- Volume 70, Issue 2, 1972

Ultraviolet spectroscopy, partition chromatography and mass spectroscopy showed that the only quinone isolated from Bacillus brevis was menaquinone-7. The concentration of quinone present in electron-transport particles was consistent with its participation as an oxido-reduction component. Loss in NADH oxidase activity after ultraviolet irradiation or pentane extraction correlated with the degradation or removal respectively of menaquinone-7 present in the electron transport particles. Attempts to restore NADH oxidase activity either with ultraviolet-treated or pentane-extracted particles using the natural menaquinone were unsuccessful, although lower menaquinone homologues stimulated activity.

SUMMARY: A phage-induced enzyme has been used to hydrolyse the exopolysaccharides prepared from nine Klebsiella serotype 2 strains. In each case, the major product was a tetrasaccharide with chemical composition corresponding to the carbohydrate repeating unit of the polysaccharide. The tetrasaccharides also contained formate, sometimes with acetate or pyruvate. As the terminal reducing sugar in each tetrasaccharide was mannose, the enzyme is a mannosidase hydrolysing the d-mannosyl 1 → 4 d-glucose linkage.

The enzyme is highly specific, being inactive against carboxyl-reduced type 2 polysaccharide and against polysaccharides from a number of other Klebsiella strains of different serotype. In contrast, similar phage-induced enzymes from Klebsiella aerogenes serotype 54 strains hydrolyse both type 2 and type 54 polysaccharides, yielding the same products from type 2 material as does the homologous enzyme. No further polysaccharides among those currently tested acted as substrates for the phage-induced enzymes.

3-Amino-3,6-dideoxy-d-galactose has been identified as a component of the wall of Pseudomonas ftuorescens (nctci 10038). This amino sugar was present in the lipopolysaccharide fraction of the wall: other amino compounds present were glucosamine, galactosamine, quinovosamine, alanine and ethanolamine. The distribution of amino sugars within different regions of the lipopolysaccharide was studied briefly.

Vertical ultrathin sections of a colony of Mycoplasma orale serotype 1, n-1 strain, which had been isolated from a patient with leukaemia, have been examined by electron microscopy.

In the micrographs, the ultrastructural appearance of Mycoplasma orale in agar growth could be divided into two patterns. One was a mycelial growth form which was observed in the surface area and resembled growth in broth. The other was a pattern of binary fission observed in the deep area of the agar. These growth features differ from those of human mycoplasmas previously reported.

SUMMARY: A sensitive, small-scale assay for penicillin showed the production of penicillin in sterilized but otherwise unsupplemented soils inoculated with a wild-type Penicillium chrysogenum. The same Penicillium was capable of competitively invading maize seeds equilibrated at 95 % relative humidity, and producing penicillin in the seed. Problems with gross contamination of some batches of seeds were overcome by the use of surface-sterilization.

The hypothesis that the natural function of β-lactamase is the detoxification of penicillins has been tested by measuring the survival or growth of mixtures of micro- and magno-constitutive β-lactamase-producing Bacillus cereus in an environment containing naturally produced penicillins. The magno-constitutive strain had a clear survival advantage which was abolished or greatly reduced if minute quantities of purified β-lactamase were added, in which case the micro-constitutive seemed at a slight advantage.

SUMMARY: The collagenolytic activity of no aerobic halophilic and halotolerant bacterial strains isolated from cured hides was determined. At 2·34% (w/v) NaCl, 10% of the bacterial strains could denature purified collagen. Collagenolytic activity was not detected at 7 % (w/v) NaCl. Three of the collagenolytic strains were identified as Bacillus spp. and eight as Achromobacter spp. Nine of these eleven bacteria were also gelatinolytic. Australian hides which produce decay-free leather lacked collagenolytic bacteria.

Clone cultures of two strains of the rumen organism Eadie’s Oval were established in vitro. Both strains were maintained anaerobically at 38 to 40° in liquid culture in the presence of bacteria, rumen fluid, a reducing agent and a CO2 gas phase. There was no growth in sterile or solid media. Growth and storage of glycogen occurred when each strain was incubated with one of a small range of simple carbohydrates; amino acids, fatty acids, proteins and polysaccharides did not support growth or glycogen synthesis. Neither strain survived freezing, but cultures were viable after two weeks at 4°; incubation at 44° resulted in no growth or the death of cultures.

