A reduced specific ethanol-forming performance of yeast at high biomass concentrations as a result of a changed ethanol-tolerance behaviour of the cells under condition of limitation. II. Proving the effect in high-flow rate fermentations with saccharomyces cerevisiae Sc 5

In growth-factor limited fermentations carried out in continuous high-flow rate fermenters the relationship existing between the specific ethanol formation rate and the ethanol concentration was found to change its characteristics from a linear function into a nonlinear one at high biomass concentrations. The deviation from the linear inhibitory behaviour of the cells was the greater the more the biomass concentration increased. A very good correspondence between the experimentally found productivities of ethanol formation and its adequate values obtained by calculation could be attained by using an improved steady-state productivity model, in which the variability of the function v = f(P) had been considered.     

The amino acid sequence of the cytochrome c-554(547) from the chemolithotrophic bacterium Thiobacillus neapolitanus.

An amino acid sequence is proposed for the cytochrome c-554(547) from the bacterium Thiobacillus neapolitanus N.C.I.B. 8539). It consists of a polypeptide chain of 91 residues, with a pair of haem-attachment cysteine residues at positions 15 and 18. There is similarity in sequence with each of the halves of the sequence of the dihaem cytochromes c4 and with a cytochrome c-554(548) from a halophilic strain of Paracoccus. Detailed evidence for the amino acid sequence of the protein has been deposited as Supplementary Publication SUP 50127 (11 pages) at the British Library (Lending Division), Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1985) 225, 5.     

Spectral resolution of cardio-circulatory variations in men measured by autorhythmometry over 2 years

An analogue of the periodogram method for unequally spaced data is presented with a view to resolving the frequency structure of the observations. The algorithm is explicitly based on the sequential least squares procedure. In particular, the key concept is that the with-in-plot spectral analysis can be augmented by the between-plot information to make inferences about common characteristics. It is also shown how the between-plot random variations can be incorporated into the multiple harmonic regression model. A detailed spectral analysis investigates the periodic fluctuations in four cardio-circulatory variables, measured by autorhythmometric observation by eight men at rest and extending over a time span of 2 years. The spectral curves show the existence of circadian and circaseptan rhythmicities. The amplitude modulation of the dian rhythm by circaseptan variation is assimilated with the rhythmicity of work during the week. The blood-pressure variables situate their maximum annual peak in the winter period. These quasi-periodic fluctuations appear to be related to the amount of physical activity performed in time by the subjects.     

Energy profile of maltooligosaccharide permeation through maltoporin as derived from the structure and from a statistical analysis of saccharide-protein interactions.

The crystal structure of the maltodextrin-specific porin from Salmonella typhimurium ligated with a maltotrioside at the pore eyelet is known at 2.4 A resolution. The three glucose units assume a conformation close to the natural amylose helix. The pore eyelet fits exactly the cross-section of a maltooligosaccharide chain and thus functions as a constraining orifice. The oligomer permeates the membrane by screwing along the amylose helix through this orifice. Because each glucose glides along the given helix, its interactions can be sampled at any point along the pathway. The interactions are mostly hydrogen bonds, but also contacts to aromatic rings at one side of the pore. We have derived the energy profile of a gliding maltooligosaccharide by following formation and breakage of hydrogen bonds and by assessing the saccharide-aromatics interactions from a statistical analysis of saccharide binding sites in proteins. The resulting profile indicates smooth permeation despite extensive hydrogen bonding at the orifice.     

Cerebrospinal fluid gamma aminobutyric acid levels in migraine.

Gamma-Aminobutyric acid (GABA) levels in cerebrospinal fluid were measured in seven patients with tension headache and 12 patients with migraine. GABA was detected only during the migraine attack. The results suggest disordered GABA metabolism in migraine.     

Sex pheromone of the female currant borer, Synanthedon tipuliformis: Identification and field evaluation

(E,Z)-2,13-octadecadien-1-ol acetate and (Z)-13-octadecen-1-ol acetate have been identified from the ovipositor extracts of the currant borer, Synanthedon tipuliformis (Clerck), by capillary GC, and the structures were verified by GC-MS. The diene/monoene ratio in the extract was found to be 93:7. Mixtures of these two compounds as well as the diene alone attracted conspecific males in the field.

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Zusammenfassung (E,Z)-2,13-Octadecadienylacetat und (Z)-13-Octadecenylacetat wurden in Ovipositor-Extrakten des Johannisbeerglasflüglers Synanthedon tipuliformis kapillar-gaschromatographisch nachgewiesen. Die Strukturen wurden mittels Gaschromatographisch-Massenspektrometrie bestätigt. Das Verhältnis Dien/Monoen im Extrakt betrug 93:7. Mischungen der beiden Komponenten wie auch (E,Z)-2,13-Octadecadienylacetat allein lockten im Freiland Männchen dieser Glasflüglerart an.