Batch assays for biological sulfate-reduction: a review towards a standardized protocol

Abstract

Biological sulfate reduction is an established method leading to new biotechnologies in wastewater treatment. Batch assays are a powerful tool to support sulfate-reducing bacteria (SRB) research and application; however, their methodology is far from been standardized. The present review critically analyses the experimental conditions used for SRB batch assays in literature, to propose a general experimental framework supporting a future standardized protocol. Batch assays using SRB biomass (SRB-test) were grouped in three different categories depending on their objective: (1) test assessing activity of a SRB culture, (2) test determining the reduction potential of an electron donor, and (3) test determining the feasibility of using different sulfate sources as electron acceptor. Considering the methodologies and results from the reviewed publications, set-up and monitoring conditions are recommended to enhance SRB-tests comparability and reproducibility. The recommendations include the use of lactate as electron donor and sodium sulfate as electron acceptor as controls in the SRB-tests. Finally, due to the difficulty to standardize the biomass source, the microbial characterization of the biomass is recommended.

Keywords:

• Biological sulfate reduction
• sulfate reducing barceria (SRB)
• methodology
• electron donor
• electron acceptor
• acid mine drainage

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

Antonio Serrano and Denys K. Villa-Gomez are thankful to the University of Queensland for funding this research through the UQ ECR grant program (UQECR1945969 and UQECR 1946429). Sergi Astals-Garcia is grateful to the Australian Research Council for his DECRA fellowship (DE170100497) and the Spanish Ministry of Science, Innovation, and Universities for his Ramón y Cajal fellowship (RYC-2017-22372).