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A Gram-positive anaerobic bacterium was regularly found in great numbers in histological sections and anaerobic cultures of the third bulbous mid-gut portion of Pyrrhocoris apterus (Linne 1758). It formed long chains of irregular pear-shaped cells with large spherical involutions. The fermentation products were L -lactic acid, ethanol and acetic acid, CO2 and H2. The peptidoglycan belongs to the Lys-Asp type. The G + C content was determined to be around 61 mol%. The organism is supposed to be a symbiont of P. apterus and to be a species of a new genus. In the aerobic cultures Streptococcus lactis, an as yet not classified Streptococcus of the serological group D and Hafnia alvei were isolated from the third part of the mid-gut.

Die ringoffnende Polymerisation des Cyclopentens mit metallorganischen Mischkatalysatoren auf Basis von Ta- und W-Verbindungen wird ausfurlich beschrieben. Cokatalysatoren verbessern die Wirksamkeit der Mischkatalysatoren entscheidend. Losliche und in Losung stabile Wolframverbindungen vom Typ WCl5OR und WCL4 (OR)2 ergeben in Verbindung mit Alkylaluminiumverbindungen sehr wirksame Katalysatoren, einen gut reproduzierbaren Polymerisationsablauf und benotigen keine Cokatalysatoren. Wolframhaltige Mischkatalysatoren bewirken abhangig von ihrer Zusammensetzung einen Umbau bereits gebildeter Polymermolekule. Der Einflus von Fremdolefinen auf die Polymerisation gibt wichtige Hinweise auf den Mechanismus. Die Kautschuk-Eigenschaften konnen durch die Katalysatorzusammensetzung, durch Fremdolefine und durch Modifizierung des Katalysators mit geringen Mengen H2O gezielt verandert werden. Trans-Polypentenamer ist noch bei hohem Molekulargewicht leicht verarbeitbar. Die unvulkanisierten Mischungen zeigen eine hohe Festigkeit und gute Konfektionsklebrigkeit. Diese Eigenschaften bleiben auch bei Zusatz erheblicher Mengen Rus und Ol weitgehend erhalten. Auch bei niedriger Dosierung von Vernetzungsmitteln erhalt man hochelastische, alterungsbestandige und abriebfeste Vulkanisate. The ring-opening polymerization of cyclopentene by using organometallic catalysts composed of tantalum or tungsten compounds and alkylaluminium compounds is described in detail. The activity of these catalysts is definitely improved by cotalysts. Soluble tungsten compounds of the type WCl5(OR) and WCL4(OR)2 which are stable in solution, give very active catalysts (in combination with alkylaluminium compounds) with a well reproducible polymerization pattern, without need of any cocatalysts. Depending on their composition tungsten containing catalysts cause rearrangement of already formed polymer molecules. Important indications on the mechanism can be derived from the influence of additional olefins on the polymerization. Either composition of the catalysts, addition of olefins, or modification of the catalysts by small amounts of water may change the properties of the rubber. Even high molecular weight trans-polypentenamer shows ease of processing. The green compounds are of high tensile strength and of good building tack. These properties are largely maintained after addition of considerable amounts of carbon black and oil. Even with low dosage of cross-linking agents highly elastic vulcanized rubbers of good resistance to aging and abrasion are obtained.

Trans-1,5-polypentenamer can be produced with a high degree of uniformity by solution polymerization using complex catalysts of the Ziegler/Natta type. The state of order of the polymer indicates a rubber with good low temperature properties and crystallization behavior similar to that of natural rubber. There is therefore a fundamental difference between this material and other synthetic rubbers of the general purpose type. Trans-1,5-polypentenamer is easy to process, can be heavily loaded, and is therefore inexpensive to compound. Even when small amounts of the crosslinking agents are used, a high cross-linking yield is obtained and this makes it possible to produce vulcanizates that are resistant to dynamical stresses. As high green strength and good tack are present simultaneously, the material is suitable for use in the tire industry, particularly in carcass production.

A new gram-positive anaerobic bacterium is described on the basis of 89 strains isolated from the intestinal tracts of red solider bugs (Pyrrhocoris apterus L.). The fermentation products of glucose are acetic acid, lactic acid, ethanol, CO2, and H2. The guanine-plus-cytosine content of the deoxyribonucleic acid is 60 to 61 mol%. The biochemical and physiological features of this organism distinquish it from members of previously described genera. We propose a new genus, Coriobacterium, and a new species, Coriobacterium glomerans. The type strain is C. glomerans PW2 (= DSM 20642).