Temperaturabhängiges Putzen bei Sammelwespen

The influence of temperature on the preening of foraging wasps (Paravespula vulgaris) collecting sucrose solution at an artificial food source is described. The temperature has an influence on the number of preening movements performed per unit time (= rate of preening) as well as on the spatial distribution of the preening movements. The rate of preening as a function of the temperature is explained in a quantitative manner using a diagram, which corresponds to the disinhibition hypothesis for displacement activities. This also holds true for the honeybee. The degree of disinhibition of the preening tendency does not determine the spatial distribution of the preening movements.     

Übersprungputzen bei der Larve vonAeschna cyanea Müll. (Odonata)

Zusammenfassung 1. Wird bei der Larve vonAeschna cyanea Müll. zunächst das beim Beutefangverhalten auftretende Übersprungputzen durch häufiges Auslösen ermüdet, so nimmt die Anzahl der anschließend auslösbaren Schnappreaktionen ab mit der Zunahme der Anzahl der Übersprungputzhandlungen.2. Für eine Erklärung reicht die Übersprunghypothese, wenn sie in zu einfacher Form oder ausschließlich herangezogen wird, nicht aus.

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Displacement preening in the larva ofAeschna cyanea Müll. (Odonata)

Displacement preening in larvae ofAeschna cyanea is performed in the course of searching behaviour whenever a prey-dummy is suddenly removed. Experiments with a group of animals of the same age, size and origin were carried out to show whether or not there is an influence of displacement preening on the prey-catching behaviour performed afterwards. In control tests all animals showed the snapping-response to a certain dummy 700 to 900 times. After a high number of preening actions, a reduction of the snapping activity was observed. The fact that the displacement preening, in contrast to that of the autochthonous preening, influences the prey-catching activity can be interpreted by a sparking-over of the specific action potential; but one should avoid taking a too simple approach to the conception of a sparking-over by the surplus-hypothesis.

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Herrn Professor Dr.Adolf Bückmann zum 65. Geburtstag in Verehrung gewidmet.

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Mit Hilfe der Deutschen Forschungsgemeinschaft.     

Vigilance during Preening in Coots Fulica atra

In birds, vigilance during feeding is usually linked with (1) the many‐eyes‐hypothesis, (2) the dilution effect, and (3) the intraspecific scramble competition hypothesis. To exclude competition for resources as a driving force in vigilance research into activities other than feeding is necessary. Additionally, variables such as nearest neighbour distance and position within a flock are supposed to influence vigilance and vigilance of singletons should be compared with vigilance of flock members. I studied vigilance during preening in Eurasian Coots (Fulica atra) and counted the number of scans per minute. A total number of 117 coots were sampled with 16 of them preening alone. Coots preening alone showed a significantly higher scan rate. I found a significant negative correlation between vigilance and flock size while nearest neighbour distance correlated positively with vigilance. Further, vigilance was higher in individuals at the edge. A general linear model using nearest neighbour distance and flock size within 10 m as covariates also revealed a significant influence of flock size but not of nearest neighbour distance. The centre‐edge effect still remained significant. These results indicate that flock size is the most influential predictor of vigilance in preening coots, followed by spatial organization. However, using nearest neighbour distance instead of flock size also produced a significant model as did the flock size measurement within a radius of 20 m. As scramble competition could be ruled out, the flock size effect may be indeed related to predation.     

Coccidial infection does not influence preening behavior in American goldfinches

Preening behavior in birds is important for the maintenance of thermoregulatory and ornamental functions of plumage. It has been repeatedly demonstrated that birds trade off time between plumage maintenance and other activities. However, the condition-dependent constraints of preening remain virtually unstudied. Here, we present the first experimental test of the hypothesis that intestinal parasite infection impairs preening activity. We studied male American goldfinches (Spinus tristis), a species with carotenoid-based plumage coloration. Following pre-alternate (spring) molt, we manipulated the health of males by infecting some birds with Isospora spp. coccidia and keeping others free of the infection. Although the goldfinches increased preening throughout the captive period, we found no significant effect of coccidial treatment on preening behavior. The effect of coccidia on plumage maintenance may be more pronounced under natural conditions where birds have limited access to food and engage in more activities that might limit time available for preening.     

