Cargando…

Cell factories converting lactate and acetate to butyrate: Clostridium butyricum and microbial communities from dark fermentation bioreactors

BACKGROUND: Interactions between microorganisms during specific steps of anaerobic digestion determine metabolic pathways in bioreactors and consequently the efficiency of fermentation processes. This study focuses on conversion of lactate and acetate to butyrate by bacteria of dark fermentation. Th...

Descripción completa

Detalles Bibliográficos
Autores principales: Detman, Anna, Mielecki, Damian, Chojnacka, Aleksandra, Salamon, Agnieszka, Błaszczyk, Mieczysław K., Sikora, Anna
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6373154/
https://www.ncbi.nlm.nih.gov/pubmed/30760264
http://dx.doi.org/10.1186/s12934-019-1085-1
_version_ 1783394918595559424
author Detman, Anna
Mielecki, Damian
Chojnacka, Aleksandra
Salamon, Agnieszka
Błaszczyk, Mieczysław K.
Sikora, Anna
author_facet Detman, Anna
Mielecki, Damian
Chojnacka, Aleksandra
Salamon, Agnieszka
Błaszczyk, Mieczysław K.
Sikora, Anna
author_sort Detman, Anna
collection PubMed
description BACKGROUND: Interactions between microorganisms during specific steps of anaerobic digestion determine metabolic pathways in bioreactors and consequently the efficiency of fermentation processes. This study focuses on conversion of lactate and acetate to butyrate by bacteria of dark fermentation. The recently recognized flavin-based electron bifurcation as a mode of energy coupling by anaerobes increases our knowledge of anaerobic lactate oxidation and butyrate formation. RESULTS: Microbial communities from dark fermentation bioreactors or pure culture of Clostridium butyricum are able to convert lactate and acetate to butyrate in batch experiments. The ability of C. butyricum to transform lactate and acetate to butyrate was shown for the first time, with ethanol identified as an additional end product of this process. A search for genes encoding EtfAB complexes and their gene neighbourhood in C. butyricum and other bacteria capable of lactate and acetate conversion to butyrate as well as butyrate-producers only and the lactate oxidiser Acetobacterium woodii, revealed that the Etf complexes involved in (i) lactate oxidation and (ii) butyrate synthesis, form separate clusters. There is a more extent similarity between Etf subunits that are involved in lactate oxidation in various species (e.g. A. woodii and C. butyricum) than between the different etf gene products within the same species of butyrate producers. A scheme for the metabolic pathway of lactate and acetate transformation to butyrate in C. butyricum was constructed. CONCLUSIONS: Studies on the conversion of lactate and acetate to butyrate by microbial communities from dark fermentation bioreactors or Clostridium butyricum suggest that a phenomenon analogous to cross-feeding of lactate in gastrointestinal tract also occurs in hydrogen-yielding reactors. A scheme of lactate and acetate transformation pathway is proposed, based on the example of C. butyricum, which employs flavin-based electron bifurcation. This process utilizes electron-transferring flavoprotein (Etf) complexes specific for (i) lactate oxidation and (ii) butyrate formation. Phylogenetic analysis revealed that such complexes are encoded in the genomes of other bacteria capable of lactate and acetate conversion to butyrate. These findings contribute significantly to our understanding of the metabolic pathways and symbiotic interactions between bacteria during the acidogenic step of anaerobic digestion.
format Online
Article
Text
id pubmed-6373154
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-63731542019-02-25 Cell factories converting lactate and acetate to butyrate: Clostridium butyricum and microbial communities from dark fermentation bioreactors Detman, Anna Mielecki, Damian Chojnacka, Aleksandra Salamon, Agnieszka Błaszczyk, Mieczysław K. Sikora, Anna Microb Cell Fact Research BACKGROUND: Interactions between microorganisms during specific steps of anaerobic digestion determine metabolic pathways in bioreactors and consequently the efficiency of fermentation processes. This study focuses on conversion of lactate and acetate to butyrate by bacteria of dark fermentation. The recently recognized flavin-based electron bifurcation as a mode of energy coupling by anaerobes increases our knowledge of anaerobic lactate