Schriftenschau

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Production of cellulase and protein from barley straw by Trichoderma viride

The cellulase production by two strains of the cellulolytic fungus Trichoderma viride was examined. The fungi were grown on different preparations of barley straw pretreated with NaOH under high pressure. The production of cellulases and microbial protein by the better strain (QM 9123) was investigated in an aerated 5-liter fermenter under varying stirring rates (200-350 rpm) and straw concentrations (1–2%). The pH was kept between 3.5 and 4.5. The growth of the fungus was followed by measuring the quantity of CO₂ produced and the cell protein. After 2–6 days growth ceased, the lag phases lasting 0–2 days, increasing with increasing straw concentrations. The maximum enzyme yields were reached after 4–10 days. The protein content of the product was 21–26% and up to 70% of the straw was utilized. The yield constants were calculated to be 0.40–0.56; of the same order as those which can be obtained by growing the fungus on glucose.     

Postembedding immunogold histochemistry for the localization of laminin and its E4 and P1 fragments in mouse kidney embedded in LR-White and LR-Gold

Summary A method is presented which permits the ultrastructural localization of laminin and its E4 and P1 subunits in the renal cortex of the mouse embedded in LR-White or LR-Gold. It was performed with postembedding immunogold histochemistry using polyclonal antibodies against either the entire laminin molecular or the E4 fragment or with a monoclonal antibody against the P1 fragment. Localization of laminin was achieved in LR-White and in LR-Gold embedded kidney. Using polyclonal antibodies against the entire laminin molecule, laminin could be localized with direct as well as with indirect immunogold histochemistry with a gold labelled IgG as secondary antibody. In contrast, immunostaining for the E4 or the P1 fragments was possible only with antibodibodies directly labelled with gold.     

Analysis of bacterial communities in a municipal duck pond during a phytoplankton bloom and isolation of Anatilimnocola aggregata gen. nov., sp. nov., Lacipirellula limnantheis sp. nov. and Urbifossiella limnaea gen. nov., sp. nov. belonging to the phylum Planctomycetes

Waterbodies such as lakes and ponds are fragile environments affected by human influences. Suitable conditions can result in massive growth of phototrophs, commonly referred to as phytoplankton blooms. Such events benefit heterotrophic bacteria able to use compounds secreted by phototrophs or their biomass as major nutrient source. One example of such bacteria are Planctomycetes, which are abundant on the surfaces of marine macroscopic phototrophs; however, less data are available on their ecological roles in limnic environments. In this study, we followed a cultivation-independent deep sequencing approach to study the bacterial community composition during a cyanobacterial bloom event in a municipal duck pond. In addition to cyanobacteria, which caused the bloom event, members of the phylum Planctomycetes were significantly enriched in the cyanobacteria-attached fraction compared to the free-living fraction. Separate datasets based on isolated DNA and RNA point towards considerable differences in the abundance and activity of planctomycetal families, indicating different activity peaks of these families during the cyanobacterial bloom. Motivated by the finding that the sampling location harbours untapped bacterial diversity, we included a complementary cultivation-dependent approach and isolated and characterized three novel limnic strains belonging to the phylum Planctomycetes.     

Oxidation-Reduction Sequence for the Synthesis of Peracylated Fluorodeoxy Pentofuranosides

Abstract

Oxidation of 1a with DMSO-acetic or trifluoroacetic anhydride led to the formation of a mixture of epimeric gem-diols 2 and 3 in the ratios of ?3:1 and ?7:1, respectively. Reduction of this mixture with NaBH₄ followed by benzoylation and chromatography afforded 4a and 5a.     

Kurze Mitteilungen

Ohne Zusammenfassung     

Das Lernprogramm in der Gesangsausbildung der Strohwitwc Tetraenura fischeri Reichenow*)

Die ökologischen Ansprüche von Trithyreus Sturmi Kraus, einer kleinen kolumbianischen Art von Geißelskorpionen, werden kurz charakterisiert. Innerhalb des Verhaltens werden Fortbewegung, Beutefang, verschiedene Putzbewegungen, Graben und Einzelheiten von Balz und Paarung beschrieben. Während der Balz zeigt das ♂ vor dem ♀, aber ohne direkten Kontakt mit ihm, verschiedene Arten rhythmischer Bewegungen, die das ♀ schließlich mit Zulaufen auf das ♂ beantwortet. Beim anschließenden Paarungsmarsch hängt sich das ♀ mit seinen Chelizeren in paarigen Strukturen des verdickten Flagellum des ♂ fest. Auf diese Weise kann es vom ♂ über die nach einigen Viertelstunden bis Stunden abgesetzte Spermatophore gezogen werden. Es handelt sich um indirekte Spermatophorenübertragung mit hoch differenzierter Spermatophore (Stiel, flügelartige Teile, paarige Samenpakete mit schlauchartigen Innenstrukturen) und spezialisierten Verhaltensweisen zur Sicherung der Übertragung. Die Beobachtungen werden im Hinblick auf die Verhältnisse bei anderen Pedipalpengruppen diskutiert.