Zentralblatt für Bakteriologie Mikrobiologie und Hygiene: I. Abt. Originale C: Allgemeine, angewandte und ?kologische Mikrobiologie最新文献

Fatty acid and menaquinone patterns as well as the sugar composition and the presence of L,L-diaminopimelic acid in cells of Actinoplanes armeniacus indicate a closer relatedness of this species to members of Streptomycetaceae than to those of Actinoplanaceae. This is further supported by the sensitivity of A. armeniacus to polyvalent Streptomyces- und Kitasatoa-phages. DNA-DNA reassociation studies reveal a definitely higher DNA homology of A. armeniacus to representatives of various streptomycete genera than to those of Actinoplanes and related genera. The reassociation data, however, do not allow unambigous allocation of this species to one of the described genera of Streptomycetaceae.

Two types of anaerobic extremely thermoacidophilic bacteria have been isolated from more than 50% of the samples collected in solfataric fields throughout Iceland.

They both possess highly stable cell envelopes with a characteristic subunit structure, are usually rods of variable length (about 1 to more than 50 μ) without septa, but can give rise to spheric bodies which exist either attached to the rods or in free state. Under certain conditions, truly branched filaments are frequently observed. The similarities in morphology and growth characteristics indicate that the two types are related to each other. In view of its variable appearance the larger organism (diameter about 0.4 μm) was called Thermoproteus tenax.

Thermoproteus tenax forms H₂S and CO₂ from elemental sulfur and organic substrates, like glucose, ethanol, malate or formamide.

The absence of murein, the presence of polyisoprenoid ether lipids, the complete resistance against the antibiotics rifampicin, streptomycin, vancomycin and chloramphenicol and the component pattern and rifampicin insensitivity of the DNA-dependent RNA polymerase are evidence that Thermoproteus tenax belongs to the archaebacteria. It represents a novel order of the thermoacidophilic branch of this urkingdom.

The DNA-DNA homology of 71 strains of Pediococcus isolated from Italian cheeses with Pediococcus pentosaceus NCDO 1220 and P. acidilactici ATCC 25742 was determined.

Twenty-seven of the 34 strains isolated from Grana are affiliated to P. acidilactici but only 7 to P. pentosaceus. Of the 24 strains isolated from Pecorino Romano 5 strains showed a high percentage of DNA-DNA homology with P. acidilactici and 19 with P. pentosaceus. All the other strains isolated from Provolone, Casera Valsassina and Canestrato Siciliano Pepato belong to the species P. pentosaceus.

The labeling kinetics of early products of heterotrophic and autotrophic ¹⁴CO₂ fixation in Sulfolobus brierleyi have been studied. Glutamic acid and glutamine were the dominating labeled compounds after 30 sec and 10 min of heterotrophic ¹⁴CO₂ fixation, with only small portions of ¹⁴C detectable in aspartic acid, alanine and an unknown compound Z. Malic acid, citric acid, glutamic acid, aspartic acid and an unknown compound X were the compounds most rapidly labeled during short time autotrophic ¹⁴CO₂ fixation.

It is concluded that the heterotrophic CO₂ fixation of S. brierleyi is based primarily on an exchange between the α-carboxyl group of α-keto-glutaric acid and ¹⁴CO₂, whereas the autotrophic ¹⁴CO₂ fixation of this organism leads to a true net assimilation of carbon via a reductive carboxylic acid pathway with malic acid, citric acid, aspartic acid, glutamic acid and the unknown compound X as early products. The participation of pyruvate is doubtful, since alanine is only slowly labeled. The evolutionary implications of these findings are discussed.

It is suggested that a reductive carboxylic acid pathway, of which various modifications exist at present in Chlorobium, an early unique branch of the eubacteria and in both groups of autotrophic archaebacteria (methanogenic bacteria and Sulfolobus) may be a common heritage of all organisms, whereas the Calvin-Benson cycle was “invented” at an early evolutionary stage of the gram-negative eubacteria.

The first communication reported on the bacterial flora isolated from 4 different French non-carbonated bottled mineral waters with reference to the colony counts, rough composition of the bacterial flora and to the group of gram-negative, yellow-pigmented bacteria.

This second communication is a study of the Pseudomonas group and other gram-negative bacteria and describes the refined composition of the flora in more detail.

A differentiation of the Pseudomonas group was achieved by means of nearly 30 biochemical and physiological tests. Altogether 467 strains of Pseudomonas could be subdivided into 4 groups according to their 4 main characteristics: the production of a fluorescent pigment, the presence of a dehydrolase of arginine, oxidative metabolism of glucose and alcalinisation of the medium. 261 strains belonging to group I (Pseudomonas facultatively fluorescent and arginine-positive) and 18 strains of group II (non-fluorescent, arginine-negative and oxidative glucose metabolism) were easily identifiable. Group III with 95 strains (no glucose oxidation) and group IV with 93 strains (alcalinisation of the media) were more heterogenic and did not show evidence properties typical of Pseudomonas species.

The so-called “AAM” group (Acinetobacter-Alcaligenes-Moraxella) was differentiated from the other gram-negative bacteria on the basis of 2 criteria: mobility and oxidase reaction.

The distribution of the isolated bacterial flora — including the yellow pigmented bacteria — in the 4 mineral waters was then determined in terms of a percentage of each group and subgroup, as well as according to a more realistic logarithmical presentation of the number of colonies of these groups.

Each water has its own distinguishing “finger print”, although each group of bacteria is present in all 4 mineral waters to a varying extent. The analyses of water 1 and 3 weeks after bottling did not reveal any marked differences either with respect to the colony counts or regarding the representation of the different groups.

In all the mineral waters the majority of strains were slow to very slow growing this being physiologically typical for the isolated bacteria of mineral water.

La première communication traitant de la flore bactérienne isolée de quatre eaux minérales non gazéifiées et mises en bouteilles avait porté sur le dénombrement de colonies, la composition grossière de la flore ainsi que sur le groupe des bactéries gram négatif et pigmentées en jaune.

La seconde partie se penche tout d’abord sur les Pseudomonas et autres bactéries à gram négatif et résume ensuite la composition fine de la flore.

Une differentiation fine du groupe des Pseudomonas a été réalisée à l’aide de près de 30 tests biochimiques et physiologiques, L’ensemble des 467 souches de Pseudomonas a pu être subdivisé en 4 groupes à l’aide de 4 c