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

The cytochrome components of membrane fractions isolated from logarithmic and stationary phase cells of representative strains of staphylococci and micrococci were investigated. Reduced minus oxidised difference spectra at the temperature of liquid nitrogen (77°K) were carried out to determine the wavelength of the α-peaks of the cytochromes. In addition, the maxima of cytochromes occurring only in low concentrations were determined by employing the second derivative of the difference spectra.

The investigation of the cytochromes of the micrococci revealed the presence of a-, b-, c- and d-types, that of the staphylococci revealed only a- and b-types. Only Staphylococcus sciuri differs from this general rule, as it also exhibits c-type cytochromes, although in contrast to the micrococci it contains, like the staphylococci, no cytochrome d. According to the characteristic differences in their cytochrome-pattern, staphylococci can be clearly separated from micrococci.

A DNA-DNA hybridization study was carried out on a new group of Enterobacteriaceae (group H₁). The highest relative binding ratios were found with the species E. cloacae (37 to 61%) and K. pneumoniae (44 to 60%), The labelling of E. cloacae CUETM 77–120 and K. pneumoniae CUETM 77–169 DNA showed 27 to 32% and 20 to 35%, respectively, of relatedness with the group H₁. According to phenotypic data (numerical taxonomy) and genetic data (GC%, DNA/DNA hybridization and relative genome size: K. pneumoniae CUETM 77–169: 100, E. cloacae CUETM 77–120: 80, group H₁ CUETM 77–130: 58), the group H₁ represents a new species to be called Enterobacter intermedium.

The distribution of ¹⁴C among and within the fermentation products formed by the fermentation of specifically labelled glucose by cellulomonades was in the main found to be compatible with a glucose breakdown via the Embden-Meyerhof-Parnas pathway. However, ¹⁴C-acetic acid labelled in both carbon atoms was formed when 3-¹⁴C- or 3.4-¹⁴C-glucose was fermented. In addition, lactic acid formed from 1-¹⁴C-, 2-¹⁴C- or 6-¹⁴C-glucose contained significant amounts of label in the carboxyl group. This non-glycolytic 14C-distribution is not caused by an additional, hitherto unknown catabolic pathway. It is, however, the result of a very effective symmetric interchange and an asymmetric redistribution of carbon atoms within the hexose molecule caused by the reversible action of aldolase, transaldolase and transketolase on sugar phosphates before their final breakdown. Up to the present, such randomization processes have been observed only in algae, plants and animal tissues.

Ribosomes from the following strains of methanogenic bacteria were isolated and their protein patterns analysed by twodimensional polyacrylamide gel electrophoresis: Methano-sarcina (Ms.) barkeri (DSM 800); Ms. barkeri (morphotype II) (DSM 1232); Methanococcus (Mc.) vannielii (DSM 1224); Methanobacterium (Mb.) thermoautotrophicum (DSM 1053); Mb. arbophilicum (DSM 1125); Mb. formicicum and Mb. strain M. o. H. Ribosomes from Ms. barkeri were analysed in more detail. They possess an apparent sedimentation constant of 70S and dissociate at 1 mM Mg⁺⁺ into 30S and 50S subunits. Electropherograms of 30 S subunits purified twice on sucrose gradients exhibit at least 27 protein spots, those for 50S subunits at least 33. The individuality of these spots has not yet rigorously been determined. The electrophoretic pattern of the two strains of Ms. barkeri investigated differ with respect to a considerable number of proteins, which indicates a high degree of diversity even within one morphologically similar group.

The number of ribosomal proteins, as judged from the 70S electropherograms from other methanogens studied, lies in the typical “procaryotic” range, between 50 and 55. Striking, however, is the large number of acidic proteins in all strains, Their content is highest in Mb. arbophilicum, in which almost 2/3 of the proteins are acidic, and lowest in Mc. vannielii, of which about 1/3 of the total number of ribosomal proteins migrate to the anode. As ribosomes from extreme halophiles consist almost exclusively of acidic proteins, this unusual property is consistent with the comparatively high degree of 16 s RNA sequence homologies between halobacteria and one specific group (group I) of the methanogens (Magrum et al, 1978). Those species from group I investigated (Mb. arbophilicum; Mb. formicicum; Mb. strain M.o.H) also exhibit a qualitative resemblance in their ribosomal protein pattern; the patterns from Mb. formicicum and Mb. strain M.o.H are very similar. The practical value of ribosomal protein determination for the rapid identification or comparison of unclassified isolates is discussed.

