Selective enrichment culture techniques were employed to obtain mixed cultures of methanogenic rods and sarcina from surface flooding waters and deep subsurface (-1650 m) oil-bearing sedimentary rocks and formation waters sampled from an old oil field in the U.S.S.R. previously reported to display active biological methanogenesis. The methanogens were selectively isolated as colonies on agar petri dishes that were incubated in a novel container. The general cellular and growth features of three Methanobacterium isolates were determined. These strains grew optimally at 37 to 45°C in anaerobic pressure tube cultures with a doubling time of 16 to 18 h on H2-CO2 and proliferated as autotrophs. Acetate addition significantly enhanced the final cell yield. Growth of these strains was completely inhibited by either 0.6 g of sodium sulfide per liter or 31.0 of sodium chloride per liter, but growth was not inhibited by either 0.3 g of sodium sulfide per liter or 1.0 g of sodium sulfate per liter. One novel isolate, Methanobacterium sp. strain ivanov, was grown on H2-CO2, and the stable-carbon isotopic fractionations that occurred during synthesis of methane, cell carbon, and lipids were determined. The results of this study were used to examine the anomalous relationship between the isotopic and chemical compositions of natural gas occurring in the deep subsurface environment of the oil field.

Control mice and those treated with cortisone were exposed to aerosols of viable spores of Aspergillus flavus. Fifteen to 20 minutes later, animals were killed, and alveolar macrophages were obtained by tracheobronchial lavage. Electron-microscopic examination of these cells revealed that, whereas the lysosomes of control macrophages showed extensive attraction and fusion with the phagocytic membranes surrounding spores, the lysosomes of macrophages from animals treated with cortisone revealed little, if any, interaction. This diminished lysosomal response in forming phagocytic vacuoles may be important in the subsequent development of hyphal bronchopneumonia which frequently, occurs in cortisonetreated mice exposed to spores of A. flavus.

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