Functional consortium from aerobic granules under high organic loading rates

Area of Science:

• Environmental microbiology
• Wastewater treatment technologies
• Microbial ecology

Background:

• Aerobic sludge granules are crucial for efficient wastewater treatment.
• High organic loading rates (OLR) can destabilize microbial communities in these systems.
• Identifying key functional bacteria is vital for robust granule performance.

Purpose of the Study:

• To isolate and identify functional bacterial consortiums resilient to high organic loading rates (OLR).
• To understand the microbial dynamics underlying the stability of aerobic sludge granules under stress.
• To validate a novel method for isolating stress-tolerant microbial communities.

Main Methods:

• Cultivation of aerobic sludge granules at low OLR.
• Stepwise increase in organic loading to challenge the microbial community.
• Isolation of functional consortiums using an organic shock-loading-to-extinction approach.
• Identification of key bacterial strains within the consortium.

Main Results:

• A stable functional consortium was isolated, comprising Zoogloea resiniphila and two uncultured strains (Acinetobacter sp. clone JT2, bacterium clone P1D1-516).
• The loss of these specific uncultured strains led to protein leakage and granule destabilization.
• The organic shock-loading-to-extinction method proved effective in isolating high-OLR-tolerant consortiums.

Conclusions:

• Specific bacterial strains are critical for maintaining the structural integrity and function of aerobic sludge granules under high OLR.
• The shock-loading-to-extinction approach is a viable strategy for discovering robust microbial consortia for wastewater treatment.
• Understanding functional consortiums enhances the design of resilient biological wastewater treatment systems.