- Volume 98, Issue 2, 1977

Summary: Germination of Syncephalastrum racemosum sporangiospores was studied in shake flask and batch fermenter cultures. In the presence of glucose, spore swelling preceded outgrowth of germ tubes; dry weight increased markedly only at the time of germ tube emergence. Glucose was essential for initiation of these events. Both swelling and germ tube emergence quickly ceased when glucose-grown cultures were shifted down to non-permissive glucose-free medium. Spore swelling was not a prerequisite for germ tube emergence. Analysis of size distributions within populations of partially germinated spores indicated that larger spores germinated first.

Summary: In the presence of K+, Na+ enhanced respiration and activated cellular motility and transport of K+, amino acids and phosphate in Pseudomonas stutzeri. Inorganic phosphate taken up was rapidly esterified to nucleoside triphosphates and diphosphates. Respiration and phosphate transport showed cooperative responses to Na+ which increased with temperature. Respiration was more sensitive to polymyxin B in the presence of Na+. Dinitrophenol and carbonyl cyanide p-trifluoromethoxy-phenylhydrazone stimulated respiration when either Na+ or K+ was absent, but not in the presence of both cations. Therefore, Na+ is essential for the cytoplasmic membrane of P. stutzeri to perform energy-linked functions coupled to respiration.

Summary: The rate of accumulation of ammonium ion in cultures of Ureaplasma urealyti-cum was independent of the growth rate and of the initial urea concentration above 0·025% in the medium, although the quantity of ammonium ion accumulating did depend on the initial urea concentration. Ammonium ions accumulated at a similar rate in U. urealyticum cultures of both rapidly and slowly growing organisms. Viable but non-growing ureaplasmas also produced ammonia in complete medium at a lower temperature than usual (25°C) or in an inadequate growth medium at 37°C. The rate of ammonium ion accumulation in a dying culture depended on the number of viable organisms present; this is relevant to diagnostic methods for ureaplasmas which depend on detecting ammonia colorimetrically.

Summary: The abilities of 26 marine and 12 other Pseudomonas-like strains of bacteria to grow on single carbon sources, their antibiotic sensitivities and complement of some enzymes of intermediary metabolism were numerically analysed and gave five phenons. Two phenons contained strains with more than 55 mol % GC and were regarded as Pseudomonas spp., two were similar to the genus Alteromonas, and one was an intermediate phenon. Tests for identifying such organisms are proposed. Pseudomonas putrefaciens Derby & Hammer 1931 and P. rubescens Pivnick 1955 should be considered synonyms of Alteromonas putrefaciens Derby & Hammer comb. nov.

Summary: Numerical analysis of the relationships among rapidly growing, scotochromogenic mycobacteria was carried out; a dendrogram was prepared by a single linkage method and the separation between species was tested. The following were distinct species: Mycobacterium aichiense; Mycobacterium rhodesiae; Mycobacterium chubuense; Mycobacterium obuense; Mycobacterium gilvum; Mycobacterium duvalii; Mycobacterium flavescens; and Mycobacterium vaccae. Mycobacterium tokaiense was reduced to a synonym of M. chubuense. Mycobacterium parafortuitum, Mycobacterium aurum and Mycobacterium neoaurum were considered to be subspecies of M. parafortuitum or part of a M. parafortuitum complex.

The separation between species was tested by comparing the extent of overlap of one species with that of another. When two species showed no such overlap, they were regarded as distinct. The results of the test of separation agreed well with taxonomic relationships shown by the dendrogram. Characters useful for differentiating the spscies were found.

Summary: Esterases of 85 strains of the four biochemically-defined subgenera of Salmonella, when analysed by the acrylamide-agarose zymogram technique using several synthetic substrates, gave four principal bands (E1, E2, E3, E4) and two minor ones. The E1 esterase band hydrolysed α-naphthyl acetate, whereas the E2 band hydrolysed β-naphthyl acetate. These bands were resistant to di-isofluoropropyl phosphate (DFP) and their electrophoretic distribution among the strains occurred within a relatively small MF range, MF being the distance moved by the esterase band as a percentage of the distance moved by the dye front. The E3 band hydrolysed α-naphthyl acetate and α-naphthyl butyrate and, to a lesser degree, β-naphthyl esters, whereas the E4 band hydrolysed α-naphthyl acetate. These bands were sensitive to DFP and their electrophoretic distribution among the strains occurred in a wide MF range. All Salmonella strains were closely related in terms of their esterase profiles. However, the divergences in electrophoretic distribution of bands E3 and E4 were sufficient to recognize the subgenera of most of the Salmonella strains analysed.

Summary: Esterases of 42 strains of Levinea malonatica, Levinea amalonatica and Citrobacter were analysed by horizontal slab electrophoresis in polyacrylamide-agarose gel using several synthetic substrates. On the basis of esterase zymograms a distinctive pattern was established for each of the three species. Levinea malonatica was characterized by two major bands: one hydrolysing acetate esters but not butyrate esters; and the other hydrolysing α-naphthyl acetate and reacting weakly with β-naphtyl butyrate and α-napthyl acetate. Levinea amalonatica showed one prominent band that hydrolysed α-naphthyl esters and reacted weakly with β-naphthyl esters. Citrobacter strains showed one major band that hydrolysed α-naphthyl esters and appeared slightly more active towards β-naphthyl esters than that of L. amalonatica. Considerable variations in electrophoretic mobility were observed among Citrobacter strains. Levinea amalonatica was less variable. In addition, one minor anodal band reacting with β-naphthyl acetate was observed in both L. malonatica and Citrobacter.

The relative molecular sizes of the major esterase bands were determined by disc electrophoresis with gels of different acrylamide concentrations. The molecular size of the major band of Citrobacter appeared to be smaller than that of the corresponding esterase band of L. amalonatica.

Summary: Nutritional tests on yeasts which utilize myo-inositol as the sole carbon source or which have red pigment have been carried out on deined media solidified with silica gel (Ludox HS-40) in multicompartment polystyrene dishes. Yeasts of the above types isolated from soft fruits were tested together with 189 named strains representing 28 genera and 110 species and varieties. The results obtained were compared with those for growth on media solidified with several commercially prepared agars. Methods are described for purifying commercial samples of Ludox HS-40 and for removing contaminating sugars from some di-and trisaccharides used in the tests.