oxidation and butyrate formation. RESULTS: Microbial communities from dark fermentation bioreactors or pure culture of Clostridium butyricum are able to convert lactate and acetate to butyrate in batch experiments. The ability of C. butyricum to transform lactate and acetate to butyrate was shown for the first time, with ethanol identified as an additional end product of this process. A search for genes encoding EtfAB complexes and their gene neighbourhood in C. butyricum and other bacteria capable of lactate and acetate conversion to butyrate as well as butyrate-producers only and the lactate oxidiser Acetobacterium woodii, revealed that the Etf complexes involved in (i) lactate oxidation and (ii) butyrate synthesis, form separate clusters. There is a more extent similarity between Etf subunits that are involved in lactate oxidation in various species (e.g. A. woodii and C. butyricum) than between the different etf gene products within the same species of butyrate producers. A scheme for the metabolic pathway of lactate and acetate transformation to butyrate in C. butyricum was constructed. CONCLUSIONS: Studies on the conversion of lactate and acetate to butyrate by microbial communities from dark fermentation bioreactors or Clostridium butyricum suggest that a phenomenon analogous to cross-feeding of lactate in gastrointestinal tract also occurs in hydrogen-yielding reactors. A scheme of lactate and acetate transformation pathway is proposed, based on the example of C. butyricum, which employs flavin-based electron bifurcation. This process utilizes electron-transferring flavoprotein (Etf) complexes specific for (i) lactate oxidation and (ii) butyrate formation. Phylogenetic analysis revealed that such complexes are encoded in the genomes of other bacteria capable of lactate and acetate conversion to butyrate. These findings contribute significantly to our understanding of the metabolic pathways and symbiotic interactions between bacteria during the acidogenic step of anaerobic digestion. BioMed Central 2019-02-13 /pmc/articles/PMC6373154/ /pubmed/30760264 http://dx.doi.org/10.1186/s12934-019-1085-1 Text en © The Author(s) 2019 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Detman, Anna
Mielecki, Damian
Chojnacka, Aleksandra
Salamon, Agnieszka
Błaszczyk, Mieczysław K.
Sikora, Anna
Cell factories converting lactate and acetate to butyrate: Clostridium butyricum and microbial communities from dark fermentation bioreactors
title Cell factories converting lactate and acetate to butyrate: Clostridium butyricum and microbial communities from dark fermentation bioreactors
title_full Cell factories converting lactate and acetate to butyrate: Clostridium butyricum and microbial communities from dark fermentation bioreactors
title_fullStr Cell factories converting lactate and acetate to butyrate: Clostridium butyricum and microbial communities from dark fermentation bioreactors
title_full_unstemmed Cell factories converting lactate and acetate to butyrate: Clostridium butyricum and microbial communities from dark fermentation bioreactors
title_short Cell factories converting lactate and acetate to butyrate: Clostridium butyricum and microbial communities from dark fermentation bioreactors
title_sort cell factories converting lactate and acetate to butyrate: clostridium butyricum and microbial communities from dark fermentation bioreactors
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6373154/
https://www.ncbi.nlm.nih.gov/pubmed/30760264
http://dx.doi.org/10.1186/s12934-019-1085-1
work_keys_str_mv AT detmananna cellfactoriesconvertinglactateandacetatetobutyrateclostridiumbutyricumandmicrobialcommunitiesfromdarkfermentationbioreactors
AT mieleckidamian cellfactoriesconvertinglactateandacetatetobutyrateclostridiumbutyricumandmicrobialcommunitiesfromdarkfermentationbioreactors
AT chojnackaaleksandra cellfactoriesconvertinglactateandacetatetobutyrateclostridiumbutyricumandmicrobialcommunitiesfromdarkfermentationbioreactors
AT salamonagnieszka cellfactoriesconvertinglactateandacetatetobutyrateclostridiumbutyricumandmicrobialcommunitiesfromdarkfermentationbioreactors
AT błaszczykmieczysławk cellfactoriesconvertinglactateandacetatetobutyrateclostridiumbutyricumandmicrobialcommunitiesfromdarkfermentationbioreactors
AT sikoraanna cellfactoriesconvertinglactateandacetatetobutyrateclostridiumbutyricumandmicrobialcommunitiesfromdarkfermentationbioreactors