Affiliation:
1. National Food Institute Technical University of Denmark Kongens Lyngby Denmark
2. Department of Chemistry and Bioscience Aalborg University Aalborg Denmark
3. Department of Health Technology Technical University of Denmark Kongens Lyngby Denmark
4. National Centre for Nano Fabrication and Characterization Technical University of Denmark Kongens Lyngby Denmark
5. Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon Republic of Korea
Abstract
AbstractLactococcus lactis, a lactic acid bacterium with a typical fermentative metabolism, can also use oxygen as an extracellular electron acceptor. Here we demonstrate, for the first time, that L. lactis blocked in NAD+ regeneration can use the alternative electron acceptor ferricyanide to support growth. By electrochemical analysis and characterization of strains carrying mutations in the respiratory chain, we pinpoint the essential role of the NADH dehydrogenase and 2‐amino‐3‐carboxy‐1,4‐naphtoquinone in extracellular electron transfer (EET) and uncover the underlying pathway systematically. Ferricyanide respiration has unexpected effects on L. lactis, e.g., we find that morphology is altered from the normal coccoid to a more rod shaped appearance, and that acid resistance is increased. Using adaptive laboratory evolution (ALE), we successfully enhance the capacity for EET. Whole‐genome sequencing reveals the underlying reason for the observed enhanced EET capacity to be a late‐stage blocking of menaquinone biosynthesis. The perspectives of the study are numerous, especially within food fermentation and microbiome engineering, where EET can help relieve oxidative stress, promote growth of oxygen sensitive microorganisms and play critical roles in shaping microbial communities.
Subject
Applied Microbiology and Biotechnology,Biochemistry,Bioengineering,Biotechnology
Cited by
7 articles.
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