Physiological and biochemical responses of <Emphasis Type="Italic">in vitro Fusarium oxysporum</Emphasis> f.sp. <Emphasis Type="Italic">niveum</Emphasis> to benzoic acid

The allelopathic potential of an artificially applied allelochemical, benzoic acid, on in vitro Fusarium oxysporum f.sp. niveum (a soil-borne pathogen causing watermelon wilt) was evaluated. Benzoic acid strongly inhibited its growth, sporulation and conidia germination, whereas it stimulated virulence factors of this pathogen. The biomass was reduced by 83–96 % and the conidia germinating rate and conidia production rate were decreased by 100 % at a concentration of >200 mg/L. However, phytopathogenic enzyme activities and mycotoxin production were stimulated with an increase of 10.2–1250 % for enzyme activities and 610–2630 % for mycotoxin yield.     

Inhibierungserscheinungen bei der alkoholischen Gärung,II. Einfluß der Substratkonzentration auf die spezifische Ethanolbildungsgeschwindigkeit von Saccharomyees cerevisiae

The influence of sucrose concentration on the specific ethanol production rate was studied during batch processes using the yeast strain Saccharomyces cerevisiae Hansen Sc 5. From experimental data a model could be derived for the simulataneous effect of substrate and product inhibition. It was found that both the decreases of fermentation activity of the cells caused by sucrose and ethanol have an additional relation to each other. This model also takes into consideration the fact that the maximum ethanol concentration P′ can't be realized at high substrate concentrations in a batch process. Compared to it sucrose concentrations below 100 g/l did not inhibit the ethanol production by the strain used in this investigation.     

The Inhibitory Effects of Garlic (<Emphasis Type="Italic">Allium sativum</Emphasis>) and Diallyl Trisulfide on <Emphasis Type="Italic">Alexandrium tamarense</Emphasis> and other Harmful Algal Species

Using cell suspension ability as an indicator, we studied the inhibitory effect of garlic (Allium sativum) and diallyl trisulfide on six species of red tide causing algae. This included: the inhibition by 0.08% garlic solution of five algal species — Alexandrium tamarense, Scrippsiella trochoidea, Alexandrium catenella, Alexandrium minutum and Alexandrium satoanum; the effects of garlic concentration on the inhibition of A. tamarense, S. trochoidea and Chaetoceros sp.; the effects of inhibitory time on the rejuvenation of algal cells; and the effects of heating and preservation time on algal inhibition by garlic solution. In addition, whether or not the ingredients of garlic solution had a possible algicidal effect was studied by comparing inhibition of A. tamarense by garlic solution and man-made diallyl trisulfide. The results showed that 1) inhibition by garlic solution was significant on A. tamarense, A. satoanum, A. catenella and S. trochoidea, and the least effective was a concentration of 0.04% on A. tamarense and S. trochoidea. Moreover, the higher the concentration, the stronger was the inhibition, and a high inhibitory rate (IR) could be maintained for at least three days when the garlic concentration was above 0.04%. For A. tamarense, it was also found that the longer the inhibitory time and the higher the concentration, the lower was the rate of resumed cell activity. On the contrary, garlic solution could not inhibit A. minutum or Chaetoceros sp.; 2) The IR to A. tamarense was reduced slightly as the heating time of the garlic solution was lengthened, but the average IR was still above 80%. There was no significant difference between the IR of the supernatant and sediment of the garlic solution. Furthermore, no change of algal inhibition was found when the garlic solution was preserved at 20°C for several days; 3) As with garlic solution, diallyl trisulfide inhibited A. tamarense strongly; the IR was above 93% and was maintained for at least three days, as long as the concentration was 3.2–10.0 mg L⁻¹. Thus, diallyl trisulfide may have been the major ingredient in garlic solution which inhibited the algae but, in addition, more than one ingredient may have been inhibiting the algae. In conclusion, garlic was a good algal inhibitor with many advantages, such as being common, cheap, non toxic and with high efficiency, and diallyl trisulfide, one of the components of garlic, was similarly effective in algal inhibition. It would be useful, therefore, to further study garlic as an environmentally friendly algal inhibitor.     

