Comparison of microbial communities in different sulfur-based autotrophic denitrification reactors

Area of Science:

• Environmental microbiology
• Water quality management

Background:

• Sulfur-based autotrophic denitrification is crucial for mitigating eutrophication in aquatic ecosystems.
• Understanding the microbial communities involved is essential for optimizing these processes.

Purpose of the Study:

• To identify and characterize bacterial communities in sulfur-based autotrophic denitrification reactors.
• To investigate how different electron donors influence microbial composition.

Main Methods:

• High-throughput sequencing of sludge samples from various denitrification reactors.
• Principal Component Analysis (PCA) for community comparison.

Main Results:

• Microbial communities differed significantly based on electron donors (thiosulfate, elemental sulfur, sulfide).
• Predominant genera included Chlorobaculum (thiosulfate), Dechloromonas (elemental sulfur), Acinetobacter (sulfide), and Janthinobacterium (heterotrophic).
• Thiobacillus was abundant across all systems, including heterotrophic reactors.

Conclusions:

• Electron donor type is a major factor shaping microbial communities in denitrification systems.
• Microbial composition is influenced by multiple factors including running conditions and sampling points.
• Further research is needed to fully elucidate the roles of identified denitrifiers.