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

The storage of 140 strains of yeasts in liquid nitrogen at −196°C has been investigated with respect to composition of the freezing medium and survival of cells. The best results were obtained with a freezing mixture containing dimethylsulfoxide, skimmed milk and Ficoll 400, in which 74% of the strains examined showed survival rates of more than 60%. It is not yet possible to give a generally applicable procedure for optimal survival rates of yeasts under liquid nitrogen, since the various strains react very differently to the freezing conditions.

The API ZYM system has been evaluated for use in identification of C. equi. One hundred strains were tested, and compared with representatives of coryneform and related taxa. The system is rapid and reliable and gives a pattern of reactions of C. equi which is consistent and characteristic.

Eight strains of homofermentative lactobacilli from the dental plaque of primates had similar and unusual SDS-gel electrophoresis patterns of polypeptides. Two other strains from the intestines of non-primates were also recognised by their polypeptide patterns. The physiological reactions of these strains resembled Lactobacillus acidophilus and L. ruminis. The peptidoglycan type was L-Lys-D-Asp, but the DNA contained 41.3–44.4 mol% G + C and the acid formed was L (+) lactate. A new species, Lactobacillus animalis, is proposed for these strains.

The name Corynebacterium mycetoides (Castellani) Ortali and Capocaccia 1956 was omitted from the Approved Lists of Bacterial Names and therefore lost standing in bacterial nomenclature. The name Corynebacterium mycetoides is here revived for the same organism to which the name was originally applied. The type strain is NCTC 9864.

Menaquinones (vitamin K₂) were the only isoprenoid quinones found in the Actinomycetes tested. Thermomonospora strains belonging to the species T. alba, T. curvata and T. fusca contained very complex mixtures of menaquinones with nine, ten and eleven isoprene units. Hexa- and octahydrogenated menaquinones with ten isoprene units constituted the major components in T. alba, whereas, octahydrogenated menaquinones with ten isoprene units predominated in T. curvata and T. fusca. Substantial amounts of hitherto undescribed hexa-, octa-, and decahydrogenated menaquinones with eleven isoprene units were also present in the three species.

The representative of the taxon Thermomonospora (Actinobifida) chromogena examined differed in possessing major amounts of tetrahydrogenated menaquinones with only nine isoprene units; a pattern also found in Saccharomonospora viridis, Actinomadura flexuosa and Micromonospora halophytica subsp. halophytica. The chemotaxonomic data and supporting results of numerical taxonomic studies suggest that Actinobifida chromogena may have been wrongly classified in the genus Thermomonospora.

An anaerobic, chemolithotrophic, acetogenic bacterium has been isolated from the sewage digestor in Göttingen. The Gram positive cells were rod shaped and showed subterminal flagellation. The organism grew chemolithotrophically with H₂ and CO₂ forming acetic acid as the sole end product. The optimal temperature for growth was 30 °C and the optimal pH for chemolithotrophic growth was about 7.6. The doubling time under these conditions was less than 10 h. D-fructose or D,L-lactate served as organic substrates. The DNA contained 43 mol% guanine plus cytosine.

As compared to Acetobacterium woodii the substrate spectrum of the new isolate was more restricted, e.g. glucose was not fermented. DNA-DNA-hybridization experiments showed only a 34% homology of the DNAs of A. woodii and the new isolate. Therefore, the new isolate is described as a new species, Acetobacterium wieringae, in honour of K. T. Wieringa who first isolated and described Clostridium aceticum.

The resistance of 286 strains of E. coli isolated from surface waters, ground water and breeding effluents, to five antibiotics and three heavy metals, was compared with that of 104 E. coli strains of human origin.

The highest percentage of resistance among the environmental isolates was found in the strains obtained from river water. The percentage of resistance to different antibiotics was variable and found to be highest with respect to ampicillin, streptomycin and tetracycline.

Multiresistance phenomena were observed primarily with the isolates from surface waters and those of human origin.

Correlation analysis revealed that the resistance patterns of E. coli isolates from water environments are related, but only the antibiotic resistance pattern of river isolates was correlated with that of the strains of human origin. No correlation could be detected with respect to the antibiotic resistance patterns of environmental strains and strains isolated from breeding effluents.

Antibiotic and metal resistance were transferred to the recipient E. coli CSH 26 Nal strain by eleven of twelve strains tested: the transfer took place with the transconjugantdonor ratio varying from 10⁻¹ to 10⁻⁴, the ratio being higher for the metals than for the antibiotics.

Mucor mucedo showed maximum growth and lipase production at 30 °C after 3 days at pH 7.0. Aeration stimulated lipase yield by 40%. No significant difference in growth and lipase production was observed with different carbohydrates. Among the nitrogen sources tested, peptone at 2% lead to maximum lipase yield. The addition of Tributyrin to the growth medium increased lipase production by 66% while the addition of other lipids caused a reduction.

The union of the genera Cellulomonas and Oerskovia is indicated by the close natural relationship and the high similarity in physiological, biochemical and metabolic properties found between species of the two genera. An emended genus Cellulomonas is proposed for the two genera united. Oerskovia turbata is reclassified as Cellulomonas turbata comb. nov., while Oerskovia xanthineolytica, together with Nocardia cellulans, Brevibacterium fermentans and Brevibacterium liticum are considered as strains of Cellulomonas cartae. An emended description of the latter is given.

The nutritional pattern of five groups of filamentous bacteria isolated from bulking sludge is described. Four groups, two with gliding motility, comprised Gram-negative, rod-shaped, sheathed bacteria. The Gram-positive, coccoid bacteria of group V formed sheathless filaments. The metabolism of carbohydrates, lipids, organic acids and proteins in groups I-V has been examined.

Group I isolates degraded polymeric substrates, while the others, especially group IV, preferred monomeric carbon sources.