Pyronin Y (0·06 and 0·16 mm), coumarin (2 and 4 mm), 6,9-dimethyl 2-methyl-thiopurine (2 mm) and caffeine (8 mm), strongly inhibit Uvr repair (presumed excision repair) of u.v. lesions in Escherichia coli. With 0·16 mm-pyronin Y or 4 mm-coumarin, one thymine dimer was a lethal event in the k12 strain jc2926 rec A-13 and one to three dimers in the b/r derivative wp-2 rec A-13 and the b exr A derivative bs-2. Neither these compounds nor 8 mm-caffeine had a significant effect on the survival of irradiated bacteria of the corresponding uvr strains wp-2 Hcr−, bs-12, and bs-8. I suggest that 8 mm-caffeine, 0·16 mm-pyronin Y, 4 mm-coumarin and 2 mm-6,9-dimethyl 2-methylthiopurine selectively block excision repair without substantially affecting recombination repair.

Caffeine at 12 mm only slightly depressed the viability of a u.v.-irradiated culture of wp-2 Hcr− or bs-12, but at 16 mm there was a much greater effect, particularly at low u.v. doses (< 40 ergs/mm2). Since excision repair appeared to be effectively blocked by 8 mm-caffeine, the depression of u.v. survival of the uvr mutants by 16 mm-caffeine was presumed to be due to interference with recombination repair (Witkin & Farquharson, 1969).

SUMMARY: Mutants of Pseudomonas aeruginosa were isolated which grew with acetanilide (N-phenylacetamide) as the sole carbon source for growth. The mutants could also use acetanilide as a nitrogen source but grew better in the presence of ammonium salts. The acetanilide-utilizing mutants produced amidases which differed in substrate specificity and electrophoretic mobility from the wild-type A amidase and the B amidase produced by a butyramide-utilizing mutant. The amidase from one of the acetanilide-utilizing mutants was purified and shown to differ from the wild-type enzyme by the substitution of an isoleucine for a threonine residue.

The possession of flagellar hooks by non-flagellate mutants derived from phase 1 stable strains of Salmonella abortusequi was determined by electron microscopic examination of material detached from these bacteria by mechanical means. Hooks were found in all the preparations from H1 mutants but none in those from fla mutants representative of fourteen different complementation groups. The hooks from H1 mutants were morphologically indistinguishable from those of wild-type. These results show that all the fla genes are involved in hook formation and that the flagellin structural gene H1 is not.

SUMMARY: Abortive transduction of motility has been demonstrated with all members of the Proteus-Providence group of bacteria.

SUMMARY: A study of the ultrastructural characteristics, the physiological properties and an analysis of hydrolysates of phenol-treated cell walls of Corynebacterium rubrum were made. While the arabinogalactan-peptidoglycan complex found in the cell- wall hydrolysates was that common to the genera Corynebacterium, Mycobacterium and Nocardia, the ultrastructural patterns found, the physiological reactions observed, the sensitivity to nocardiophages but not to corynebacteriophages or mycobacterial phages, and the (previously reported) presence of nocardomycolic acids, combined with the absence of corynemycolic acids and mycolic acids, indicate that this species belongs in the genus Nocardia rather than in the genus Corynebacterium.

It is proposed, therefore, that Corynebacterium rubrum be renamed Nocardia corynebacteriodes nomen novum.

The ability to protect mice against intracerebral infection and to elicit, after one dose, complement-mediated bactericidal antibody capable of killing a mouse-virulent phase I strain in vitro, was tested in seven cultures of Bordetella pertussis: three typical phase I strains; two strains grown in the presence of 0·5 mg nicotinic acid/ml; one phase IV strain; and the atypical strain 134. The typical strains showed both activities; the nicotinic acid-grown and phase IV strains elicited high antibody titres, but did not confer protection, whereas strain 134 protected, but did not elicit bactericidal antibody.

Pyrogenic material extracted from dried organisms by hot phenol and water (lipopolysaccharide) was not antigenic in mice; however, with all strains, except 134, multiple doses of this material coupled to stromata or Escherichia coli conjugated protein elicited bactericidal and precipitating antisera in mice, although the mice were not protected.

Strain 134 contained approximately one quarter of the normal amount of endotoxin, as assayed in actinomycin d-sensitized mice, but was as effective as normal strains as an adjuvant for haemolysin production.

SUMMARY: The ATP pool, chosen as a suitable criterion of the cellular energetic state, has been measured in Zymomonas mobilis in different physiological conditions. ATP accumulates when growth is limited by pantothenic acid or blocked by chloramphenicol. A constitutive ATPase activity with a low affinity for ATP has been found which could be responsible for the dissipation of the excess energy produced in uncoupling conditions of growth.