Initial pH Conditions Shape the Microbial Community Structure of Sewage Sludge in Batch Fermentations for the Improvement of Volatile Fatty Acid Production.
Ylenia Di LetoFanny Claire CapriAntonio MineoAlida CosenzaGiuseppe GalloRosa AlduinaGiorgio ManninaPublished in: Microorganisms (2022)
Conversion of wastewater treatment plants into biorefineries is a sustainable alternative for obtaining valuable compounds, thus reducing pollutants and costs and protecting the environment and human health. Under specific operating conditions, microbial fermentative products of sewage sludge are volatile fatty acids (VFA) that can be precursors of polyhydroxyalkanoate thermoplastic polyesters. The role of various operating parameters in VFA production has yet to be elucidated. This study aimed to correlate the levels of VFA yields with prokaryotic microbiota structures of sewage sludge in two sets of batch fermentations with an initial pH of 8 and 10. The sewage sludge used to inoculate the batch fermentations was collected from a Sicilian WWTP located in Marineo (Italy) as a case study. Gas chromatography analysis revealed that initial pH 10 stimulated chemical oxygen demands (sCOD) and VFA yields (2020 mg COD/L) in comparison with initial pH 8. Characterization of the sewage sludge prokaryotic community structures-analyzed by next-generation sequencing of 16S rRNA gene amplicons-demonstrated that the improved yield of VFA paralleled the increased abundance of fermenting bacteria belonging to Proteobacteria, Bacteroidetes, Chloroflexi, and Firmicutes phyla and, conversely, the reduced abundance of VFA-degrading strains, such as archaeal methanogens.
Keyphrases
- sewage sludge
- antibiotic resistance genes
- anaerobic digestion
- microbial community
- gas chromatography
- fatty acid
- wastewater treatment
- heavy metals
- human health
- municipal solid waste
- risk assessment
- mass spectrometry
- tandem mass spectrometry
- copy number
- saccharomyces cerevisiae
- high resolution
- escherichia coli
- high resolution mass spectrometry
- mental health
- healthcare
- single cell
- genome wide
- gene expression
- solid phase extraction
- transcription factor