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Taxonomic Affiliation (taxonomic + affiliation)
Selected AbstractsA new species of Allium subgen.FEDDES REPERTORIUM, Issue 3-4 2005Melanocrommyum sect. Allium hooshidaryaeMashayekhi, Zarre & R. M. Fritsch sp. nova (sect. Compactoprason) from Kordestan is newly described. Its taxonomic affiliation and relationship is discussed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Eine neue Art von Allium Untergattung Melanocrommyum Sekt. Compactoprason (Alliaceae) aus dem Iran Allium hooshidaryaeMashayekhi, Zarre & R. M. Fritsch sp. nova (sect. Compactoprason) aus der Provinz Kordestan im Iran wird neu beschrieben. Die taxonomische Verwandschaft zu den nächsten Arten wird diskutiert. [source] Influences of species, latitudes and methodologies on estimates of phenological response to global warmingGLOBAL CHANGE BIOLOGY, Issue 9 2007CAMILLE PARMESANArticle first published online: 14 AUG 200 Abstract New analyses are presented addressing the global impacts of recent climate change on phenology of plant and animal species. A meta-analysis spanning 203 species was conducted on published datasets from the northern hemisphere. Phenological response was examined with respect to two factors: distribution of species across latitudes and taxonomic affiliation or functional grouping of target species. Amphibians had a significantly stronger shift toward earlier breeding than all other taxonomic/functional groups, advancing more than twice as fast as trees, birds and butterflies. In turn, butterfly emergence or migratory arrival showed three times stronger advancement than the first flowering of herbs, perhaps portending increasing asynchrony in insect,plant interactions. Response was significantly stronger at higher latitudes where warming has been stronger, but latitude explained < 4% of the variation. Despite expectation, latitude was not yet an important predictor of climate change impacts on phenology. The only two previously published estimates of the magnitude of global response are quite different: 2.3 and 5.1 days decade,1 advancement. The scientific community has assumed this difference to be real and has attempted to explain it in terms of biologically relevant phenomena: specifically, differences in distribution of data across latitudes, taxa or time periods. Here, these and other possibilities are explored. All analyses indicate that the difference in estimated response is primarily due to differences between the studies in criteria for incorporating data. It is a clear and automatic consequence of the exclusion by one study of data on ,stable' (nonresponsive) species. Once this is accounted for, the two studies support each other, generating similar conclusions despite analyzing substantially nonoverlapping datasets. Analyses here on a new expanded dataset estimate an overall spring advancement across the northern hemisphere of 2.8 days decade,1. This is the first quantitative analysis showing that data-sampling methodologies significantly impact global (synthetic) estimates of magnitude of global warming response. [source] Sucrose phosphorylase of the rumen bacterium Pseudobutyrivibrio ruminis strain AJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2009A. Kasperowicz Abstract Aims:, To verify the taxonomic affiliation of bacterium Butyrivibrio fibrisolvens strain A from our collection and to characterize its enzyme(s) responsible for digestion of sucrose. Methods and Results:, Comparison of the 16S rRNA gene of the bacterium with GenBank showed over 99% sequence identity to the species Pseudobutyrivibrio ruminis. Molecular filtration, native electrophoresis on polyacrylamide gel, zymography and thin layer chromatography were used to identify and characterize the relevant enzyme. An intracellular sucrose phosphorylase with an approximate molecular mass of 52 kDa exhibiting maximum activity at pH 6·0 and temperature 45°C was identified. The enzyme was of inducible character and catalysed the reversible conversion of sucrose to fructose and glucose-1-P. The reaction required inorganic phosphate. The Km for glucose-1-P formation and fructose release were 3·88 × 10,3 and 5·56 × 10,3 mol l,1 sucrose, respectively , while the Vmax of the reactions were ,0·579 and 0·9 ,mol mg protein,1 min,1. The enzyme also released free glucose from glucose phosphate. Conclusion:,Pseudobutyrivibrio ruminis strain A utilized sucrose by phosphorolytic cleavage. Significance and Impact of the Study:, Bacterium P. ruminis strain A probably participates in the transfer of energy from dietetary sucrose to the host animal. [source] Purification and molecular characterization of subtilisin-like alkaline protease BPP-A from Bacillus pumilus strain MS-1LETTERS IN APPLIED MICROBIOLOGY, Issue 3 2006T. Miyaji Abstract Aims:, The present study was conducted by screening zein-degrading bacteria in an attempt to obtain zein-degrading protease. Methods and Results:, Soil bacteria were screened by formation of a clear zone on zein plates. Characterization of a zein-degrading bacterium indicated a taxonomic affiliation to Bacillus pumilus, and was named MS-1 strain. The strain produced two different types of extracellular proteases, BPP-A and BPP-B. In this study, we purified and characterized BPP-A because it exhibited a higher ability to hydrolyze zein than BPP-B. When casein was used as the substrate, the optimal pH for BPP-A was 11·0. In BPP-A, zein was better substrate than casein at pH 13·0, whereas casein was better one than zein at pH 11·0. The bppA gene encoded a 383-amino acid pre-pro form of BPP-A, and mature BPP-A contained 275 amino acid residues. It was concluded that BPP-A belonged to the subtilisin family. Conclusion:, A zein-degrading bacterium assigned to B. pumilus produced two different types of extracellular proteases, BPP-A and BPP-B. BPP-A exhibited an ability to hydrolyze zein in an extreme alkaline condition. Significance and Impact of the Study:, This is a first report on screening for zein-degrading micro-organisms. The subtilisin-like protease BPP-A is possible to utilize as an industrial enzyme for the production of zein hydrolysates. [source] Refugia, differentiation and postglacial migration in arctic-alpine Eurasia, exemplified by the mountain avens (Dryas octopetala L.)MOLECULAR ECOLOGY, Issue 7 2006INGER SKREDE Abstract Many arctic-alpine organisms have vast present-day ranges across Eurasia, but their history of refugial isolation, differentiation and postglacial expansion is poorly understood. The mountain avens, Dryas octopetala sensu lato, is a long-lived, wind-dispersed, diploid shrub forming one of the most important components of Eurasian tundras and heaths in terms of biomass. We address differentiation and migration history of the species with emphasis on the western and northern Eurasian parts of its distribution area, also including some East Greenlandic and North American populations (partly referred to as the closely related D. integrifolia M. Vahl). We analysed 459 plants from 52 populations for 155 amplified fragment length polymorphisms (AFLP) markers. The Eurasian plants were separated into two main groups, probably reflecting isolation and expansion from two major glacial refugia, situated south and east of the North European ice sheets, respectively. Virtually all of northwestern Europe as well as East Greenland have been colonized by the Southern lineage, whereas northwest Russia, the Tatra Mountains and the arctic archipelago of Svalbard have been colonized by the Eastern lineage. The data indicate a contact zone between the two lineages in northern Scandinavia and possibly in the Tatra Mountains. The two single populations analysed from the Caucasus and Altai Mountains were most closely related to the Eastern lineage but were strongly divergent from the remaining eastern populations, suggesting survival in separate refugia at least during the last glaciation. The North American populations grouped with those from East Greenland, irrespective of their taxonomic affiliation, but this may be caused by independent hybridization with D. integrifolia and therefore not reflect the true relationship between populations from these areas. [source] | ||||||||||