Actinomyces (Streptomyces) roseoflavus var. roseofungini which yields secondary nocardioform colonies when grown on synthetic medium with D- fructose as sole carbon and energy source ("fructose effect") was employed as test organism in screening for conditions and compounds which enhance or retard the fructose effect. The results of alterations in cultivation conditions point to the importance of fructose being metabolized for its effect to be observed. The effective individual compounds tested were tentatively grouped as follows: (1) Strongly inhibitory in high concentrations for the growth of actinomycete while retarding emergence of secondary colonies against the background of weak growth in moderate or low concentrations (most antibiotics and some enzyme inhibitors, phenol, indole, anthranillic acid, indolyl-acetic acid, sodium hydrosulphite, iron salts). (2) Non-inhibitory for growth (occasional stimulation noted), retarding emergence of secondary colonies, a) Active in low concentrations (mannitol, tyrosine, shikimate, oxalate, alanine, valine, norvaline, leucine). b) Active in high concentrations (glucose, galactose, glycerol, ascorbate, citrate, lactate, several amino acids). (3) Non-inhibitory for growth with slight tendency to enhance emergence of secondary colonies (fumarate, malate, succinate, phenylalanine, sodium chloride). Compounds of group 3 neither individually nor in combinations were able to substitute fructose in its capacity to elicit secondary growth. Some treatments (increase in incubation temperature, addition of methionine) tended to increase the relative number of secondary colonies of diminished size. The results are discussed in relation to the possibility that emergence of secondary colonies is due to some "abnormalities" in fructose metabolism, leading to production of metabolites which induce and/or select particular type of mutants. Among effective additives some (mannitol) probably affect the fructose metabolism itself, while others "cure" the lesions due to its "peculiarity" or improve the efficiency of fructose utilization.
Theoretical study was made on the transient behavior of a single-vessel continuous fermentation in which the growth of a microorganism is inhibited by its product. When the product formation was negatively growth-associated, occurrence of diverging as well as damped oscillations was shown with the analog computer. No oscillation could be observed, on the other hand, when the product formation was either completely growth-associated, completely non-growth associated, or partially growth-associated. The present model for a product-inhibited chemostat covers the Stepanova-Romanovskii model as one of its special cases, while it is in parallel with the Ramkrishna- Fredrickson-Tsuchiya model that deals with a chemostat in which one of its products has a cell-killing effect on the microorganism.
1) Lipopolysaccharide with pyocin R receptor activity was isolated from Pseudomonas aeruginosa P14 by the phenol method. Lipopolysaccharide was dissociated and fractionated into amino-sugar-rich fraction and lipopolysaccharide subunits by Sephadex G-100 gel filtration after heat treatment in the presence of sodium deoxycholate. 2) The lipopolysaccharide subunits (mol. wt. 12, 000-16, 000) had no receptor activity in the presence of sodium deoxycholate, but they were reassociated in the absence of sodium deoxycholate and the activity was recovered. Therefore, the subunits may be regarded as the chemical entity of the receptor activity. 3) Chemical analysis of the reassociated lipopolysaccharide and the carbohydrate fragment (mol. wt. 1, 300-1, 500) after acid treatment for the elimination of "lipid A" was carried out. The former contained glucose, rhamnose, heptose, glucosamine, galactosamine, quinovosamine, fucosamine, and a 2-keto-3-deoxy-sugar acid. The latter contained only glucose, rhamnose, heptose, galactosamine, 2-keto-3-deoxy-sugar acid, and phosphate.
Cellular fatty acid spectra of Sporolactobacillus species and some other Bacillus-Lactobacillus intermediates were comparatively examined with special reference to their taxonomy. Bacillus coagulans, 4 strains of Sporolactobacillus, and other spore-forming lactic acid bacteria were found to have "iso- anteiso-type" fatty acid spectra similar to those previously reported for most species of Bacillus. Iso- or anteiso- branched odd-numbered carbon acids were predominant in the fatty acids of these organisms. Lactobacillus yamanashiensis, a motile, diaminopimelic acid-containing, but non-spore-forming lactic acid bacterium was found, in contrast, to have "unsaturated-type" fatty acid spectrum biosynthetically different from the fatty acid spectra of the former but similar to those of L. plantarum and other lactobacilli. No transitional fatty acid pattern between the two types could be detected among the tested intermediates. Feasibility of taxonomic discrimination of Bacillus- Lactobacillus intermediates by examination of the cellular fatty acid spectra was discussed.
Submerged shake cultures of Aspergillus nidulans produce conidia within 33hr of incubation under optimal growth conditions. Although the conidia are viable and are formed on normal structures, they lack the green pigment. Conidiating shake cultures turn the media yellowish brown. Although conidia germinate even in the absence of inorganic salts in the minimal medium, mycelium formation is inhibited. In a medium deficient in KCl, small hard ball-like colonies are formed. On being transferred to a normal medium, all the germinated conidia or abnormal colonies give rise to normal colonies with normal conidial heads. Colonies grown in liquid media for a long time are capable of producing cleistothecia very quickly. The importance of these observations has been discussed.