ISSN:
1432-072X
Keywords:
Desulfovibrio
;
Freshwater and marine species
;
Dissimilatory sulfate reduction
;
Sulfate kinetics
;
ApparentK m andV max for sulfate uptake
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Apparent half-saturation constants (K m) and maximum uptake rates (V max) for sulfate were determined in four species ofDesulfovibrio of freshwater and marine origin using a35S-sulfate tracer technique. The lowerstK m (5 μM) was found in the freshwater speciesDesulfovibrio vulgaris (Marburg) and the highestK m (77 μM) in the marine speciesDesulfovibrio salexigens. Maximum specific rates of sulfate uptake (i.e.,V max) were proportional to the growth rates observed in batch cultures. The halophilicDesulfovibrio salexigens did not change itsK m andV max between 1 and 6,000 μM SO 4 2- , and apparently did not induce a low-affinity uptake system at high sulfate concentrations. The low half-saturation constants measured for sulfate uptake explain why high rates of bacterial sulfate reduction occur in surface sediments of freshwater lakes, and why sulfate reduction can be a quantitatively important process in anaerobic carbon mineralization in low-sulfate environments. The results shows that extremely low sulfate concentrations must occur before sulfate reduction is completely outcompeted by methanogenesis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00692713
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