High ethanol productivities using small Ca-alginate beads of immobilized cells of Zymomonas mobilis

Summary Zymomonas mobilis cells were immobilized into small 1 mm diameter beads of Ca-alginate in order to minimize mass transfer limitations and maximize immobilized cell activity. A combination of small bead size with a high cell concentration of 58 g dry wt. cell per lit. bead volume resulted in high ethanol productivities using a newly designed packed bed bioreactor system. Steady-state dilution rates ranging from 0.4 h^-1 to 3.9 h^-1 were run resulting in a maximum productivity of 102 g ethanol/l/h for an inlet substrate concentration of 100 g glu/l and 87% conversion. The bioreactor was run continuously at a fixed dilution rate for 384 h and short intermittent treatment of the beads with CaCl₂ temporarily increased ethanol productivity to a maximum of 116 g ethanol/l/h.     

Experiments on the abiotic amplification of optical activity

Our earlier experiments are briefly reviewed, involving the abiotic generation of optical activity by exposure of DL-amino acids to various chiral physical forces. The enantiomeric enrichments so obtained were low, however, and additional experiments were undertaken with the objective of abiotically enhancing such small enantiomeric excesses. DL Mixtures of leucine N-carboxy anhydride gave enantiomerically enriched polymers on partial polymerization, while valine NCA mixtures behaved oppositely. Leucine polymers were also found to hydrolyze stereoselectively, providing for additional enantiomenic enhancement. A repetitive sequence of partial polymerization-hydrolysis steps is suggested as a possible mechanism for the abiotic genesis of optically enriched polypeptides on the primitive Earth.     

Inhibition of dihydropteridine reductase by dopamine

Dihydropteridine reductase has been purified 900-fold from rat liver. Dopamine inhibited the enzyme up to 50% at a concentration of 0.11mm. In the presence of dopamine the enzyme gave non-hyperbolic v-against-[S] plots. This enzyme may have a role in control of dopamine biosynthesis.     

Canarion,ein neues naphthochinon aus Usnea canariensis

The structure of canarione, a new naphthoquinone from the lichens Usnea canariensis and U. hookeri was elucidated by UV, ¹H-NMR, ¹³C-NMR, mass spectrometry, and chemical degradation as 5,8-dihydroxy-2-methyl-4H-naphtho [2,3b]-pyran-4,6,9 (6H, 9H)- trione.     

Synthese der lunularsäure

A ten-step synthesis of lunularic acid, starting from phenyl β-chloropropionate is described. Detailed spectroscopic data are given for lunularic     

The phosphorus efficiency of three annual legumes

Summary Trifolium subterraneum, Trifolium glomeratum andOrnithopus compressus were grown in soil and solution culture at varying P concentrations. Efficiency of P utilization was determined using the following criteria: (1) The ability to produce tops dry matter with a given amount of applied P, (2) Tops dry matter produced per unit of P taken up, (3) Tops dry matter produced at a constant plant P level and (4) Phosphorus uptake per unit root weight. The order of efficiency varied according to the crieteria used. Using the agronomic definition (1), Serradella was the most efficient species at 70 days. The need to clearly define what is meant by an efficient species is demonstrated.     

The synthesis and intracellular localization of adenovirus hexon protein studied by microinjection of mRNA into human cells

Polyadenylated RNA isolated 18 h after infection of HeLa cells with adenovirus type 2 was both translated in vitro and microinjected into the cytoplasm of human transformed amnion cells. The hexon polypeptide could be specifically immunoprecipitated from the products of cell-free translation with a rabbit-anti-hexon serum. The same serum when used in immunofluorescence assays of microinjected cells revealed hexon protein synthesized 6 h after microinjection. The intensity of the staining persisted up to 16 h after injection of messenger RNA (mRNA). Newly-synthesized hexon protein was characteristically located mainly in the nucleus. Essentially the same results were obtained when normal amnion cells were microinjected.     

Influence of temperature on hatching of eggs of Lepidurus couesii (Crustacea,Notostraca)

Tadpole shrimps (Notostraca) occur sporadically in temporary ponds and their survival there depends largely upon the drought-resistant eggs they produce. Environmental conditions conducive to hatching of eggs of Lepidurus couesii were investigated in the laboratory. Almost all eggs hatched best at 20 °C, whether desiccated for a short or long period, with a prior freezing shock or without such a shock, with intact shells. Eggs that endured a longer period of desiccation and eggs with abraded shells displayed a more equivocal response to different temperatures for hatching. Long-term hatchability of eggs was demonstrated. Time required for successful hatching was shortest at 20 °C, with no discernible difference between 17 °C and 25 °C. Both short- and long-term survival of populations of the species appears to be fostered by the adaptive response to temperature shown by the eggs.     

