- Volume 26, Issue 1, 1961

SUMMARY Three filamentous micro-organisms are described. They are typical Actinomycetales forming branching hyphae, 1.5 μ or less in diameter, which are differentiated into a substrate (primary) mycelium and an aerial (secondary) mycelium. They have an unusual mode of sporulation since they form chains of conidia both on the substrate and on the aerial mycelium. A new genus, Micropolyspora, is proposed. The type species is M. brevicatena. The new genus is part of the family Actino-mycetaeeae. The abolition of the family Streptomycetaceae is proposed.

SUMMARY Biochemical mutants of Actinomyces aureofaciens were obtained after treatment with ultraviolet irradiation or ethyleneimine. A specificity of the mutational process in a series of A. aureofaciens strains was observed, revealing itself mainly in formation of arginine-requiring mutants. Prototroph formation was shown to result from crosses of A. aureofaciens biochemical mutants with either the same or different amino acid requirements. Colonial morphology and antibacterial activity of some prototrophs were studied.

SUMMARY A new species and genus of colourless sulphur bacteria, for which the name Thiodendron mucosum is proposed, is described from two habitats in Florida. Its morphology and physiology relate it to the Beggiatoaceae, but it is branching, non-filamentous and non-motile so it should not be included in that family and a new family should be created for it. Some characteristics of its environment are discussed and also the organisms common to such an environment. It is probable that the particular organisms are closely connected to the metabolism of sulphur, while their variety and biomass attribute an important role to sulphur in nature, especially in environments containing little or no oxygen.

SUMMARY A new species of Torulopsis is described; it was isolated from a Finnish soil. This species is named T. castellii in honour of Professor Tommaso Castelli of the Agricultural university of Perugia, Italy.

SUMMARY A modification of glucose cysteine blood agar (GCBA) is described for the cultivation of Pasteurella tularensis in which the blood is replaced by plasma and catalase. It has the advantage for colony counting of being clear, and is at least as good as GCBA for enumerating fastidious aged P. tularensis suspensions and aerosols. The liquid medium supports the growth of very small inocula.

SUMMARY Factor I of the anthrax toxin was isolated and showed one major component in the ultracentrifuge and on paper electrophoresis; it contained less 5.5% of extraneous antigens detectable by serological precipitation in gels. The final preparation contained all the usual amino acids (N = 10.1%) and some carbohydrate (6%, calculated as glucose) and phosphorus (0.7%). The most striking aspects of its analysis were a high ash (10-13%) and a light absorption at 260 mμ. The high ash was not due to one element but to a highly variable metal content (mainly Ca, Mg, Ni, Cu) indicating a powerful and indiscriminate chelating action of factor I. This chelating action might have been due to the chemical entity which absorbed light at 260 mμ and which was not RNA or DNA.

The final preparation of factor I was not toxic when injected alone but when mixed with purified factor II it evoked oedema in the skin of a rabbit and killed mice. However, the concentrationof this mixture which killed mice formed a much larger skin reaction in rabbits than a comparable dose (based on mouse LD 50) of either curde toxin or a mixture of crude factors I and II. An investigationof this fact led toteh demonstraion and partial purification of a third factor (III) of the anthrax toxin which: (1) was different serologically from factors I and II; (2) was present in anthrax toxin produced in vivo; (3) was non-toxic when injected alone; (4) was lethal for mice when mixed with factor II but not with factor I; (5) increased the lethality of mixtures of factors I and II for mice and decreased their capacity to produce oedema in the skin of rabbits. A mixture of factors I, II and III showed synergic action in toxicity tests in mice; the mixture killed guinea pigs which showed signs of ligaemic secondary shock (as did guinea pigs killed by anthrax infection).

