Screening of thermostable leucine and alanine dehydrogenases in thermophilicBacillus strains

Summary Screening of leucine and alanine dehydrogenases in thermophilicBacillus strains was carried out to develop their utilization for industrial and analytical catalysts. Out of the 28 thermophilic strains tested, four strains,Bacillus sp. DSM 405, 730 and 1521, andB. sphaericus DSM 462, abundantly produce both the enzymes. Both the enzyme activities in these thermophiles are enhanced by addition of the substrates to a polypeptone medium.     

Probleme der Flechten-Chemotaxonomie — Stoffkombinationen und ihre taxonomische Wertung

Die Kombination (Koppelung) der Stoffe im Chemosyndrom kann gegenseitig oder einseitig obligat oder auch fakultativ sein. Dabei ist die Stellung der beteiligten eng verwandten Produkte im Rahmen der Biosynthese von Fall zu Fall verschieden. — Dem Chemotaxonomen kann die Berücksichrigung dieser Aspekte zumindest tendenziell als Anhaltspunkt dienen. Bei Vorkommen der Komponenten in verschiedenen Verwandtschaftskreisen wird man ein Chemosyndrom - also eine Kornbination biogenetisch eng verwandter Verbindungen - urn so eher als ein einziges Merkmal betrachten können, je seltener die Kombination aufgelöst ist. Zweifellos stellen der solitare Stoff als Einzelmerkmal und die ohne Ausnahme auftretende (obligate) Kombination als Einzelmerkmal nur Extreme einer gleitenden Reihe dar. Herrn Prof. Dr. E. KLUG (Berlin) danke ich für die Durchsicht des Manuskripts und für werrvolle Diskussion, Herrn H. LÜNSER für die sorgfältige Ausführung der Zeichnungen, Frau I. EGGERT, Frau C. MÜLLER und Frau 1. POHL für die Hilfen bei der Vorbereitung des Manuskripts. Herrn Dr. M. SEAWARD (Bradford) bin ich für Beratung und Diskussion in Zusammenhang mit der Form der englischen Zusammenfassung sehr zu Dank verpflichter,     

Bufonid nucleocytoplasmic hybrids arrested at the early gastrula stage lack a fibronectin-containing fibrillar extracellular matrix

Summary Most hybrids betweenBufo bufo andB. calamita obtained by nuclear transplantation become arrested at the early gastrula stage. In both parental controls and the hybrid embryos, the presence and distribution of extracellular matrix was analysed with fluorescent wheat germ agglutinin and by immunolabelling with antibodies directed against fibronectin. InB. bufo andB. calamita gastrulae and in the few hybrids that complete gastrulation, the inner surface of the blastocoel roof is covered by a fibronectin-rich fibrillar matrix. In nucleocytoplasmic hybrids whose development was arrested at the gastrula stage, the fibronectin-containing extracellular matrix was either totally absent or poorly developed and disorganized.     

Animal community structure as a function of stream size

The species-area relationship of the island biogeography theory was calculated for macroinvertebrates in 22 coastal, adjacent streams. A z-value of 0.19 was obtained. The low z-value was probably a consequence of the short distances between streams as well as high dispersal rates. In addition, a cluster analysis based on the dissimilarity of species assemblages showed that stream size was of prime importance in categorizing the streams. To a smaller extent water quality affected the community structure in the streams.     

Spore production ofPenicillium roqueforti in fermentors filled with buckwheat seeds: batch and semi-continuous cultivation

Summary The behaviour of a drum fermentor and a column fermentor during the sporulation ofPenicillium roqueforti on buckwheat seeds is presented. The main problem encountered during the course of a cultivation is the free water released (about 0.1 ml/g dry matter) which must be removed from the medium. The rotation of the drum fermentor may disturb the growth and the sporulation. The column fermentor thus represents the best way to perform batch cultivation of the fungus: 10⁹ external spores/g dry matter are obtained.Semi-continous cultivation, with sequential emptying and filling, is performed in 1-liter bottles. This kind of cultivation may give a maximal average productivity close to 9.2·10⁶ external spores/g dry matter per hour. A drum fermentor, rotading only when emptying and filling, could represent an alternative to perform this kind of cultivation.     

Neurospora tyrosinase: structural,spectroscopic and catalytic properties

Summary Tyrosinase is a copper containing monooxygenase catalyzing the formation of melanin pigments and other polyphenolic compounds from various phenols. This review deals with the recent progress on the molecular structure of the enzyme from Neurospora crassa and the unique features of the binuclear active site copper complex involved in the activation of molecular oxygen and the binding of substrates. The results of the spectroscopic properties of Neurospora tyrosinase will also be discussed in the light of the structural similarity of the copper complex in the oxygen binding hemocyanins.