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Minor Portion (minor + portion)
Selected AbstractsHigh bacterial diversity of a waste gas-degrading community in an industrial biofilter as shown by a 16S rDNA clone libraryENVIRONMENTAL MICROBIOLOGY, Issue 11 2002Udo Friedrich Summary The bacterial diversity of an industrial biofilter used for waste gas abatement in an animal-rendering plant was investigated. A 16S rDNA clone library was generated and 444 clones were screened using computer-aided amplified ribosomal DNA restriction analysis (ARDRA). Of the screened clones, 60.8% showed unique ARDRA patterns and the remaining 174 clones were clustered into 65 groups. Almost full-length 16S rDNA sequences of 106 clones were determined and 90.5% of the clones were affiliated with the two phyla Proteobacteria and Bacteroidetes. Alpha -, Beta -, and Gammaproteobacteria accounted for 22.1, 17.6 and 18.6% respectively. Minor portions were affiliated with the Actinobacteria (2.0%), Firmicutes and Verrucomicrobia (both 1.0%), and the Deltaproteobacteria and Thermomicrobia (each 0.5%). Only six out of the 106 16S rDNA sequences exhibited similarities of more than 97% to classified bacterial species indicating that a substantial fraction of the clone sequences were derived from unknown taxa. It was also evaluated whether a database containing 281 computer-simulated bacterial rDNA fragment patterns generated from published reference sequences can be used for identification purposes. The data analysis demonstrated that this was possible only for a small number of clones, which were closely related to described bacterial strains. Rarefaction analysis of ARDRA clusters demonstrated that the 444 clones screened are insufficient to describe the entire diversity of the clone library. [source] Naturally occurring egg parasitoids of the genus Trichogramma (Hymenoptera: Trichogrammatidae) in a pomegranate orchard in TunisiaENTOMOLOGICAL SCIENCE, Issue 1 2010Ines KSENTINI Abstract Four Trichogramma species were found in a pomegranate orchard in Gabès, an arid region of Tunisia, from parasitized eggs of Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae), an economically important insect pest. Identification based on assessment of male genitalia and internal transcribed spacer 2 (ITS2) sequences showed that they were T. bourarachae Pintureau and Babault, 1988, T. oleae Voegelé and Pointel, 1979, T. cacoeciae Marchal, 1927 and T. evanescens Westwood, 1833. Trichogramma evanescens is reported for the first time in Tunisia. Trichogramma cacoeciae was the largely dominant species in the analyzed samples, whereas T. bourarachae was present in a minor portion of 1.38%. The implications of these results for attempts at controlling E. ceratoniae are discussed. [source] Structural evidence for a constant c11 ring stoichiometry in the sodium F-ATP synthaseFEBS JOURNAL, Issue 21 2005Thomas Meier The Na+ -dependent F-ATP synthases of Ilyobacter tartaricus and Propionigenium modestum contain membrane-embedded ring-shaped c subunit assemblies with a stoichiometry of 11. Subunit c from either organism was overexpressed in Escherichia coli using a plasmid containing the corresponding gene, extracted from the membrane using detergent and then purified. Subsequent analyses by SDS/PAGE revealed that only a minor portion of the c subunits had assembled into stable rings, while the majority migrated as monomers. The population of rings consisted mainly of c11, but more slowly migrating assemblies were also found, which might reflect other c ring stoichiometries. We show that they consisted of higher aggregates of homogeneous c11 rings and/or assemblies of c11 rings and single c monomers. Atomic force microscopy topographs of c rings reconstituted into lipid bilayers showed that the c ring assemblies had identical diameters and that stoichiometries throughout all rings resolved at high resolution. This finding did not depend on whether the rings were assembled into crystalline or densely packed assemblies. Most of these rings represented completely assembled undecameric complexes. Occasionally, rings lacking a few subunits or hosting additional subunits in their cavity were observed. The latter rings may represent the aggregates between c11 and c1, as observed by SDS/PAGE. Our results are congruent with a stable c11 ring stoichiometry that seems to not be influenced by the expression level of subunit c in the bacteria. [source] Occurrence of Histamine-Forming Bacteria in Albacore and Histamine Accumulation in Muscle at Ambient TemperatureJOURNAL OF FOOD SCIENCE, Issue 4 2002S.H. Kim ABSTRACT Distribution of histamine-producing bacteria in fresh albacore and their proliferation in muscle during storage at 25 °C were monitored. Histamine formers constituted a minor portion of the bacterial flora in albacore. Only weak histamine formers were detected in the gill and skin of fresh fish after enrichment. Histamine formers were isolated from the muscles when APC reached >107 CFU/g during storage. Hafnia alvei was most prevalent in both fresh and temperature-abused fish. The most prolific histamine former, Morganella morganii, was rarely isolated even from spoiled muscles. The prevalence of weak histamine formers resulted in low levels of histamine accumulation in muscle, 67.1 mg/100 g, for 6 d of storage. [source] Searching for the source regions of martian meteorites using MGS TES: Integrating martian meteorites into the global distribution of igneous materials on MarsMETEORITICS & PLANETARY SCIENCE, Issue 6 2003Victoria E. HAMILTON We deconvolved the TES data set using laboratory spectra of 6 martian meteorites (Los Angeles, Zagami, ALH A77005, Nakhla, ALH 84001, and Chassigny) as end members, along with atmospheric and surface spectra previously derived from TES data. Global maps (16 pixels/degree) of the distribution of each meteorite end member show that meteorite-like compositions are not present at or above TES detectability limits over most of the planet's dust-free regions. However, we have confidently identified local-scale (100s-1000s km2) concentrations of olivine- and orthopyroxene-bearing materials similar to ALH A77005, Chassigny, and ALH 84001 in Nili Fossae, in and near Ganges Chasma, in the Argyre and Hellas basin rims, and in Eos Chasma. Nakhla-like materials are identified near the detection limit throughout the eastern Valles Marineris region and portions of Syrtis Major. Basaltic shergottites were not detected in any spatially coherent areas at the scale of this study. Martian meteorite-like lithologies represent only a minor portion of the dust-free surface and, thus, are not representative of the bulk composition of the ancient crust. Meteorite-like spectral signatures identified above TES detectability limits in more spatially restricted areas (
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