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Characterization of...
Abstract
Ämnesord
Stäng
- Valorisation of food residues would greatly benefit from development of robust processes that create added value compared to current feed- and biogas applications. Recent advances in membrane-bioreactor-based open mixed microbial cultures, enable robust conversion of fluctuating streams of food residues to a mixture of volatile fatty acids (VFAs). In this study, such a mixed stream of VFAs was investigated as a substrate for Escherichia coli, a well-studied organism suitable for application in further conversion of the acids into compounds of higher value, and/or that are easier to separate from the aqueous medium. E. coli was cultured in batch on a VFA-rich anaerobic digest of food residues, tolerating up to 40 mM of total VFAs without any reduction in growth rate. In carbon-limited chemostats of E. coli W3110 ΔFadR on a simulated VFA mixture, the straight-chain VFAs (C2-C6) in the mixture were readily consumed simultaneously. At a dilution rate of 0.1 h−1, mainly acetic-, propionic- and caproic acid were consumed, while consumption of all the provided acids were observed at 0.05 h−1. Interestingly, also the branched isovaleric acid was consumed through a hitherto unknown mechanism. In total, up to 80% of the carbon from the supplied VFAs was consumed by the cells, and approximately 2.7% was excreted as nucleotide precursors in the medium. These results suggest that VFAs derived from food residues are a promising substrate for E. coli.
Ämnesord
- TEKNIK OCH TEKNOLOGIER -- Industriell bioteknik -- Bioprocessteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Industrial Biotechnology -- Bioprocess Technology (hsv//eng)
Nyckelord
- Anaerobic digest
- Escherichia coli
- Food waste
- VFA
- Volatile fatty acids
- acetic acid
- ammonia
- butyric acid
- carbon
- hexanoic acid
- isovaleric acid
- phosphate
- polyethersulfone
- propionic acid
- valeric acid
- volatile fatty acid
- anaerobic digestion
- Article
- bacterial growth
- biodegradation
- biomass
- carbon source
- growth rate
- metabolomics
- methanogenesis
- microbial community
- nonhuman
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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