Growth of corn stunt spiroplasma (CSS) in a medium containing 0-47 mM arginine increased with increasing arginine concentrations. Plotting specific growth rates of CSS at 0-94mM arginine resulted in a hyperbolic curve. At low arginine concentrations, specific growth rates of CSS were proportional to arginine concentrations; maximum growth rate occurred at 47mM arginine. Numbers of cells and colony-forming units in medium with 47mM arginine were two-fold greater than in medium without arginine. Helicity of CSS in medium with 0, 12, 24, and 47 mM arginine was lost by 8, 12, 14, and 15 days, respectively, after inoculation. Helicity was restored to 8-day-old cultures by addition of 47mM arginine. The growth-stimulating effect of arginine was inhibited or obscured when 10-20% serum was added to the medium. Addition of rifampicin also inhibited the growth-stimulating effect of arginine.
Our probabilistic view of the colony formation on a plate has led to the hypothesis that the parameter λ in the colony forming equation previously presented reflects the physiological state of a bacterial population. In the present work, the hypothesis was examined with single populations of organisms isolated from soil. These populations showed λ values larger than 1.0 day-1 when grown on a growing medium and less than 0.5 day-1 after starvation in water for several weeks or more. The latter values were similar to those of various soil populations. Cells with a smaller λ proliferated at a lower probability than those with a higher λ. Physiological states corresponding to a λ larger than 1.0 day-1 and less than 0.5 day-1 are designated g and s states, respectively. The transition of cells between the g and s states is discussed.
The cellular fatty acids and the quinone systems were investigated in 46 strains of Pseudomonas species including 14 phytopathogenic Pseudomonas strains, In a total of 75 strains, including 46 strains in this study and 29 strains reported in previous papers, Pseudomonas species showed heterogeneity in fatty acid composition and in the ubiquinone system. They were divided into nine groups according to these characteristics, with special reference to the existence of 3-hydroxy fatty acids. The significance of 3-hydroxy fatty acid composition in the classification of Pseudomonas species is discussed.
Gas chromatographic analyses of Norman Wells crude oil were used to determine its biodegradability in oil-contaminated cultures containing the ciliate Colpidium colpoda and a mixture of oil-degrading bacterial species. Within these cultures the specific growth rates (b) of Colpidium ranged from 0.018 to 0.026/hr while maximum cell densities were-3, 000 cells/ml. Similarly, high numbers of oil-utilizing bacteria (up to 3.86 ×108cells/ml) were maintained throughout the experimental period. Ratios of the n-C17/pristane and n-C18/phytane peak heights were used to assess biodegradation. Ratios in bacterized treatments without ciliates incubated for 31, 43 and 54 days were slightly lower than their respective control values. Conversely, pronounced decreases in these ratios were apparent in cultures containing both bacteria and ciliates. Therefore, the presence of Colpidium colpoda enhanced the in vitro microbial degradation of crude petroleum.
Forty-four strains of 26 species of yeasts and yeast-like fungi were examined for the Co-Q system as a taxonomic criterion. In the Hemiascomycetes of Ascomycotina, Cephaloascus fragrans had the Q-9 system. Protomyces inouyei, P. lactucae-debilis, P. pachydermus and Taphrina wiesneri showed the Q-10 system. That system occurred also in the basidiomycetous yeasts, Filobasidium floriforme and Sporidiobolusjohnsonii; and in the Hymenomycetes of Basidiomycotina, Tremellaaurantia, T. brasiliensis, T. encephala, T. foliacea, T. fuciformis, T. mesenterica, T. subanomala and Femsjonia luteoalba. In the Blastomycetes of Deuteromycotina, the Q-9 system occurred in Selenozyma intestinalis, Sterigmatomyces elviae and Trigonopsis variabilis. Other species such as Cryptococcus hungaricus, Bullera alba, Itersonilia perplexans, Tilletiopsis cremea, T. lilacina, T. minor var. minor and T. minor var. flava had the Q-10 system. In the Hyphomycetes of Deuteromycotina, Aureobasidium pullulans exhibited the Q-10(H2) system, however, Rhinocladiellamansonii presented the Q-10 system. The taxonomic significance of the Co-Q system is discussed.
Coryneform bacteria with LL-diaminopimelic acid in the cell wall were characterized. Morphological, biochemical, and chemotaxonomic characteristics, and DNA homologies revealed that they form an independent cluster among the coryneform bacteria. A new genus Pimelobacter is proposed for this group of coryneform bacteria. The type species of the genus Pimelobacter is Pimelobacter simplex comb. nov., which was previously named Arthrobacter simplex. Further, Pimelobacter jensenii sp. nov. and Pimelobacter tumescens comb. nov. are also described.