Proteome of Methanosarcina acetivorans Part II: comparison of protein levels in acetate- and methanol-grown cells

Methanosarcina acetivorans is an archaeon isolated from marine sediments which utilizes a diversity of substrates for growth and methanogenesis. Part I of a two-part investigation has profiled proteins of this microorganism cultured with both methanol and acetate as growth substrates, utilizing two-dimensional gel electrophoresis and MALDI-TOF-TOF mass spectrometry. In this report, Part II, the analyses were extended to identify 34 proteins found to be present in different amounts between methanol- and acetate-grown M. acetivorans. Among these proteins are enzymes which function in pathways for methanogenesis from either acetate or methanol. Several of the 34 proteins were determined to have redundant functions based on annotations of the genomic sequence. Enzymes which function in ATP synthesis and steps common to both methanogenic pathways were elevated in acetate- versus methanol-grown cells, whereas enzymes that have a more general function in protein synthesis were in greater amounts in methanol- compared to acetate-grown cells. Several group I chaperonins were present in greater amounts in methanol- versus acetate-grown cells, whereas lower amounts of several stress related proteins were found in methanol- versus acetate-grown cells. The potential physiological basis for these novel patterns of protein synthesis are discussed.     

Biodegradation of polychlorinated biphenyls by plant cells

The PCB biodegradative ability of plant cells cultivated in vitro in media containing a mixture of PCB congeners, Delor 103, is demonstrated. For experiments we used submerged cultures of Armoracia rusticana, Solanum aviculare, Atropa bella-donna, transformed hairy root or embryogenic cultures of Solanum nigrum. Transformation of PCB was followed by gas chromatography after cultivations of the above-mentioned cultures with Delor 103 (10 mg 100 ml⁻¹). The overall PCB metabolizing capability and also degradation of individual congeners greatly differed from strain to strain. The highest capability to metabolize PCB was assayed with differentiated cultures of Solanum nigrum. Beside the capability of PCB degradation, total peroxidase activity in the medium and the cell extract was also followed. Differentiated or hairy root cultures exhibiting higher degradation abilities of PCB also showed increase of peroxidase activities.     

Abundance of breeding farmland birds on arable and set-aside fields at forest edges

The aim with this study was to investigate whether abundance of farmland birds on fields at forest edges were associated with (I) type of field (young set-aside vs arable fields), (n) the length and structure of the field-forest edge zone, and/or (m) with residual habitats such as habitat islands, ditches, roads etc Twenty-eight farmland bird species (all nesting and/or foraging on open fields) were censused during the breeding season on 48 plots (open fields with adjoining forest edges) in the central parts of Sweden, covering a total area of 595 ha Skylark Alauda arvensis , linnet Carduelis cannabina , whitethroat Sylvia communis and whinchat Saxicola rubetra were found in significantly higher numbers in set-aside-plots than cereal ones However, the most important factor explaining variation in the abundance of most species was the structure of the field-forest ecotone, with the length of shrubby southern deciduous forest edges being the most important factor in 7 of the species Mixed forest edges seemed to be of some importance for the abundance of 3 species, while associations between abundance and length of the other deciduous and coniferous field-forest ecotones only were significant for one species each Skylarks, white wagtails Motaalla alba and whinchats were positively associated to ditches and yellowhammers Emberiza citrinella and linnets were significantly associated to habitat islands The observed preferences for set-asides and shrubby field forest edges are suggested to be results of reduced predation risk and increased food abundance     

Determinants of bryophyte species composition and diversity on the Great Alvar of Öland,Sweden

Factors driving the species richness and distribution of bryophytes are poorly studied and not well understood, particularly in grasslands. We analysed the occurrence of bryophyte species and variation in species richness across 674 plots (0.5?m?×?0.5?m) in alvar vegetation (grassland on limestone pavement with thin or no soil) on Öland (Sweden) in relation to substrate characteristics and chemistry, inundation frequency, grazing pressure and geographical variables. We found 148 taxa, including 11 nationally red-listed ones. Species richness per plot was significantly associated with substrate type, positively associated with pH and grazing intensity, but negatively associated with soil depth. However, richness of species typical of, or restricted to, alvar habitats responded differently to richness of species more common in other habitats. Typical alvar species were favoured by high pH, shallow soil and low phosphate availability, while generalists preferred relatively low pH, higher phosphate availability and organic or mull soil types. Distance from the alvar margin had only weak effects. Concerning the effects on individual species and community composition, inundation frequency and pH were found to have the largest effects, although other factors (substrate type, soil depth, bare soil, bare stone, phosphate availability and grazing pressure) were more important for some individual species, stressing the importance of microsite variability and variability in management for regional species richness. From a conservation perspective, it is concluded that grazing is generally positive whilst factors increasing phosphate availability may disadvantage the typical alvar species, and proximity to the alvar margin is not a major problem.     

The corepressors GPS2 and SMRT control enhancer and silencer remodeling via eRNA transcription during inflammatory activation of macrophages

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