On tannic acid fixation and staining

Tannic acid was found to fix and stain glycocalyx heavily. After removal of the major component of surface glycopeptides by trypsin, the surface coat was stained vaguely, and after the treatment with collagenase, the surface coat was moderately stained. It is concluded that tannic acid stained non-specific surface glycopeptides.     

Zur Taxonomie von Rhodopseudomonas palustris

Zusammenfassung Eine Reihe von Rhodopseudomonas palustris-Stämmen aus verschiedenen Herkünften wurden vergleichend unter Verwendung folgender Merkmale untersucht: Substratverwertung, in vivo-Absorptionsspektrum und Serologie der O-Antigene. Die gegen 2 Stämme gerichteten Antiseren zeigen hohe Spezifität. Die Verwendbarkeit der serologischen Kreuzreaktion für taxonomische Untersuchungen bei photosynthetischen Bakterien wird diskutiert.

---

On the taxonomy of Rhodopseudomonas palustris

Summary Strains of Rhodopseudomonas palustris isolated from different habitats were compared with respect to their taxonomic features. All strains grew very well on formiate, acetate, propionate, butyrate, aspartate, inositol, ethanol, fructose, and p-amino-benzoate, respectively, as single carbon source. Most of the strains were able to use benzoic acid or glucose, too. But alanine was not found to be a good substrate. The maxima of the bacteriochlorophyll in-vivo-absorption spectra were estimated to be 376, 589, 802–805, and 858–875 nm. The shift of the infrared peak in the different strains is loosely correlated with the change of the carotenoid in vivo spectrum, the maxima of which were measured to be 470–480 nm (shoulder) 495–505 nm, and 520–545 nm (shoulder). Antisera were prepared against the strains 1e5 and 11/1. It was demonstrated that these antisera were directed against the lipopolysaccharides (O-antigen) of these bacteria. The antigen of 1e5 does not cross react with the antigen of 11/1. Strain 1e5 is the only one of 17 strains tested which is sensitive to the bacteriophage Rp1. The antigen of this strain cross reacted only with the antigen of strain K1. In contrast, the antigen of strain 11/1 cross reacted in some degree with most of the tested strains of Rps. palustris. No or very weak cross reaction was observed between the antigens of Rps. palustris (1e5, 11/1) and Rps. capsulata, Rps. spheroides, or R. rubrum, respectively. In contrast to 11/1 only heat-killed cells of strain 1e5 were agglutinated by anti-1e5.

---

Im Text verwendete Abkürzungen LPS Lipopolysaccharid - R Rhodospirillum - Rps. Rhodopseudomonas - i.m. intramuskulär - s.c. subcutan - i.v. intravenös     

Reactivity of neurons of the orbito-frontal cortex of the cat during exposure to the scent or sight of food

Reactivity of neurones in orbitofrontal cortex of the cat to the action of light or sound was studied in consecutive stages of alimentary behaviour conditioned by the smell and then the sight of food. Changes were found of the character of neuronal reactions to the light and sound stimuli at the change of smell to the sight of food. A conclusion is drown, that polysensory properties of the neurones of the orbitofrontal cortex provide integral organization of brain sensory function at separate stages of alimentary behaviour.