SUMMARY Investigations were made of the transformations undergone by the stereoisomers of α,ɛ-diaminopimelic acid in suspensions of acetone-dried organisms of two species of sporulating bacteria, Sporosarcina ureae and Bacillus sphaericus, both of which contain diaminopimelic acid in their spores but not in their vegetative cells. Meso-diaminopimelic acid was rapidly decarboxylated by vegetative organisms of both species; it was also utilized by some other unidentified anaerobic reaction. The vegetative organisms also oxidized meso-diaminopimelic acid with release of ammonia. l-Lysine was oxidized by S. ureae, but not by B. sphaericus. Neither ll-nor dd-diaminopimelic acid was attacked by either organism.

Disintegrated spores of Bacillus sphaericus did not oxidize meso-diaminopimelic acid, but decarboxylated it and also utilized it by the unidentified anaerobic reaction. The decarboxylation, but not the oxidation, of diaminopimelic acid by Sporosarcina ureae was greatly stimulated by pyridoxal phosphate; both reactions were inhibited by the same compounds. Study of the oxidation was complicated by the side reactions which occurred with S. ureae, but a simpler system was provided by an asporogenous variant of B. sphaericus which did not decarboxylate diaminopimelic acid without added pyridoxal phosphate. Only one equivalent of ammonia was produced, a small amount of CO2 was evolved and two equivalents of oxygen were utilized; no oxidation product was identified. The methods of attacking diaminopimelic acid by these two atypical species are compared and discussed in relation to other species in their respective families.

SUMMARY The interaction of the anionic lipopolysaccharide complex isolated from a Gram-negative bacterium (Serratia marcescens) was studied in aqueous and saline solution with several cationic macromolecules, with the object of selectively inhibiting certain of the biological activities of this polysaccharide endotoxin. Incubation with lysozyme decreased the pyrogenic activity, while the tumour-damaging ability of this polysaccharide remained high. This was in contrast to interaction with RNase and with polymyxin B, in which cases the tumour-damaging activity was decreased while the pyrogenic activity was not affected. Ultracentrifuge experiments indicated that both the tumour-necrotic and especially the fever-producing fractions of this bacterial polysaccharide preparation are of much higher molecular weight (> 10S) than the major component (3.4S), which is either inactive or of low activity. The highest molecular weight fever-producing components appeared to be broken down in an enzymic type of process by the lysozyme.

SUMMARY In studying 8 strains of Mycobacterium tuberculosis and 7 strains of atypical mycobacteria all 15 were found to produce, in addition to the typical acid-fast cells, non acid-fast ones, which gradually developed intracellular spore-like bodies; later free-lying spores were seen in the same cultures. This process occurred in heavily inoculated Löwenstein–Jensen medium cultures, which were at least 8 weeks old and were frequently aerated during incubation. With the atypical mycobacteria it occurred more readily in cultures in Kirschner fluid medium than on solid media. When the cultures containing spores were inoculated on nutrient agar plates, endospore-forming, rapidly growing organisms were obtained, which were not acid-fast. These organisms when obtained from independent cultures of the same strain appeared to be identical in bacillary and colonial morphology at their first isolation on nutrient agar, but the organisms from different strains showed variation in these characters. Thus mycobacteria appear able to grow in two different forms: (a) form 1, which is acid-fast and multiplies by fission only; (b) form 2, which is not acid-fast, produces endospores regularly and can be maintained in pure culture on nutrient agar. A series of phases of development of form 2 cells in the cultures of form 1 organisms in serial smear examination of Löwenstein–Jensen medium cultures is described. It is suggested that mycobacteria might be considered as dimorphic organisms in the same sense as some of the human pathogenic fungi are known to be dimorphic. Evidence is submitted that form 2 organisms are not contaminants.

