Investigation of the trophic relations between anaerobic microorganisms from an underground gas repository during methanol utilization

Joint cultivation of the dominant strains of acetogenic, sulfate-reducing and methanogenic microorganisms isolated from water samples of the North Stavropol underground gas storage facility (UGSF) was carried out for revealing their probable trophic relationships. It was shown that acetogenic strains Eubacterium limosum AG12 and Sporomusa sphaeroides AG8-2 growing on methanol could form a considerable pool of hydrogen, which may support development of hydrogenotrophic cultures, the methanogen Methanobacterium formicicum MG134, or the sulfate reducer Desulfovibrio desulfuricans SR12. Growth of this sulfate-reducing strain was not stimulated under joint cultivation with Methanosarcina barkeri MGZ3 on methanol, probably due to its inability to take up low hydrogen concentrations observed during methanosarcina development. The results show that acetogens in the UGSF system are the most important consumers of methanol and hydrogen and after exhaustion of the latter and switching over to methanol utilization they can supply hydrogen to other microorganisms, including methanogens and sulfate reducers. The role of methanosarcina in the UGSF increases as the hydrogen and CO₂ reserves are exhausted, and methanogenesis on methanol becomes the main way of its destruction.     

Catabolic Potential and Surfactant Activity of Halotolerant Hydrocarbon-Oxidizing Bacteria

Microbiology - The hydrocarbon-oxidizing potential, ability to synthesize biosurfactants, and resistance to ecologically significant factors were studied for the following previously isolated...     

SO2 污染油菜对桃蚜的影响

ＳＯ_２污染油菜对桃蚜的影响龚佩瑜,吴坤君,李秀珍（中国科学院动物研究所北京１０００８０）ＳＯ２是我国大气污染的主要成分,它是一种对生物影响很大的污染物。ｓｏ。曾被用作熏蒸剂来防治害虫,但只有在浓度很高时才有效。更多的观察表明,ｓｏ：污染有利于蚜虫的?..     

Dynamics of Microbial Processes in the Stratal Waters of the Romashkinskoe Oil Field

The dynamics of the microbial processes developing in parallel with the exploitation of the Romashkinskoe oil field (Tatarstan) were studied in two areas differing in the degree of stratal water freshening. Flooding of the strata, in conjunction with purposeful measures on stratal microflora activation, was shown to increase the microbial population density and activate both methanogenesis and sulfate reduction; the latter process was limited by the low sulfate concentration. Development of anaerobic processes correlated with changes in acetate concentration in the stratal water. High mineralization (over 200 g/l) inhibited the stratal water microflora even if other conditions were favorable. Isotopic analysis of the carbonate carbon showed that the bicarbonate concentration increased in the stratal water due to microbial degradation of oil hydrocarbons and further participation of the biogenic carbon dioxide in dissolution of the carbonate cement of the oil-bearing strata. In strongly desalinated stratal water, the proportion of the newly formed bicarbonate was as high as 80%.