The effect of substituted amides of pyrazine-2-carboxylic acids on flavonolignan production in <Emphasis Type="Italic">Silybum marianum</Emphasis> culture <Emphasis Type="Italic">in vitro</Emphasis>

In vitro plant tissue and cell cultures were used to study herbicide effects on growth, selected metabolic activities and other phenomena. The effect of abiotic elicitors, two newly synthesized substituted amides of pyrazine-2-carboxylic acids (synthesized at the Department of Pharmaceutical Chemistry and Drug Control, School of Pharmacy in Hradec Kralove), on the flavonolignan accumulation in callus and suspension culture of Silybum marianum (L.) Gaertn. was investigated. The compounds markedly influenced production of flavonolignans in an in vitro culture. Particularly after the elicitation with a solution of compound 3-methylamide 5-tert-butylpyrazine-2-carboxylic acid at a concentration of 3.71×10⁻⁷ mol 1⁻¹ and within 72 h of elicitation, an increase in flavonolignan production by 893 % in suspension culture versus control took place. The flavonolignan accumulation in callus culture after the elicitation with a solution of 5-brom-2-hydroxyphenylamide of 5-tert-butyl-6-chloropyrazine-2-carboxylic acid was also increased by about 1039% (24 hour elicitation and concentration of 2.59×10⁻⁴ mol 1⁻¹).     

Über die Adsorption von DNS in der Grenzfläche Quecksilber–Elektrolyt

The adsorption of deoxyribonucleic acid (DNA) in the mercury–electrolyte interface has been investigated. The effect of this adsorption on the differential capacity of the electrical double layer between a polarized mercury surface and an 0.15M NaCl solution containing DNA was measured by means of the alternating current polarography (Breyer polarography). The effective alternating current ? under actual conditions (adsorption processes only, small electrolytic resistance, small alternating current frequency, and alternating current amplitude) is directly proportional to the differential double layer capacity. The combination of this method with the application of a stationary mercury drop electrode allows the coverage of the electrode to be followed, continuously in the range 0.2 sec, to about 60 sec. The diffusion is the rate-controlled step of the adsorption kinetics. Therefore the lowering of the alternating current ? by the adsorbed DNA is proportional to the surface concentration for partly covered surface and reaches a constant value after the surface becomes fully covered. Adsorption of further layers does not affect the differential capacity. This makes it possible to determine the maximum surface concentration of the DNA. For that it is necessary to determine the diffusion coefficient of DNA. This was done directly by Strassburger and Reinert in our institute. The surface concentrations of the native DNA and the relative surface concentrations of the denatured DNA in dependence on the potential of the polarized mercury surface was estimated. Both surface concentrations show a pronounced dependence on the potential with a minimum of the surface concentration around ?0.4 V with respect to the normal calomel electrode. This property may be caused by the structure of the adsorption layer depending on the potential. That means that only several segments at the rigid DNA molecules are adsorbed and the other ones remain in the solution near the surface. The adsorption in the neighborhood of the electrocapillary zero potential at ?0.4 V is strongest, and therefore the fraction of the adsorbed segments has a maximum. At these potentials consequently the maximum coverage is already reached at relatively low surface concentrations. Opposite to this is Miller's hypothesis, that native DNA preserves its double helical structure when adsorbed on a negatively charged mercury surface, whereas unfolding occurs on a positively charged mercury surface. Miller's hypothesis is supported by facts that the surface concentration of the denatured DNA should be independent of the potential and should be equal to the surface concentration of the native DNA at a positively charged mercury surface. But an evaluation of Miller's diagrams by no means gives an independence on the potential of the surface concentration of the denatured DNA and no accordance between the surface concentrations of denatured and of native DNA's at the positively charged mercury surface. Moreover Miller compared different DNA samples with different moleculer weights and possibly with different molecular weight distributions. Both the molecular weight and the molecular weight distribution have a pronounced influence on the surface concentration. Therefore this accordance mentioned above is not evident. The critical inspection of Miller's work and the own investigation lead to the conclusion that an unfolding or denaturation of native DNA does not take place in the mercury–electrolyte interface.     

Patch residence decisions made by Aphidius colemani in the presence of a facultative predator

One of the key questions in ecology is how animals optimally allocate their time in an environment with patchily distributed resources and competing organisms. Here we investigate the effects that an aphid predator, Macrolophus caliginosus (Wagner) (Hemiptera: Miridae), has on the searching behavior and the patch residence decisions of an aphid parasitoid, Aphidius colemani (Viereck) (Hymenoptera: Aphidiidae). A computer programme was designed that allowed the recording and saving of direct observations. The time allocated to different activities by a female parasitoid wasp in the presence or absence of the predator M. caliginosus was investigated. The experiments were conducted under controlled environment conditions using leaves of sweet pepper, Capsicum annuum L. (Solanaceae) and Myzus persicae (Sulzer) (Hemiptera: Aphididae) as the host plant–prey species system. The parasitoid spent significantly less time on ‘secondary’ activities, such as preening and resting, when the predator was present. Survival analysis showed that the parasitoid had a higher patch-leaving tendency when the predator was present.     

Operation of packed-bed immobilized cell reactor featuring active β-galactosidase inclusion body-containing recombinant <Emphasis Type="Italic">Escherichia coli</Emphasis> cells

In this study, we developed a packed-bed immobilized cell reactor containing active β-gal (β-galactosidase) inclusion body (IB)-containing Escherichia coli (E. coli) cells in alginate beads. This packed-bed reactor was operated using a substrate feed solution 0.72 ∼ 38.4 mM ONPG (o-nitrophenyl-β-D-galactoside) prepared in Z buffer supplemented with chloroform and 0.1% SDS (sodium dodecyl sulfate). The production rate of ONP (o-nitrophenol) in the reactor containing cells that were incubated with α-MG (α-methyl D-glucospyranoside) or D-fucose after induction was superior to those prepared with cells that were not incubated with α-MG or D-fucose. The ONP production rate was increased proportionally with ONPG concentration in the substrate feed up to a concentration of 38.4 mM. However, as the ONPG concentration was increased in the substrate feed solution, galactose inhibition inside the alginate beads was increased. This most likely occurred due to problems with diffusion. In addition, partial breakage of alginate beads was observed during the later periods of operation. In this study, we demonstrated that active β-gal IB-containing E. coli cells were sustained in the immobilized cell reactor during operation. Particularly, these findings demonstrate the feasibility of using active IBs in an enzymatic reaction without the need for any purification step. In addition, we showed that these IB-containing cells could be directly used in an immobilized reactor.     

Behaviour of <Emphasis Type="Italic">Odontomachus chelifer</Emphasis> (Latreille) (Formicidae: Ponerinae) Feeding on Sugary Liquids

Sugary solution intake behavior by Odontomachus chelifer (Latreille), is studied. The feeding mechanism involved is described. Effects of sucrose concentration and solution viscosity on ingested load, feeding time and rate of liquid intake are assessed. Suction was always the feeding mechanism, regardless of concentration or viscosity of the solution. There were no differences in loads ingested for concentrations of up to 30% w/w, but feeding took longer at this concentration. Liquid intake rates were higher at the lowest concentrations. Above 40% w/w, values of all three variables were smaller. O. chelifer’s ability to ingest mildly viscous fluids could be related to its capacity to ingest other viscous fluids present in its diet.     

Allelochemical stress produced by aqueous leachate of <Emphasis Type="Italic">Nicotiana plumbaginifolia</Emphasis> Viv.

The effects of aqueous leachate of Nicotiana plumbaginifolia Viv. on germination, seedling growth, amylase activity, sugar and starch contents of germinated seeds of maize (Zea mays L. cv. Uttam) were examined. Effects of leachate on photosynthetic pigments, protein content, activities of nitrate reductase and some antioxidants were also studied. Higher concentration of aqueous leachate of N. plumbaginifolia reduced the germination rate (GR). However, final germination percentage remained almost unaffected. Lower concentration of leachate stimulated the amylase activity and resulted in higher sugar content and GR. The increasing concentrations of leachate inhibited the conversion of starch into sugars. Allelochemicals decreased the amount of chlorophyll a, chlorophyll b, carotenoids, protein and nitrate reductase activity (NRA). The leachate of lower concentrations stimulated the activity of peroxidase but slight decrease was recorded in higher concentration. Superoxide dismutase and catalase exhibited concentration dependent increase except in seedlings treated with 100% concentration of leachate. Impairment of various metabolic activities due to leachate resulted in decreased root and shoot length.     

Effect of root applied 24-epibrassinolide on carbohydrate status and fermentative enzyme activities in cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.) seedlings under hypoxia

The effects of 24-epibrassinolide (EBR) added to nutrient solution on growth of cucumber (Cucumis sativus L.) under root-zone hypoxia were investigated. Cucumber seedlings were hydroponically grown for 8 days in normoxic and hypoxic nutrient solutions with and without addition of EBR at 1 μg l⁻¹. EBR exerted little influence on plant performance in the normoxic nutrient solution, while the chemical alleviated root-zone hypoxia-induced inhibition of root and shoot growth and net photosynthetic rate (Pn). EBR added to hypoxic nutrient solution caused an increase in the concentration of fructose, sucrose, and total soluble sugars in the roots but not in the leaves. Root-zone hypoxia enhanced the activities of lactate dehydrogenase (LDH), alcohol dehydrogenase (ADH), and pyruvate decarboxylase in the roots. Interestingly, EBR further enhanced ADH activity but lowered LDH activity in hypoxic roots. These results suggest that EBR added to hypoxic nutrient solution may stimulate the photosynthate allocation down to roots and the shift from lactate fermentation to alcohol fermentation in hypoxic roots, resulting in the increase in ATP production through glycolysis and the avoidance of cytosolic acidosis and eventually enhanced tolerance of cucumber plants to root-zone hypoxia.     

