ISSN:0149-0451    

DOI:10.1080/01490458009377754

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

An aqueous suspension of clay, dolomite, quartz, and organic matter was sedimented through a saline solution containing trace amounts of copper and zinc and accumulated on an organic‐rich layer where sulfide was being generated by sulfate‐reducing bacteria. A control system was set up in which the organic matter was omitted and the sulfide provided by diffusion of a sodium sulfide solution from beneath the sediments. In the organic system the copper and zinc were separated and fixed in different sedimentary layers, whereas in the control system they precipitated together. Metal distributions in the former system indicated that copper forms soluble metal‐organic complexes that keep the copper in solution in the presence of sulfide. Zinc also forms metal‐organic complexes, but these are apparently not resistant to sorption and precipitation processes.

ISSN:0149-0451    

DOI:10.1080/01490458009377755

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The isotopic composition (δ15N) of nitrite produced during nitrate respiration by both growing and washed cells of the marine bacterium,Serratia marinorubra,was determined. In both the growing and washed cells, δ15N of the nitrite changed considerably with time. At least two reaction steps, producing different isotope effects (active transport of nitrate across membranes and reduction of nitrate to nitrite), appear to be involved. With washed cells, a fractionation factor as high as 1.039 was obtained—the highest ever reported for biologicalnitrate reduction. The physiological state of nitrate‐respiring bacteria in oxygen‐depleted subsurface waters of the sea is discussed from the viewpoint of isotope fractionation.

ISSN:0149-0451    

DOI:10.1080/01490458009377756

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

During the summer of 1977, a severe drought throughout the western part of the United States caused the north arm of the Great Salt Lake, Utah, to evaporate to its lowest level in a number of years, resulting in the precipitation of about 99.6% pure sodium chloride. At the extreme north end of the north arm, in the vicinity of Monument Point, low humidity combined with a shallow‐bottom gradient to form a salt crust along the lake margin in which gas‐emitting domes were common. The domes varied in size; each contained a large amount of gas that analysis showed to be 82 to 86% oxygen and 14 to 18% nitrogen, with <0.2% or no methane, and no detectable carbon dioxide. The bottom of the crust of the domes (3 to 4 cm thick) was a bright red color. Microscopic examination of this red zone revealed 3.5 × 104cells ofDunaliella salina,2 × 103cells ofD. viridisand 108to 109clumps of red halophilic bacteria per g of salt. Measurements in situ showed sufficient light (34 klx) and temperature (34°C) under the salt to favor the growth of the algae and associated bacteria within the water phase of the crust or in water immediately underneath the crust. Oxygen produced as a result of algal photosynthesis was trapped under the crust until the crust was either eroded by waves or broken under pressure, releasing the gas. The domes were not observed during the summers of 1978 and 1979.

ISSN:0149-0451    

DOI:10.1080/01490458009377757

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Bacterial cycling of sulfur at the sediment‐water interface was studied in situ at 10‐m water depth in both transparent and opaque closed‐box systems over a period of 245 days. Reducing processes dominated at Eh values below +200 mV. In the transparent systems, oxygen was produced because of photosynthesis and the redox turnover was delayed 30 days compared to the opaque systems in which reducing conditions were established in 10 days.

ISSN:0149-0451    

DOI:10.1080/01490458009377758

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A diverse, abundant, apparently procaryotic microflora is here reported from the Tyler Fm., upper Baraga Group, Gogebic County, Michigan. In addition, numerous chains of spheroids and grains of hematite after pyrite from the Baraga Group, Baraga County, suggest a microbial presence.

ISSN:0149-0451    

DOI:10.1080/01490458009377759

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The vadose zone of the Chalk aquifer from two sites of different land use was found to contain large numbers of nitrate‐reducing and ammonium‐oxidizing bacteria. Relationships between the type of bacteria and nitrogen compounds produced showed that denitrification was occurring beneath the permanent grassland site, whereas the vadose zone beneath the fertilized arable site was essentially aerobic and little attenuation of nitrate by denitrification was occurring. The results show that nitrate is certain to be involved in biological reactions in the vadose zone of the Chalk, although quantification of the rate and the extent of these reactions is still not possible.

ISSN:0149-0451    

DOI:10.1080/01490458009377760

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The Sulfate‐reducing Bacteria,J. R. Postgate. Cambridge University Press, London, UK, 1979. With 20 figures, 4 tables, viii + 151 p. $29.50

ISSN:0149-0451    

DOI:10.1080/01490458009377761

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0149-0451    

DOI:10.1080/01490458009377753

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor