Sulfate-Reducing Bacteria and Their Activities in Cyanobacterial Mats of Solar Lake (Sinai, Egypt)

AUTOR(ES)

Teske, Andreas

FONTE

American Society for Microbiology

RESUMO

The sulfate-reducing bacteria within the surface layer of the hypersaline cyanobacterial mat of Solar Lake (Sinai, Egypt) were investigated with combined microbiological, molecular, and biogeochemical approaches. The diurnally oxic surface layer contained between 106 and 107 cultivable sulfate-reducing bacteria ml−1 and showed sulfate reduction rates between 1,000 and 2,200 nmol ml−1 day−1, both in the same range as and sometimes higher than those in anaerobic deeper mat layers. In the oxic surface layer and in the mat layers below, filamentous sulfate-reducing Desulfonema bacteria were found in variable densities of 104 to 106 cells ml−1. A Desulfonema-related, diurnally migrating bacterium was detected with PCR and denaturing gradient gel electrophoresis within and below the oxic surface layer. Facultative aerobic respiration, filamentous morphology, motility, diurnal migration, and aggregate formation were the most conspicuous adaptations of Solar Lake sulfate-reducing bacteria to the mat matrix and to diurnal oxygen stress. A comparison of sulfate reduction rates within the mat and previously published photosynthesis rates showed that CO2 from sulfate reduction in the upper 5 mm accounted for 7 to 8% of the total photosynthetic CO2 demand of the mat.

Documentos Relacionados

• Electron Donors Utilized by Sulfate-Reducing Bacteria in Eutrophic Lake Sediments †
• Distribution and Diversity of Archaea Corresponding to the Limnological Cycle of a Hypersaline Stratified Lake (Solar Lake, Sinai, Egypt)
• Classification of the spore-forming sulfate-reducing bacteria.
• Analyses of Spatial Distributions of Sulfate-Reducing Bacteria and Their Activity in Aerobic Wastewater Biofilms
• HYDROGEN-UTILIZING, SULFATE-REDUCING BACTERIA IN MARINE SEDIMENTS1