Effect of pH and butyrate concentration on the production of acetone and butanol by Clostridium acetobutylicum grown in continuous culture

Summary When Clostridium acetobutylicum was grown in continuous culture under glucose limitation at neutral pH and varying dilution rates the only fermentation products formed were acetate, butyrate, carbon dioxide and molecular hydrogen. The Y _glucose ^max and (Y _ATP ^max ) _gluc ^exp values were 48.3 and 23.8 dry weight/mol, respectively. Acetone and butanol were produced when the pH was decreased below 5.0 (optimum at pH 4.3). The addition of butyric acid (20 to 80 mM) to the medium with a pH of 4.3 resulted in a shift of the fermentation from acid, to solvent formation.A preliminary report of part of this work was presented at a symposium Trends in the Biology of Fermentations for Fuels and Chemicals held December 7–11, 1980, at Brookhaven National Laboratory, Upton, New York; Gottschalk and Bahl 1981     

Isolation and identification of spirorenone metabolites from the monkey (Macaca fascicularis)

The plasma level of spirorenone was determined 3 h after 1, 8, 22 and 46 daily oral administrations of 20 mg/kg to two female and two male monkeys ($\text{Macaca fascicularis}$). A fifth animal, female, was treated with eight daily doses of tritium-labelled drug and was completely bled from the carotid vein 4 h after the last administration in order to isolate and identify plasma metabolites.After repeated daily doses of spirorenone the mean plasma level of unchanged drug was 711 ± 213 ng/ml. In the plasma of the fifth animal four radioactively labelled compounds could be detected after extraction and subsequent HPLC separation. Mass spectrometric identification of three of the substances indicated 1,2-dihydrospirorenone, hydroxy-1,2-dihydrospirorenone and the unchanged drug itself.     

Phytochrome control of plastid mRNA in mustard (Sinapis alba L.)

The steady-state levels of plastid RNA sequences in dark-grown and light-grown mustard (Sinapis alba L.) seedlings have been compared. Total cellular RNAs were labeled in vitro with ³²P and hybridized to separated restriction fragments of plastid DNA. Cloned DNA fragments which encode the large subunit (LS) of ribulose-1,5-bisphosphate carboxylase [3-phospho-D-glycerate carboxylase (dimerizing), EC 4.1.1.39] and a 35,000 plastid polypeptide were used as probes to assess the levels of these two plastid mRNAs. The 1.22-kilobase-pair mRNA for the 35,000 polypeptide is almost undetectable in dark-grown seedlings, but is a major plastid mRNA in light-grown seedlings. The hybridization analysis of RNA from seedlings which were irradiated with red and far-red light indicates that the level of this mRNA, but not of LS mRNA, is controlled by phytochrome.Abbreviations LS large subunit - RuBP ribulose-1,5-bisphosphate - ptDNA plastid DNA     

Hemoglobins,XLVIIII

Summary Hagfish hemoglobin has three main components, one of which is Hb III. It is monomeric and consists of 148 amino acid residues (M = 17 350). Its complete primary structure, previously published, is discussed here. The proximal amino acid (F8) of the heme linkage is histidine as always in the hemoglobins, but the regularly expected distal histidine E7 is substituted by glutamine. This substitution, leading to a new kind of heme linkage, has hitherto only been demonstrated in opossum hemoglobin. It is suggested that E7, Gln, is directed out of the heme pocket, and that the adjacent Ell, Ile, is directed toward the inside of the pocket, giving the distal heme contact instead of histidine.Myxine Hb III has an additional tail of 9 amino acid residues at its N-terminal end, as has the hemoglobin ofLampetra fluviatilis. The genetic codes ofMyxine andLampetra hemoglobins show 117 differences, in spite of many morphological resemblances between hagfish and lamprey. Their primary hemoglobin structures show differences substantial enough to bo compatible with the divergence of the two families some 400–500 million years ago.     

