Kinetics of sulfate uptake by freshwater and marine species ofDesulfovibrio
- Cite this article as:
- Ingvorsen, K. & Jørgensen, B.B. Arch. Microbiol. (1984) 139: 61. doi:10.1007/BF00692713
Apparent half-saturation constants (Km) and maximum uptake rates (Vmax) for sulfate were determined in four species ofDesulfovibrio of freshwater and marine origin using a35S-sulfate tracer technique. The lowerstKm (5 μM) was found in the freshwater speciesDesulfovibrio vulgaris (Marburg) and the highestKm (77 μM) in the marine speciesDesulfovibrio salexigens. Maximum specific rates of sulfate uptake (i.e.,Vmax) were proportional to the growth rates observed in batch cultures. The halophilicDesulfovibrio salexigens did not change itsKm andVmax between 1 and 6,000 μM SO42-, 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.
Key wordsDesulfovibrioFreshwater and marine speciesDissimilatory sulfate reductionSulfate kineticsApparentKm andVmax for sulfate uptake
methane producing bacteria
sulfate reducing bacteria