water soluble carbon and nitrogen substances. Its ability to support the growth of pure cultures of 13 numerically prominent organisms resident on human skin was tested. By elimination and addition of individual components of such a synthetic medium, components essential for the growth of individual constituents of the skin microflora were determined.; A second study was carried out to determine which skin bacteria and which substrates are involved in skin bacterial use of oxygen, since oxidation of substrates is basic to the growth of the skin bacteria. A variety of sugar, organic acid and amino acid substrates were tested using an oxygen uptake method established in our laboratory that enables rapid and accurate quantification of oxygen use.; In a third study, the degradation of glucose, lactate, urea and arginine by pure cultures of the main skin microorganisms was investigated for their possible role in the acid-base metabolism of the skin microflora that might be involved in maintenance of the skin pH. The skin bacteria in the two previous studies were examined for their catabolism of glucose and lactic acid.; The production of hydrogen peroxide during the catabolism of glucose and lactate by the skin microorganisms and their ability to catabolize hydrogen peroxide were also investigated.; Collectively, these studies have increased the knowledge of the growth needs and key metabolic processes of the main microbial members of the resident skin flora. This should help further study of the ecology and possible manipulation of the skin microflora, especially in disease states. (Abstract shortened by UMI.)...