Metabolic engineering of Thermoanaerobacterium AK17 for increased ethanol production in seaweed hydrolysate
(2023) In Biotechnology for Biofuels and Bioproducts 16(1).- Abstract
Sustainably produced renewable biomass has the potential to replace fossil-based feedstocks, for generation of biobased fuels and chemicals of industrial interest, in biorefineries. In this context, seaweeds contain a large fraction of carbohydrates that are a promising source for enzymatic and/or microbial biorefinery conversions. The thermoanaerobe Thermoanaerobacterium AK17 is a versatile fermentative bacterium producing ethanol, acetate and lactate from various sugars. In this study, strain AK17 was engineered for more efficient production of ethanol by knocking out the lactate and acetate side-product pathways. This was successfully achieved, but the strain reverted to acetate production by recruiting enzymes from the butyrate... (More)
Sustainably produced renewable biomass has the potential to replace fossil-based feedstocks, for generation of biobased fuels and chemicals of industrial interest, in biorefineries. In this context, seaweeds contain a large fraction of carbohydrates that are a promising source for enzymatic and/or microbial biorefinery conversions. The thermoanaerobe Thermoanaerobacterium AK17 is a versatile fermentative bacterium producing ethanol, acetate and lactate from various sugars. In this study, strain AK17 was engineered for more efficient production of ethanol by knocking out the lactate and acetate side-product pathways. This was successfully achieved, but the strain reverted to acetate production by recruiting enzymes from the butyrate pathway. Subsequently this pathway was knocked out and the resultant strain AK17_M6 could produce ethanol close to the maximum theoretical yield (90%), leading to a 1.5-fold increase in production compared to the wild-type strain. Strain AK17 was also shown to successfully ferment brown seaweed hydrolysate from Laminaria digitata to ethanol in a comparatively high yield of 0.45 g/g substrate, with the primary carbon sources for the fermentations being mannitol, laminarin-derived glucose and short laminari-oligosaccharides. As strain AK17 was successfully engineered and has a wide carbohydrate utilization range that includes mannitol from brown seaweed, as well as hexoses and pentoses found in both seaweeds and lignocellulose, the new strain AK17_M6 obtained in this study is an interesting candidate for production of ethanol from both second and third generations biomass.
(Less)
- author
- organization
- publishing date
- 2023-09-11
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Biotechnology for Biofuels and Bioproducts
- volume
- 16
- issue
- 1
- article number
- 135
- pages
- 15 pages
- publisher
- BioMed Central (BMC)
- external identifiers
-
- scopus:85170650538
- pmid:37697400
- ISSN
- 2731-3654
- DOI
- 10.1186/s13068-023-02388-y
- language
- English
- LU publication?
- yes
- id
- 78f688b1-d20c-4915-b316-be7166afa970
- date added to LUP
- 2023-09-16 07:50:12
- date last changed
- 2024-04-19 01:02:14
@article{78f688b1-d20c-4915-b316-be7166afa970, abstract = {{<p>Sustainably produced renewable biomass has the potential to replace fossil-based feedstocks, for generation of biobased fuels and chemicals of industrial interest, in biorefineries. In this context, seaweeds contain a large fraction of carbohydrates that are a promising source for enzymatic and/or microbial biorefinery conversions. The thermoanaerobe Thermoanaerobacterium AK17 is a versatile fermentative bacterium producing ethanol, acetate and lactate from various sugars. In this study, strain AK17 was engineered for more efficient production of ethanol by knocking out the lactate and acetate side-product pathways. This was successfully achieved, but the strain reverted to acetate production by recruiting enzymes from the butyrate pathway. Subsequently this pathway was knocked out and the resultant strain AK17_M6 could produce ethanol close to the maximum theoretical yield (90%), leading to a 1.5-fold increase in production compared to the wild-type strain. Strain AK17 was also shown to successfully ferment brown seaweed hydrolysate from Laminaria digitata to ethanol in a comparatively high yield of 0.45 g/g substrate, with the primary carbon sources for the fermentations being mannitol, laminarin-derived glucose and short laminari-oligosaccharides. As strain AK17 was successfully engineered and has a wide carbohydrate utilization range that includes mannitol from brown seaweed, as well as hexoses and pentoses found in both seaweeds and lignocellulose, the new strain AK17_M6 obtained in this study is an interesting candidate for production of ethanol from both second and third generations biomass.</p>}}, author = {{Moenaert, Antoine and Bjornsdottir, Bryndís and Haraldsson, Einar Baldvin and Allahgholi, Leila and Zieri, Anna and Zangl, Isabella and Sigurðardóttir, Sigríður and Örlygsson, Jóhann and Nordberg Karlsson, Eva and Friðjónsson, Ólafur H and Hreggviðsson, Guðmundur Óli}}, issn = {{2731-3654}}, language = {{eng}}, month = {{09}}, number = {{1}}, publisher = {{BioMed Central (BMC)}}, series = {{Biotechnology for Biofuels and Bioproducts}}, title = {{Metabolic engineering of <i>Thermoanaerobacterium</i> AK17 for increased ethanol production in seaweed hydrolysate}}, url = {{http://dx.doi.org/10.1186/s13068-023-02388-y}}, doi = {{10.1186/s13068-023-02388-y}}, volume = {{16}}, year = {{2023}}, }