SUMMARY Two distinct temperate phages (594a, 594n) lysogenizing phage type 80/81 staphylococci and producing gains in sensitivity to typing phages 52 and 52A were found in lysogenic clones of a strain of staphylococcus of phage type 52/52A/80/81. When either of these phages infected type 80/81 cocci a new phage (594b) appeared in the lysates. This phage was unable to replicate in type 80/81 cocci but could grow in them when they had been lysogenized with phage 594a or 594n. The source of phage 594b was found to be recombination of phage 594a or 594n with a prophage present in cocci of phage type 80/81. This prophage was completely defective and could be demonstrated only by recombination. The gains in phage sensitivity that follow lysogenization of type 80/81 strains with the so-called ‘converting’ phages can be most satisfactorily explained on the basis of prophage substitution.

SUMMARY Pseudomonas maltophilia is frequently encountered in specimens submitted to the clinical laboratory for bacteriological examination. This report describes morphological, physiological and serological attributes of this species. Photomicrographs show the presence of polar multitrichous flagella in stained preparations. These pseudomonads do not produce acid from glucose but readily produce acidity from maltose oxidation. A historical review of the epithet Alcaligenes bookeri is presented.

SUMMARY The cultural and physiological characteristics of some Xanthomonas spp. that are typical of the genus were compared with two atypical species, Xanthomonas uredovorus and X. stewartii. Electron microscopic studies of X. uredovorus, prepared by two methods, show that this organism possesses peritrichous flagella. This fact, together with evidence of the fermentative metabolism of carbohydrates, should exclude this bacterium from the genus Xanthomonas. The interpretation of electron micrographs is discussed, and the systematic position of X. uredovorus and X. stewartii.

SUMMARY Metschnikowiella zobellii sp.nov. and M. krissii sp.nov. are described and Latin diagnoses given. Both species form on V8 agar (Wickerham, 1951) club-shaped asci containing a single needle-shaped ascospore and are capable of parasitizing Daphnia magna under experimental conditions. M. zobellii differs from M. krissii by its capacity to ferment glucose and to assimilate galactose, l-sorbose, d-xylose, d-glucosamine, adonitol, d-sorbitol and pyruvate. In infected daphnias the asci and cells of both yeasts resemble Metschnikoff's drawings of M. bicuspidata. As cultures of M. bicuspidata do not exist and its physiological properties are unknown, the possible identity of either M. zobellii or M. krissii with M. bicuspidata cannot be verified and M. bicuspidata (Metschnikoff 1884) Genkel 1913 is therefore considered a nomen dubium. Both yeasts were repeatedly isolated from marine substrata on and off the coast of La Jolla, California, U.S.A. Minimum numbers of viable organisms in positive samples varied for M. zobellii as follows: sea water, 2–58/100 ml.; fish gut contents (of Atherinopis affinis littoralis and Trachurus symmetricus), 25–5,730/ml.; surface of Giant Kelp (Macrocystis pyrifera), 520–39,200/g. M. krissii was isolated only from sea water, 1–57/100 ml.

SUMMARY Fungi were isolated from soil under several vegetational types by an enrichment technique with vanillin or p-hydroxybenzaldehyde as sole source of carbon. Although similar morphologically, the isolates obtained are classified in two separate groups, yeasts and hyphomycetes. A study was made of the growth in pure culture of representative species, namely, Pullularia pullulans, Margarinomyces heteromorpha and M. mutabilis on several aromatic compounds related to lignin.

SUMMARY The metabolism of various lignin-related aromatic compounds by several soil Hyphomycetes and yeast-like fungi was investigated. Adaptation studies with whole organisms and cell-free extracts confirmed previously proposed metabolic pathways (Henderson & Farmer, 1955; Henderson, 1960). It was shown that protocatechuic acid is an intermediate in the metabolism of vanillin and ferulic acid. Protocatechuic acid oxidase activity of cell-free extracts of Pullularia pullulans was found to be stimulated by ferrous ions and to depend on –SH groups.

SUMMARY Four phages isolated from bacteria of the Bacillus cereus group are described. They show cross-reactions between crystal-forming and non-crystal-forming strains which are deficient in ability to produce a lecithinase C. The implications of this finding are discussed.