ISSN:
1573-515X
Keywords:
crater lake
;
polythionates
;
sulfate budget
;
sulfur-oxidizing bacteria
;
Thiobacillus ssp.
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
Notes:
Abstract Sulfur-oxidizing bacteria, Thiobacillus thiooxidans, werefound in a highly acidic (pH = 1∼1.5) crater lake, Yugama,seasonally flowing streams and soil in the catchment area of thecrater. Thiobacillus ferrooxidans was also found in some ofthe streams but not in the lake itself. The lake water containsaqueous carbon dioxide, hydrogen sulfide, polythionates andelemental sulfur in suspension which are the substrates for thegrowth of the sulfur-oxidizing bacteria as no organic compoundsexcept for the microorganisms themselves were detected. Thebacteria isolated from the Yugama water preferred polythionatesin the following order: S4O6 2〉 S5O6 2〉 S6O6 2On the other hand,H2S was more rapidly consumed by the bacteria thanpolythionates which were followed by elemental sulfur. In thecase of test-tube incubation, the optimum pH of the solution forgrowth of the bacteria was between 1.0 and 1.5, and forcultivation in growth medium plates between 2.5 and 3.5. Thebacteria hardly proliferated at pH 0.5 or below. In accordancewith these characteristics of the bacteria, numbers of thebacteria in the surface Yugama crater lake water were at minimum(〈 a few cells/mL) in February and at maximum (106 cell/mL)in August. The bacterial activity changed in accordance with thesurface lake water temperature, but not necessarily with thevariations in H2S and polythionates concentrations of the lakewater. Based on the variation in sulfur isotope ratios of sulfateand experimentally determined rate of oxidation of H2S in thelake water, the sulfate production rate by the bacteria in thecatchment area and the lake were estimated to 9.5 and 8.4g/m2/day, respectively, during the period from 1988 to 1990when the volcanic activity at Yugama was at minimum. Also stream,hydrothermal, H2S-oxidated SO2 4-inputs and outputs byseepage and precipitation have been calculated as 4.1, 32, 0.56,36, and 1.2 ton/day, respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1005805100834
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