Lectin-like binding of lactobacilli considered for their use in probiotical preparations for animal use

Three gut lactobacilli from piglets (Lactobacillus plantarum L 5, Lactobacillus paracasei L 81, Lactobacillus fermentum L 670) and Lactobacillus casei subsp. pseudoplantarum L.c.) from a calf were examined by microtitre plate binding assay for their lectin-like binding activity after their cultivation on Rogosa agar and in MRS broth. Three ECM (extracellular matrix) molecules (fetuin, porcine fibronectin and porcine mucin) were selected for this assay. Additionally, the effect of heparin on the binding of these three ECM molecules by Lactobacillus strains in microtitre plates was tested. Moreover, haemagglutination tests with pig, cattle, sheep, and hen erythrocytes were performed. However, none of the four Lactobacillus strains examined did react with any of the erythrocytes tested. The differences between individual strains were observed in their binding to immobilised ECM molecules. The best adherent was the Lactobacillus plantarum L5, however, the other three strains showed also good ECM binding. With regard to an influence of cultivation medium on lectin-like binding activity, binding of all ECM molecules was expressed in Lactobacillus paracasei L 81 to significantly higher degree (P < 0.001) after cultivation on Rogosa agar than in MRS broth. Similarly, strains Lactobacillus fermentum L 670 and Lactobacillus casei subsp. pseudoplantarum L.c. displayed significantly higher (P < 0.001) binding of fibronectin and mucin after growth on Rogosa agar in comparison with MRS broth cultivation. However, no significant (on fetuin and fibronectin binding) or opposite effect (on mucin binding) of cultivation medium was observed in Lactobacillus plantarum L 5 strain. The influence of cultivation medium on fetuin binding by Lactobacillus fermentum L 670 was also not significant while Lactobacillus casei subsp. pseudoplantarum L.c. bound fetuin significantly better (P < 0.01) after growth on Rogosa agar. Heparin pretreatment increased the binding of the ECM molecules by the Lactobacillus fermentum L 670 strain significantly (P < 0.001 or P < 0.05) with the exception of porcine fibronectin when the strain was cultivated in MRS broth. This result is important especially in the connection with the previous observations that heparin decreased ECM binding of enteropathogens as staphylococci or clinical enterococcal isolates. Following up on some earlier strain characteristics, these results indicate that the selected lactobacilli are probably suitable for probiotic purposes.     

Über die Wirkung von Bacillus thuringiensis kombiniert mit synthetischem Pyrethroid auf Orgyia antiqua L.

The efficacy of the biopreparations Dipel and Thuricide HP in combination with the pyrethroid Permethrin, and that of Permethrin in the control ofOrgyia antiqua larvae has been tested in the field. The results indicate that these preparations may replace satisfactorily insecticides of the group of chlorated carbohydrates, and organophosphates, in the control ofOrgyia larvae. The persistence of spores of both Dipel and Thuricide was found to be good on the pine needles. The main advantage of the tested preparations is their complete harmlessness to vertebrates. Since they do not contaminate the external environment, they can be used safely in the treatment of large areas of infected forest stands located at the site of important water resources and recreation areas.     

Stabilität und Wirksamkeit eines Präparates von Bacillus thuringiensis var. israelensis gegen Mückenlarven im Freiland

Zusammenfassung Die Stabilität und Wirksamkeit eines Präparats vonBacillus thuringiensis var.israelensis (Sporen und Kristalle in Pulverform) gegen Stechmücken wurde in einem kleinen Feldversuch erprobt. Das Präparat wirkte äußerst rasch und mit großer Wirkungskraft aufCulex- undAedes-Larven. Es blieb während der Dauer unseres dreimonatlichen Versuchs unter natürlichen Wetterverhältnissen (Sonnenbestrahlung, Niederschläge, max. Temp. 29°C, min. Temp. –5°C) aktiv. Ein Nachteil war jedoch das Absinken des Sporenmaterials in die unteren Wasserschichten.

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Fieldstability and efficacy of a preparation of Bacillus thuringiensis var. israelensis against mosquito larvae

SporulatedBacillus thuringiensis var.israelensis was used in powder form in a small field trial against larvaeCulex andAedes. The preparation was found to be quickly and highly active. It did not lose its activity during the three months experiment under natural climatic conditions (sunlight, rain, maximal temperature 29°C, minimal temperature –5°C). Its disadvantage was the settling of spores in the bottom layers of the water column.

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Mit 2 tabellen     

Cytokinin, auxin, and abscisic acid dynamics during flower development in white and red currants infected with Blackcurrant reversion virus

Blackcurrant reversion virus (BRV) infection, characteristic by flower malformation, resulted at the early flower stage in elevated levels of bioactive cytokinins and their biosynthetic precursors in flowers of white currant ‘Blanka’ and red currant ‘Vitan’. In healthy flowers, flower-to-berry transition was accompanied by an increase in bioactive cytokinins that was not observed in infected flowers, which were incapable of further development. Auxin levels increased during flower development, in ‘Vitan’ only in flowers with normal morphology (both healthy and infected). BRV infection did not have a significant effect on cytokinin or auxin levels in the leaves of either cultivar, it coincided with a mild elevation in the content of abscisic acid in the flowers of both cultivars.