Diel changes in bulk and single-cell bacterial heterotrophic activity in winter surface waters of the northwestern Mediterranean Sea

14 pages, 8 figures, 2 tablesTwo diel cycle studies were conducted to determine the effect of day–night light changes on winter bacterial activity in the coastal Mediterranean (Blanes Bay Microbial Observatory). Bacterial abundances, bacterial heterotrophic activity, and flagellate grazing counts were determined at 4-h intervals during two 3-d periods separated by 2 d. Twice a day, the single-cell activity of major bacterial groups was further analyzed by applying microautoradiography combined with catalyzed reporter deposition-fluorescence in situ hybridization. During the first cycle, all the measured parameters (including the number of active cells in most groups) varied synchronously, with higher values at night and lower during the day. An episode of strong winds between the two studied periods disrupted this periodicity at the onset of the second cycle. The bulk incorporation of 3H-leucine recovered the diel pattern after 2 d, mostly driven by the activity of Gammaproteobacteria. Among the possibilities considered, the observed nighttime increases in the grazing activity of heterotrophic nanoflagellates appeared to partially drive the activity of all bacterial taxa through potential periodic release of dissolved organic matterThis work has been supported by the Spanish Ministry of Science and Innovation (MICINN)through the projects ‘‘Fuentes de Materia Orgánica, Diversidad microbiana y funcionamiento (respiración y Uso del carbono) del ecosistema marino pelágico costero’’ (MODIVUS) (Ciencias y Tecnologías Marinas-CTM2005-04795/MAR) and ‘‘Surface Mixing Modulation of the Exposure to solar Radiation’’ (SUMMER) (Ciencias y Tecnologías Marinas-CTM2008-03309/MAR)Peer reviewe

Presence of 5-hydroxyguaiacyl units as native lignin constituents in plants as seen by Py-GC/MS

Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, 41080-Seville, Spain 2Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain E-mail address: [email protected] (J.C. del Río)The presence of 5-hydroxyguaiacyl moieties in the lignin from several plants has been assessed by Py-GC/MS. Different woody (eucalypt) and nonwoody (flax, hemp, kenaf, jute, sisal and abaca) angiosperms were selected for this study. The pyrolysis of whole fibers released lignin-derived products with p-hydroxyphenyl, guaiacyl and syringyl structures. Indeed, a series of compounds having a 5-hydroxyguaiacyl nuclei, including 3-methoxycatechol, 5-vinyl-3-methoxycatechol and 5-propenyl-3-methoxycatechol, were detected and identified in all samples, although in lower amounts than the normal guaiacyl and syringyl compounds. The analysis of the lignins isolated from the same plants also indicated the presence of 5-hydroxyguaiacyl moieties in the isolated lignins. These compounds are supposed to arise from the pyrolysis of 5-hydroxyguaiacyl moieties, which are supposed to be native constituents of lignin in plants forming benzodioxane substructures.This study has been supported by the Spanish Ministerio de Ciencia y Tecnología (MCyT) and FEDER funds (project AGL2005-01748) and the EU project BIORENEW (NMP2-CT-2006-026456). We thank CELESA S.A. (Tortosa, Spain) for providing the nonwoody plant samples, and ENCE for providing the eucalypt wood sample.Peer reviewe

Vergleichende Untersuchung zu Lebensgewohnheiten und Lebensumfeld von Patienten mit selbstberichteter Multipler Chemikaliensensitivität, Duftstoffallergien oder Polyposis nasi

Background: Environmental factors are discussed as possible causes and/or triggers of multiple chemical sensitivity (MCS), fragrance allergies (FA) and polyposis nasi (PN). Besides other organ systems, a joint effect organ of MCS, FA and PN is the respiratory tract. Therefore, aim of the present study was to characterize and compare living conditions and living factors of persons with self-reported MCS (sMCS), FA or PN.Material and Methods: Dependence of variable distribution of a standardized questionnaire of living conditions and living factors was compared between the three patient groups using Pearson’s X²-test. In case of a significant value, pairwise comparisons were done with Fisher’s exact test. Metric variables were compared with Kruskal-Wallis- and Mann-Whitney-U-test. Significant results in Fisher’s exact test or Mann-Whitney-U-test were Bonferroni adjusted.Results: The sMCS group consisted of 14 men and 45 women, the FA group of 19 men and 25 women and the PN group of 42 men and 27 women. Questionnaire variables with a significantly different distribution between the three patient groups were: Chemicals as suspected cause of health disturbances (p=0.000), use of perfume (p=0.000), present amalgam fillings (p=0.000), alcohol consumption (p=0.007), age of residential building (p=0.03), use of humidifier at home (p=0.014), mould exposure at home (p=0.035), age of furniture at home (p=0.001), indoor plants at home (p=0.029), use of disinfections (p=0.006) and insecticides (p=0.004), daily time stayed at home (p=0.032), different kinds of annoyance at home (p=0.000), sense of wellbeing at home (p=0.000) as well as exposures to photocopy machines (p=0.000) and odors (p=0.000) at workplace. In most cases, the questionnaire variables investigated were significantly different distributed between the sMCS group and the FA-/PN group.Conclusions: The different distribution of the questionnaire variables investigated between the sMCS-, FA- and PN group regarded mainly environmental factors with odorous components. Reactions to these factors were lesser pronounced in the FA group than in the sMCS group. In the PN group no association between PN and the living conditions and living factors investigated were observed