Pnoepyga immaculata n. sp., eine neue bodenbewohnende Timalie aus dem Nepal-Himalaya

Zusammenfassung Pnoepyga immaculata n. sp. lebt im Areal der beiden anderenPnoepyga-Artenalbiventer (Hodgson 1837) undpusilla Hodgson 1845 und wurde durch ihren markant abweichenden Territorialgesang entdeckt. Sie besitzt eine kurze silberhelle Strophe aus kurzen, in gleichmäßigen Abständen gereihten Pfiff-Elementen, die in der Frequenz leicht abfällt. Neben der Stimme liegen die wesentlichen diagnostischen Merkmale nach jetzigem Kenntnisstand gegenüber sympatrischenalbiventer in wenig größerem Schnabel, der Fleckenlosigkeit von Oberseite, Kopf und Flügeldecken, gegenüberpusilla in den größeren Körperabmessungen, gegenüber sympatrischenalbiventer undpusilla im schwachen grünlichen Schimmer der Oberseite und in der länglichen Schuppung der Unterseite. Es bestehen keine Proportionsunterschiede zwischenimmaculata undalbiventer/pusilla einerseits wie auch nicht zwischen diesen beiden andererseits. Bis jetzt wurden 4 Belegstücke (SammlungenKoelz, Diesselhorst, Martens) und eine durch Bandaufnahme gesicherte Beobachtung zwischen Dhaulagiri in Mittelwest-Nepal bis nahe der Ost-Grenze Nepals bekannt.P. immaculata lebt zur Brutzeit in enger Nachbarschaft mitP. albiventer undP. pusilla, ist jedoch vonalbiventer vertikal getrennt bei nachgewiesenem Kontakt, vonpusilla durch Bevorzugung trockeneren Waldunterwuchses abseits von Bächen. Schon jetzt mußimmaculata als gefährdete Art eingestuft werden, da Waldvegetation in der zur Brutzeit bevorzugten Höhenstufe zwischen 2100 und 3100 m in Nepal weitgehend vernichtet worden ist.

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Pnoepyga immaculata n. sp., a new ground living wren-babbler from the Nepal Himalayas (Timaliidae)

Summary P. immaculata n. sp. was discovered by its voice which strongly differs from the two other sympatric species,albiventer (Hodgson 1837) andpusilla Hodgson 1845. As a territorial song, it displays a silvery strophe arranged of short, more or less regularly spaced whistling notes (fig. 7a–d), slightly descending in pitch. The strophe is about 2 s long. Besides the distinct voice, the essential diagnostic characters in comparison toP. albiventer are the slightly larger bill, plain head, upper side and wing coverts (fig. 1a–d, 2, 4a–d), in comparison topusilla the larger body size (fig. 1i–m), in comparison to sympatricalbiventer andpusilla the slightly olive tinge of the upper side (against warm dark brown in both others, fig. 1e–m), and the more longish scaly feathers of the lower side (against stout scaly appearance in both others, fig. 1 a–d). These characters hold true at least in Central and Eastern Himalayan populations of the respective species. There do not exist proportional differences in the relations of any part of the body betweenimmaculata andpusilla and not between the latter ones as well. Heretofore, 4 museum specimens are known (Koelz Coll.,Diesselhorst Coll.,Martens Coll.) from West-central (Thakkhola, type locality) and East Nepal (Ting Sang La), 3 of them from the presumed breeding grounds (2100–3100 m), one from the winter quarters in the Terai lowlands. A field observation close to the Darjeeling border in far East Nepal is verified by a tape-recording.P. immaculata embarasses the biologist and systematist because it lives in close neighbourhood of the similar speciesalbiventer andpusilla. It must have been overlooked by its apparent scarcity and overall similarity to both other species of the genus. Slight ecological differences rather correspond to the vertical distribution ofalbiventer, which populates a higher forest belt. But both have already been found on territory at close range.P. pusilla inhabits different microbiotopes, especially the close proximity of running water in the same altitudinal belt asimmaculata. When discovered,P. immaculata is to be classified already as an endangered species. Forest vegetation of its preferred altitude is already greatly reduced in the Central and Eastern Nepal Himalayas. To get a more detailed information on its general distribution and biology in order to quickly arrange protected areas and thus to guarantee the survival ofP. immaculata, should be the urgent next step.

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Results of the Himalaya Expeditions ofJ. Martens, No. 163. — For No. 162 see: Stuttgarter Beitr. Naturkde. (A) 453: 1–46, 1990.     

Enantiospecific quantification of hexobarbital and its metabolites in biological fluids by gas chromatography/electron capture negative ion chemical ionization mass spectrometry.

A highly sensitive and specific assay based on gas chromatography/electron capture negative ion chemical ionization mass spectrometry has been developed for the analysis of the enantiomers of hexobarbital and its major metabolites in human urine and plasma. S-(+)-(5-2H3)hexobarbital and R-(-)-(5-2H3)hexobarbital were synthesized for clinical studies along with (+/-)-(1,5-2H6)hexobarbital and the deuterated major metabolites for use as internal and reference standards. Hexobarbital enantiomers and their metabolites were analyzed after pentafluorobenzyl and trimethylsilyl derivatization, following solid-phase extraction from plasma and urine. Intense negative ion spectra were observed for all of the derivatives. The base peak in the spectra corresponded to the M-pentafluorobenzyl anion [M-PFB]- except for 1,5-dimethylbarbituric acid, where M-. was the most abundant ion. The applicability of the method was demonstrated by following the plasma concentration-time profiles and urinary excretion in a male extensive metabolizer of mephenytoin who was given a pseudoracemic oral dose of hexobarbital containing equal 50 mg amounts of S-(+)-2(H0)hexobarbital and R-(-)-(2H3)hexobarbital. Marked stereoselective disposition was observed, with the R-(-)-enantiomer being more efficiently metabolized, primarily by alicyclic oxidation and ring cleavage.