Studies on the evolutionary relationships between hemoglobins inChironomus pallidivittatus andC. Tentans

Summary The monomeric hemoglobins ofChironomus tentans andC. pallidivittatus have been isolated and separated into their respective components by gel chromatography on Sephadex G-75 and ion-exchange chromatography on DEAE-Sephacel. The amino acid compositions of the purified components are given. The sequence of the 30 N-terminal amino acid residues of one of the monomeric components (Hb I fromC. pallidivittatus) was determined and found to be identical in almost all of its parts with the monomeric hemoglobins ofC. thummi (CTT III and CTT IV).Antibodies against the monomeric hemoglobins Hb I and Hb IIc and the dimeric fraction were highly specific and no cross reaction between dimeric and monomeric hemoglobins could be demonstrated. The antibodies against the monomers crossreact with the monomeric hemoglobins CTT III and CTT IV ofC. thummi. Taken together with genetic data, the immunological results indicate that divergence of monomeric from dimeric forms was an early event in the evolution of the various hemoglobins inChironomus.     

Versuche zum angenommenen Kontrastverlust im Gesang der Blaumeise (Parus caeruleus) auf Teneriffa

Zusammenfassung Der Gesang von Blaumeisen-Populationen in Mitteleuropa, Spanien, Marokko und auf Teneriffa wurde miteinander verglichen (Abb. 1). In Süddeutschland und auf Teneriffa wurden Klang-Attrappen-Versuche durchgeführt.1. Der Blaumeisen-Gesang ist in Marokko und auf Teneriffa sehr ähnlich. Er unterscheidet sich vom Blaumeisengesang in Europa (Mitteleuropa und Spanien) in folgenden Eigenschaften (2.–4.):2. Ihm fehlen phrasierte Strophen (Abb. 2 a–c, e, 3, 4 a, b, f, g), also Strophen, in denen dasselbe Element mindestens viermal nacheinander wiederholt wird.3. Er enthält mehr verschiedene Elemente (Abb. 5, 7).4. Die interindividuelle Variation ist größer (Abb. 6, 7).5. Die Unterschiede zwischen dem Blaumeisen-Gesang in Europa und auf Teneriffa lassen sich nicht mit der Kontrast-Betonungs- und der Kontrast-Verlust-Hypothese nachLack &Southern (1949) undMarler (1960) erklären. Die Lernentzugs-Hypothese erklärt sie besser.6. Die Blaumeisen von Teneriffa und Marokko sind sehr nahe miteinander verwandt, aber vermutlich sind sie von den europäischen Blaumeisen artlich nicht getrennt.

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The song of the Blue Tit (Parus caeruleus) on Tenerife: Experiments on a presumed loss of contrast

Summary Songs of Blue Tit populations from Central Europe, Spain, Morocco and Tenerife (fig. 1) were compared. Playback experiments were made in South Germany and on Tenerife.1. Blue Tit songs from Morocco and Tenerife are very similar. They differ from songs of Blue Tits in Europe (Central Europe and Spain) in the following characteristics (2–4):2. Lack of phrased songs (fig. 2 a–c, e, 3, 4 a, b, f, g), i. e. songs with the same notes repeated successively at least four times.3. A greater number of different types of notes (fig. 5, 7).4. Greater interindividual variation (fig. 6, 7).5. Differences between Blue Tit song from Europe and from Tenerife cannot be explained by the hypothesis of contrast reinforcement and loss of contrast, according toLack &Southern (1949) andMarler (1960). The withdrawal of learning hypothesis is a better explanation.6. Blue Tits on Tenerife and Morocco are very closely related to each other but are probably not a different species from the Blue Tits of Europe.

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Für die Übersetzung danken wir FrauR. Jellis und HerrnP. Lundberg.     

β-Ionon und patchoulialkohol aus den unterirdischen teilen von Valeriana officinalis

l-(+)-Bornesitol was detected in 23 of 33 genera of Gentianaceae investigated. The only subtribe without l-(+)-bornesitol (3 species tested) was Exacinae. None of the five genera of Menyanthaceae examined were found to contain l-(+)-bornesitol.     

Some general aspects regarding the interpretation of binding data by means of a Scatchard plot

The question is quantitatively examined which general information can be obtained from experimental data of ligand binding to macromolecules if represented by a Scatchard plot. In particular, the curvature as well as the intercepts and slopes at both coordinate axes are analyzed assuming rather general conditions including cooperative behavior (with applications to some simplified cases of interest in practice). The results should provide a basis for attempts to elucidate the binding mechanism of a system encountered in experimental work.