Vergleich von Messungen des kLa-Wertes nach der stationären und der dynamischen Methode bei der Fermentation von L-Lysin und Turimycin

The calculation and scale-up of fermentation processes need k_La as one of the most important engineering data. There are two methods to determine k_La depending on power input, aeration rate and the properties of the fermentation broth: static with a balance between air supply and exit, dynamic gassing out with following the changes of dissolved oxygen concentration during periods of air off and a following air on. Within early intervals of fermentation time the data from both methods agree well, while for later time intervals the dynamic method always gives much lower values for k_La than static. The only explanations for this phenomenon are quick changes in the oxygen metabolism or an enzymatic storage of oxygen. For both gassing out and saturation period it is possible to calculate the same absolute amounts of this additional oxygen.     

Hydrolysis of insoluble cellulose to glucose catalyzed by cellulase‐containing liposomes in an aqueous solution of 1‐butyl‐3‐methylimidazolium chloride

The liposome containing cellulase from Trichoderma viride was prepared under the condition that an appreciable amount of cellulase was incorporated in lipid membranes. The liposomal cellulase and free enzyme were examined in their hydrolytic activities to insoluble cellulose powder CC31 in the acetate buffer solution (pH 4.8) of 15 w/w% [Bmim][Cl] (1‐butyl‐3‐methylimidazolium chloride). The mean diameter and size distribution of cellulase‐containing liposome were practically unchanged under the above condition. The free cellulase was deactivated more rapidly than the liposomal cellulase in catalyzing the hydrolysis of 2.0 g/l CC31 at 45°C in the presence of [Bmim][Cl] for 48 h. The activities of liposomal and free cellulase to cellobiose as soluble substrate were less susceptible to [Bmim][Cl] than their cellulolytic activities to CC31, meaning that β‐glucosidase is relatively stable among the three enzyme components of cellulase. The rate of glucose production could be appreciably improved by the pretreatment of CC31 with [Bmim][Cl] alone at 120°C for 30 min followed by the liposomal cellulase‐catalyzed hydrolysis of the substrate at 45°C at the [Bmim][Cl] concentration of 15 w/w%. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1190–1196, 2013     

Inhibierungserscheinungen bei der alkoholischen Gärung,I. Einfluß der Ethanolkonzentration auf die spezifische Ethanolbildungsgeschwindigkeit von Saccharomyces cerevisiae

Differential values of the specific ethanol production rate \documentclass{article}\pagestyle{empty}\begin{document}$$ v_{(t)} = \frac{1}{{x_{(t)} }} \cdot \frac{{dP}}{{dt}} $$ \end{document} can be calculated exactly from experimental batch fermentation process data by use of a nonlinear regression programme. The method used is based on the fact, that the function P = f(t) can be approximated by an exponential equation. The specific ethanol production rate is calculated then from the first differential derivation of this equation using the appropriated values of actual biomass concentration. For two strains of Saccharomyces cerevisiae a linear and nonlinear kinetic pattern, respectively, was found for product formation. This result can be explained by a simple mathematical relation according to ν=ν₀ ? a . P^b,in which the exponent becomes 1 in the case of linear kinetic pattern.     

Der Einfluß der Konzentration von Ethanol und Essigsäure auf den Adenylat-Pool bei Acetobacter Rancens

The influence of ethanol and acetic acid concentration on the ATP-pool and energy charge of Acetobacter rancens was investigated. The behaviour of growth and ATP-pool is contrary one to each other. An increasing concentration of acetic acid results in decreased growth rate, ATP-pool and energy charge.     

An analysis of displacement preening in the domestic fowl

The preening behaviour of the domestic fowl was filmed under both normal and thwarting conditions. The film was analysed frame by frame and the duration of individual preening movements was measured. It was found that preening movements in the thwarting situation were of shorter duration than those in the normal situation and it was thought that this accounted for the ‘frantic’ appearance of the displacement preening. The pattern of preening also differed in the thwarting situation with plumage areas which were easy to reach receiving more attention than in the control situation.