The production of lysine by a microbial method was studied using Brevibacterium lactofermentum (ATCC 21086) in shake flasks and a 7.5-liter fermentor. Lysine, residual glucose, cell counts, and dissolved oxygen were measured as a function of fermentation time. The effects of casamino acid, soypeptone, certain amino acids, glucose, and agitation on the rate of production and the yield were investigated. It appeared that reducing any one of the variables caused appreciable decrease in lysine production rates and yields. Plots of rate and d (log lysine)/dt were made to find the relationship between the rate of lysine production and the other factors. Plotting d (log lysine)/dt vs. lysine appears to be the most suitable method of comparing production rates. A mathematical expression was derived which appears to approximately fit the rates of lysine production.
A comparative experiment was carried out on the sixty taxonomical characteristics for the hydrocarbon-utilizing and flavin nucleotide-forming bacteria (strain S5, and new isolates S204 and S2012), and the type strain IAM 12087 (ATCC 23055) and an authentic strain IAM 12088 (ATCC 19606) of Acinetobacter calcoaceticus. Its results showed a similarity value of 85% and more among the isolates and other strains. Guanine plus cytosine content of DNA of these strains was 41 or 42%, which showed the values of Acinetobacter species. From these results, the three isolates are identified as Acinetobacter calcoaceticus according to Bergey's Manual of Determinative Bacteriology, Eighth Edition, but these isolates were named Acinetobacter anitratum (Schaub and Hauber) Brisou and Prévot 1954. The name Acinetobacter anitratum is more suitable to use as a type species name instead of A. calcoaceticus according to the International Code of Nomenclature of Bacteria. It seemed that the flavin pigmentation (flavin mononucleotide and flavin adenine dinucleotide) was one of the specificities of Acinetobacter species.
The effect of lipid A from Salmonella typhimurium and various fatty acids on the transport activities of membrane vesicles from Escherichia coli was investigated. It was found that lipid A and fatty acids severely inhibited the accumulation of succinate or serine which are coupled to the electron transport, while the transport of glucose, which was catalyzed by the phosphotransferase system, was stimulated slightly by these compounds. Lipid A and myristic acid appeared to act at the same site in the succinate transport system, since no additive effect was observed in the inhibition even at a low concentration of these compounds. Lipid A and myristic acid caused the efflux of pre-loaded 14C-succinate in the membrane vesicles.
Experiments with 14C-labeled glucose indicated that the orange-colored variety of Streptococcus bovis assimilated about 12% of consumed glucose in the synthetic medium and 6% in the peptone-yeast extract medium. These values are very much higher than those of ordinary lactic streptococci which show the values of around 0.4%. Although the yield of lactic acid did not exceed 90% of consumed glucose, this species is also a homofermenter if the assimilated glucose is taken into account. Different from ordinary lactic acid bacteria, S. bovis can grow in the medium containing ammonium salt as a sole source of nitrogen but organic nitrogen is preferable even for this species.
Localizations of malate, succinate, and alcohol dehydrogenases in the hyphae of Aspergillus oryzae were examined by a cytochemical test. These enzymes were uniformly distributed in young substrate mycelium, whereas in the conidiophore they were heavily concentrated in the apical vesicle. Malate dehydrogenases of mitochondrial and soluble fractions showed the highest activity at a growth zone where the conidiophores and aerial mycelia are formed. Isoenzyme pattern of malate dehydrogenase, as examined electrophoretically, varied characteristically depending on the hyphal age and developmental stage.