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.
During a two year screening period, approximately 200 phages active against lactic streptococci have been isolated in a cheese factory from raw milk, cheese whey and starter culture using an indicator set of 24 strains of Streptococcus lactis, 17 strains of S. cremoris and 16 strains of S. lactis subsp. diacetylactis. Electron microscopy of these phages suggests the existence of at least 14 distinct morphological types. The ultrastructural and host range properties of 14 typical phage types are described and discussed.
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.
A novel quantitative microbiological assay is presented. This is based on the finding that the rate of ampicillin-induced lysis of cultures of an auxotrophic E. coli mutant depends on the concentration of the required growth factor the mutant is defective for.
The presence of plasmid DNA was demonstrated for all of 51 investigated strains of Streptococcus lactis, S. lactis subsp. diacetylactis, and S. cremoris. The plasmid patterns of representative strains analysed by agarose gel electrophoresis of the DNA are documented. This pattern does not appear to provide a basis for species differentiating. Lactosenegative derivatives having lost some of their plasmids were obtained by curing with nalidixic acid.
Four French bottled mineral waters (A, B, C and D) were quantitatively and qualitatively microbiologically investigated, i. e. 3 bottles of each charge 1 and 3 weeks after bottling.
A chloridazone-degrading bacterium strain E incubated with trans-cinnamic acid accumulated cis-2.3-dihydro-2.3-dihydroxy-trans-cinnamic acid in the culture medium. A chloridazone-degrading bacterium strain N incubated with trans-cinnamic acid, accumulated 2.3-dihydroxy-trans-cinnamic acid in the culture medium. Each metabolite was isolated in crystalline form and identified by a variety of conventional chemical techniques-Catechol-2.3-dioxygenase prepared from the strain E converted 2.3-dihydroxy-trans-cinnamic acid to the meta cleavage product. Cell extracts converted the yellow ring fission product. The production of fumaric acid could be detected with high performance liquid chromatography and with fumarase.
Using the diaminobenzidine (DAB) reaction catalase activity could be demonstrated cytochemically in cytoplasmic structures of Poria contigua bearing the general ultrastructural features of microbodies. These kidney-shaped compartments were associated with a densely packed coherent membrane system. When H2O2 was replaced by methanol the microbodies were stained indicating that alcohol oxidase generated the H2O2 for the peroxidative conversion of DAB by catalase. Based on these results we assume that catalase and alcohol oxidase are located in microbodies of this fungus as found for methanol-utilizing yeasts.
The “classical” and biochemical characters and the DNA-DNA homology of 37 strains of Lactobacillus acidophilus were determined. Two main homology groups, subdivided into 5 and 2 subgroups, respectively, were established. The subdivision into two main groups was found to correlate with the electrophoretic type of the L-lactic acid dehydrogenase and several features of the cell wall chemistry, whereas no phenotypical characters were found to distinguish the homology subgroups from each other. Therefore the subgroups were not named, although the homology among them was 50% or less, thus justifying their separation into distinct species. At present, only the two main homology groups are considered to constitute named species. The group which contains the type strain of L. acidophilus retains the epithet acidophilus, whereas the other group was recently described as the new species L. gasseri. The implications of the distinct heterogeneity of “L. acidophilus” for intestine bacteriology is discussed.
A selective medium was developed for isolating coagulase-positive and coagulase-negative staphylococci. The selective agents employed were sodium azide, potassium thiocyanate, lithium chloride and glycine. Addition of lithium chloride and glycine is only necessary if high counts of streptococci are expected. All type strains of the various staphylococcal species and other staphylococci tested revealed good growth on this new medium. S. intermedius was the only exception since its recovery was significantly lower than on control medium. However, normal growth of S. intermedius is possible at a lower sodium azide concentration (15–20 mg/litre). Growth of all micrococci and other bacteria such as various bacilli, arthrobacters, lactobacilli, streptococci, Escherichia coli, Enterobacter cloacae and Proteus mirabilis is inhibited: these organisms do not grow at all or at most as pinpoint-sized colonies. Addition of egg yolk or pork plasma to the medium may provide a basis for distinguishing S. aureus from coagulase-negative staphylococci. The new medium is not only useful for the selective isolation of staphylococci but also represents a new routine method für the separation of staphylococci from micrococci. The great specificity of this new medium could be demonstrated in detecting staphylococci in various foods at levels as low as 100/g.
Strain PeH220 of leaf nodule bacteria has been identified as a member of Erwinia herbicola subsp. herbicola by the computer-assisted clustering of 60 phenotypic data, by DNA: rRNA hybridizations with 14C-rRNA from Escherichia coli, Pseudomonas fluorescens and P. acidovorans, and by percent GC determinations. The phenotypical features of the strain have been described.
The numbers of total and actively respiring bacteria were determined in samples of waste-contaminated Baltic sea and lake water. Both parameters were monitored by means of a new simultaneous direct count technique with the aid of a fluorescence microscope. The numbers of total and actively respiring bacteria were consistently higher in polluted samples. The total bacteria numbers were 102 to 104 times greater than plate counts. In addition, the total bacteria numbers showed lower variations from high polluted to low polluted samples than did plate counts. These observations also applied to the actively respiring bacteria. Smaller numbers of these bacteria were always registered for sea water than for lake water. The tendencies described above were better illustrated by the calculated biomass than by the corresponding detected number of bacteria.
The ribosomal 16S RNA of 22 representative organisms of the genera Arthrobacter, Brevibacterium, Cellulomonas, Corynebacterium, Micrococcus and Microbacterium were characterized by oligonucleotide cataloging. Comparative analysis of the data show these genera to be closely related. Genealogically the coryneforms — including the micrococci — can be regarded as members of one broad family, that includes Actinomycetales as well. A separation of this coherent group into distinct families is justified only from a taxonomic point of view.
The effect of the phenylurea herbicides linuron, monolinuron, metobromuron, and the phenoxyalkanoic acid herbicides 2,4-D and 2,4,5-T as well as their corresponding aromatic metabolites 3,4-dichloro-, 4-chloro-, 4-bromoaniline, 2,4-dichloro-, and 2,4,5-trichlorophenol on the agglutination of Rhizobium trifolii was tested with a trifoliin containing seed extract of white clover (Trifolium repens).
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 bacterium capable of utilizing 4-chlorobenzoic acid as its sole carbon source was isolated from soil and tentatively identified as a species of Pseudomonas. The organism is also able to grow on the 4-chloro- and 4-bromo-derivatives of benzoate, phenylacetate, and phenylalanine.
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.
A strain of the genus Aspergillus forming fructification structures with remarkable anomalies in conidiophore, in the vesicle and the conidial head formation is described. The strain shows a combination of characteristics typical of both genera Aspergillus and Penicillium. On this basis, a close phylogenetic relationship between penicilli and aspergilli is postulated.
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 growth factor requirements of ninety-five Gluconobacter strains are examined: 58% of them require pantothenic acid only, 28% require pantothenic acid and nicotinic acid and 6% require pantothenic acid, nicotinic acid and thiamin. Growth factor requirements are strain-specific and are not correlated with the present subdivisions within the genus.
