Studies in the Actinomycetaceae. The nutrition of the Streptomycetes

Thirty six cultures of streptomycetes taken from a collection gathered from various sources were used in this study, and an attempt made to identify them using well known bacteriological techniques. A. description of each organism is given in Appendix I and details of the media used in Appendix II. The nutrition of the organisms was examined under conditions designed to eliminate unwanted utilisable substances. All glassware was acid washed; chemicals were the finest quality available. The ability of each organism to assimilate (1) each of 30 carbon substances using ammonium sulphate as nitrogen source, and (2) each of 25 nitrogen substances using sodium pyruvate as carbon source, was investigated. The requirements of 10 of the organisms for 8 growth factors was also studied. All the nutritional experiments were aerated by shaking. The production of acid from carbohydrates was explored using several techniques. From these experiments it was concluded that:- 1). Twenty-seven of the cultures were strains of Streptomyces albus species-group; the remaining organisms each belonged to a different species. 2). Simple sugars and some organic acids were well utilised. Alcohols, with the exceptions of glycerol and mannitol, were not well assimilated, nor were simple fatty acids except acetate. 3). Ammonium and nitrate were good inorganic nitrogen sources. Nitrite supported the growth of many strains providing that the optimum concentration was used, together with a carbon source which was available under those conditions. Amino acids, except cystine, methionine, valine and tryptophane supported excellent growth. Urea, uric acid and xanthine were also excellent nitrogen sources for these organisms. 4). None of the organisms examined required any of the growth factors investigated. 5). The carbon assimilation of the Streptomyces albus strains fell into 3 patterns, suggesting that this species-group contains at least 3 nutritional types. The nitrogen assimilation pattern could not be used to differentiate between organisms. 6). No satisfactory method of investigating acid production by streptomycetes was found, and the results obtained were equivocal. A survey of the relevant literature and a bibliography are included

Synthesis of the major unsaturated fatty acids of an estuarine Flexibacterium

Fatty acid composition of the Flexibacter strains Inp2 and Inp3 were found to be influenced by the presence of cAMP. Whilst cAMP inhibited the synthesis of linoleic and linolenic acid in Inp2, cerulenin inhibited the synthesis of Cl6:l. This suggests that lnp strains possess both the aerobic and anaerobic pathway for synthesis of unsaturated fatty acids (UFAs)