摘要:

Finely ground particles (pyrite ore, uranium‐bearing quartzite, fluorapatite, sea sand, pulverized quartz, and glass beads) retarded iron oxidation in cultures ofThiobacillus ferrooxidansgrowing at pH 1.5. The inhibition was dependent on the shaking of the culture flasks and was less pronounced in static cultures. Experiments with finely ground particles indicated that the inhibition was related to the concentration and size of the particles present in the culture solution. Fluorapatite was anomalous because below 2% (w/v) it completely prevented iron oxidation but had little or no effect at higher concentrations.

ISSN:0149-0451    

DOI:10.1080/01490458009377746

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

An experimental model of chemical stratification in certain saline lakes by hydrate deposition and hydrate‐anhydrate phase transition was developed for the system sodium carbonate‐sodium sulfate‐sodium chloride. Mirabilite (Na2SO4• 10H2O) was the test hydrate. A population of an halotolerantEctothiorhodospirafrom Owens Lake, Calif., partitioned between brine and mirabilite upon decreased temperature, survived 100 days dark storage at 15°C equally well in the resulting liquid phase and in the mirabilite. The entrapped organisms did not survive the phase transition of mirabilite to thenardite, the anhydrate. Since the optimum water activity (a10) for this organism was 0.95, those remaining in the liquid phase benefitted by an increase ina10from 0.93 in the initial brine to 0.95 upon deposition of the hydrate. The “blebs of microorganisms”; reported to be included in hydrates of ancient Searles Lake, Calif., facies may have been formed contemporaneously with deposition of the salts. Implications for biogeochemical cycles of carbon and sulfur are discussed.

ISSN:0149-0451    

DOI:10.1080/01490458009377747

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The manganese‐precipitating activities of a marine bacillus (strain SG‐1) are enhanced by interaction with solid surfaces. When not attached to surfaces, SG‐1 exhibits little or no ability to oxidize manganese. After the bacteria attach to any of a variety of surfaces (e.g., glass beads, frosted glass, sand grains; and calcite crystals), manganese is rapidly precipitated and removed from solution. Attached and manganese‐precipitating cells are morphologically distinct from free‐swimming or non‐precipitating cells.

ISSN:0149-0451    

DOI:10.1080/01490458009377748

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The fine structure of iron deposits produced byLeptothrixspp. from two caverns and a surface spring were observed. In the case ofLeptothrix pseudovacuolata,the iron occurred as an amorphous deposit within the cell sheath and the cells contained gas vesicles. In the case of the otherLeptothrixspp., the iron was deposited within the cell sheath either as a hexagonal or fibrillar matrix. In the case of fibrillar iron deposits, fibrils resembling those of the sheath were found within the cytoplasm of the cells. This suggests that the deposition of iron could have occurred within the cells as well as at the cell surface. In some cases, the fine structure of microbial iron deposits could provide a means of distinguishing biological from abiological iron deposition.

ISSN:0149-0451    

DOI:10.1080/01490458009377749

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Desulfovibrio vulgariswas shown to be capable of utilizing a BaSO4precipitate as a sulfate source. The δ34S values of the evolved sulfide ranged from –4.8‰ to +6.2‰ with respect to the BaSO4and appeared to depend upon the amount of dissolved sulfate (>10–5M) present at any given time.

ISSN:0149-0451    

DOI:10.1080/01490458009377750

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Calcite precipitation occurs when trimethylamino‐N‐oxide and medium are added to surface waters collected above Lodestone and Keeper Reefs of the Great Barrier Reef. The calcium content of the water was initially 430 ppm. After 30 days incubation at 28 °C, the pH had risen and only 90 ppm of calcium remained in solution. The precipitate was analyzed by X‐ray diffraction and was found to be calcite.

ISSN:0149-0451    

DOI:10.1080/01490458009377751

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The origin of hydrogen sulfide in southeastern Montana groundwaters was investigated. Sulfate‐reducing bacteria were detected in 25 of 26 groundwater samples in numbers ranging from 2.0 × 101to greater than 2.4 × 104bacteria per 100 ml. Stable sulfur isotope fractionation studies indicated a biological role in sulfate reduction. However, sulfate‐reducing activity as determined by use of a radioactive sulfur isotope was observed in only 1 of 16 samples. It is postulated that bacterial dissimilatory sulfate reduction is responsible for a major portion of the sulfide produced in these groundwaters and that these bacteria are most likely active in the adsorbed state, possibly in subsurface microzones where environmental conditions are conducive to sulfate reduction.

ISSN:0149-0451    

DOI:10.1080/01490458009377752

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0149-0451    

DOI:10.1080/01490458009377745

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor