Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1021/acs.est.2c09573
Licence creative commons licence
Title (Primary) Functional redundancy secures resilience of chain elongation communities upon pH shifts in closed bioreactor ecosystems
Author Liu, B.; Sträuber, H.; Centler, F.; Harms, H.; Nunes da Rocha, U.; Kleinsteuber, S. ORCID logo
Source Titel Environmental Science & Technology
Year 2023
Department UMB
Volume 57
Issue 46
Page From 18350
Page To 18361
Language englisch
Topic T7 Bioeconomy
Keywords carboxylate platform; medium-chain carboxylates; lactate-based chain elongation; reactor microbiome; time series analysis; compositional data
Abstract For anaerobic mixed cultures performing microbial chain elongation, it is unclear how pH alterations affect the abundance of key players, microbial interactions, and community functioning in terms of medium-chain carboxylate yields. We explored pH effects on mixed cultures enriched in continuous anaerobic bioreactors representing closed model ecosystems. Gradual pH increase from 5.5 to 6.5 induced dramatic shifts in community composition, whereas product range and yields returned to previous states after transient fluctuations. To understand community responses to pH perturbations over long-term reactor operation, we applied Aitchison PCA clustering, linear mixed-effects models, and random forest classification on 16S rRNA gene amplicon sequencing and process data. Different pH preferences of two key chain elongation species─one Clostridium IV species related to Ruminococcaceae bacterium CPB6 and one Clostridium sensu stricto species related to Clostridium luticellarii─were determined. Network analysis revealed positive correlations of Clostridium IV with lactic acid bacteria, which switched from Olsenella to Lactobacillus along the pH increase, illustrating the plasticity of the food web in chain elongation communities. Despite long-term cultivation in closed systems over the pH shift experiment, the communities retained functional redundancy in fermentation pathways, reflected by the emergence of rare species and concomitant recovery of chain elongation functions.
Persistent UFZ Identifier
Liu, B., Sträuber, H., Centler, F., Harms, H., Nunes da Rocha, U., Kleinsteuber, S. (2023):
Functional redundancy secures resilience of chain elongation communities upon pH shifts in closed bioreactor ecosystems
Environ. Sci. Technol. 57 (46), 18350 - 18361 10.1021/acs.est.2c09573