DNA dependent RNA polymerase from Thermoplasma acidophilum was isolated by a procedure involving precipitation by polymin P, elution from the sediment, DEAE chromatography, heparin cellulose chromatography, sucrose glycerol gradient centrifugation and DNA cellulose chromatography. This technique has proved to be generally suitable for the isolation of RNA polymerase from Eubacteria and Archaebacteria and is probably also useful for Eukaryotes.

The purified enzyme consists of 7 components with the molecular weights 135000 108000, 56000, 35000, 22000, 13500 and 11500. The components with 56000 and 22000 daltons are absent from an incomplete inactive particle which can be separated from active enzyme by sucrose glycerol gradient centrifugation or DNA cellulose chromatography at low glycerol concentration. The component with 35000 daltons can be partially removed by DNA cellulose chromatography at high glycerol concentration and is not required for activity on poly [d(A – T) · d(A – T)]. The optimal conditions for the transcription of poly [d(A – T) · d(A–T)] and native phage DNA were determined. The activity on native phage DNA is only a few percent of that on poly [d(A – T) · d(A – T)]. It is stimulated by the addition of Mn⁺⁺ instead of Mg⁺⁺ ions and by removal of the component with the molecular weight 35000. The subunit pattern and composition are similar to those of the RNA polymerases of other Archaebacteria. The resistance against rifampicin, streptolydigine and α-amanitine is shared with all other known archaebacterial RNA polymerases.

A rod-shaped, gram-positive bacterium isolated from sauerkraut is described as a new species within the genus Lactobacillus, subgenus Streptobacterium, on the basis of physiological and biochemical features. This species is related to the Lactobacillus curvatus — Lactobacillus sake group but differs from these species by the formation of exclusively L( + ) lactic acid. According to the area of the isolation of the first strains, it has been named Lactobacillus bavaricus.

A group of 7 strains thus far classified as Lactobacillus acidophilus is considered to form a new species which has been named Lactobacillus gasseri sp. nov. L. gasseri proved to be only distantly related to L. acidophilus as shown by DNA/DNA hybridisation, although it cannot be distinguished from L. acidophilus by classical phenotypical characteristics. However, L. gasseri was found to differ from L. acidophilus by the electrophoretic mobility of its L-LDH and by its cell wall composition.

Using a physiological method for measurement of microbial biomass in soils and production data from three spruce stands in the German IBP study site in Soiling, an attempt was made to relate yearly primary production values to the average quantities of microbial biomass in the organic matter layers (L + F + H) of the forest floors.

The Picea abies stands chosen for study were 39, 87 and 115 years old and contained a yearly average of 5.7, 2.6 and 2.1 mg microbial biomass carbon gdwt organic matter⁻¹. Evaluated on a m² basis, a direct correlation between primary production and microbial biomass in the organic layers was not evident, however, when the production capacity (above ground productivity per unit weight standing crop) was compared to the microbial biomass m⁻², a correlation could be established.

Enrichment cultures inoculated with fragments of the sponge Ircinia spec, under autotrophic culture conditions and with thiosulfate as sole electron donor yielded the predominant development of a small cell Chromatium strain, which is described herein as the new species Chromatium purpuratum. Autotrophically grown cells are 1.2–1.7 μm wide and 3–4 μm long. The cells are motile by means of one single polar flagellum. Intracytoplasmic membranes are present as vesicles as in the other Chromatium species. Multiplication occurs by binary fission. The photopigments are bacteriochlorophyll a and carotenoids of the okenone series. The G + C content of the type strain BN 5500 is 68.9 mole%.

Chromatium purpuratum grows well photoautotrophically with sulfide or thiosulfate as electron donor. Photoheterotrophic growth is possible with various fatty acids serving as electron donor and carbon source. The new species is a marine isolate with an optimal salinity of 5% NaCl. It is compared with other known species of the genus Chromatium.