Comparison of engineered Escherichia coli AF1000 and BL21 strains for (R)-3-hydroxybutyrate production in fed-batch cultivation
Perez-Zabaleta, Mariel LU
; Guevara-Martínez, Mónica
; Gustavsson, Martin
; Quillaguamán, Jorge
LU
; Larsson, Gen
and van Maris, Antonius J.A.
(2019)
In Applied Microbiology and Biotechnology
103(14).
p.5627-5639
- Abstract
Accumulation of acetate is a limiting factor in recombinant production of (R)-3-hydroxybutyrate (3HB) by Escherichia coli in high-cell-density processes. To alleviate this limitation, this study investigated two approaches: (i) deletion of phosphotransacetylase (pta), pyruvate oxidase (poxB), and/or the isocitrate lyase regulator (iclR), known to decrease acetate formation, on bioreactor cultivations designed to achieve high 3HB concentrations. (ii) Screening of different E. coli strain backgrounds (B, BL21, W, BW25113, MG1655, W3110, and AF1000) for their potential as low acetate-forming, 3HB-producing platforms. Deletion of pta and pta-poxB in the AF1000 strain background was to some extent successful in decreasing acetate formation,... (More)
Accumulation of acetate is a limiting factor in recombinant production of (R)-3-hydroxybutyrate (3HB) by Escherichia coli in high-cell-density processes. To alleviate this limitation, this study investigated two approaches: (i) deletion of phosphotransacetylase (pta), pyruvate oxidase (poxB), and/or the isocitrate lyase regulator (iclR), known to decrease acetate formation, on bioreactor cultivations designed to achieve high 3HB concentrations. (ii) Screening of different E. coli strain backgrounds (B, BL21, W, BW25113, MG1655, W3110, and AF1000) for their potential as low acetate-forming, 3HB-producing platforms. Deletion of pta and pta-poxB in the AF1000 strain background was to some extent successful in decreasing acetate formation, but also dramatically increased excretion of pyruvate and did not result in increased 3HB production in high-cell-density fed-batch cultivations. Screening of the different E. coli strains confirmed BL21 as a low acetate-forming background. Despite low 3HB titers in low-cell-density screening, 3HB-producing BL21 produced five times less acetic acid per mole of 3HB, which translated into a 2.3-fold increase in the final 3HB titer and a 3-fold higher volumetric 3HB productivity over 3HB-producing AF1000 strains in nitrogen-limited fed-batch cultivations. Consequently, the BL21 strain achieved the hitherto highest described volumetric productivity of 3HB (1.52 g L−1 h−1) and the highest 3HB concentration (16.3 g L−1) achieved by recombinant E. coli. Screening solely for 3HB titers in low-cell-density batch cultivations would not have identified the potential of this strain, reaffirming the importance of screening with the final production conditions in mind.
(Less)
- author
- Perez-Zabaleta, Mariel
LU
; Guevara-Martínez, Mónica
; Gustavsson, Martin
; Quillaguamán, Jorge
LU
; Larsson, Gen
and van Maris, Antonius J.A.
- publishing date
- 2019-07-20
- type
- Contribution to journal
- publication status
- published
- keywords
- (R)-3-hydroxybutyrate, Acetate, BL21, Escherichia coli, Fed batch, Nitrogen limitation
- in
- Applied Microbiology and Biotechnology
- volume
- 103
- issue
- 14
- pages
- 13 pages
- publisher
- Springer
- external identifiers
-
- pmid:31104101
- scopus:85066078742
- ISSN
- 0175-7598
- DOI
- 10.1007/s00253-019-09876-y
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2019, The Author(s).
- id
- 2c78b44e-8fc2-438d-bafb-3320f060406c
- date added to LUP
- 2026-02-26 11:46:04
- date last changed
- 2026-05-22 00:54:27
@article{2c78b44e-8fc2-438d-bafb-3320f060406c,
abstract = {{<p>Accumulation of acetate is a limiting factor in recombinant production of (R)-3-hydroxybutyrate (3HB) by Escherichia coli in high-cell-density processes. To alleviate this limitation, this study investigated two approaches: (i) deletion of phosphotransacetylase (pta), pyruvate oxidase (poxB), and/or the isocitrate lyase regulator (iclR), known to decrease acetate formation, on bioreactor cultivations designed to achieve high 3HB concentrations. (ii) Screening of different E. coli strain backgrounds (B, BL21, W, BW25113, MG1655, W3110, and AF1000) for their potential as low acetate-forming, 3HB-producing platforms. Deletion of pta and pta-poxB in the AF1000 strain background was to some extent successful in decreasing acetate formation, but also dramatically increased excretion of pyruvate and did not result in increased 3HB production in high-cell-density fed-batch cultivations. Screening of the different E. coli strains confirmed BL21 as a low acetate-forming background. Despite low 3HB titers in low-cell-density screening, 3HB-producing BL21 produced five times less acetic acid per mole of 3HB, which translated into a 2.3-fold increase in the final 3HB titer and a 3-fold higher volumetric 3HB productivity over 3HB-producing AF1000 strains in nitrogen-limited fed-batch cultivations. Consequently, the BL21 strain achieved the hitherto highest described volumetric productivity of 3HB (1.52 g L<sup>−1</sup> h<sup>−1</sup>) and the highest 3HB concentration (16.3 g L<sup>−1</sup>) achieved by recombinant E. coli. Screening solely for 3HB titers in low-cell-density batch cultivations would not have identified the potential of this strain, reaffirming the importance of screening with the final production conditions in mind.</p>}},
author = {{Perez-Zabaleta, Mariel and Guevara-Martínez, Mónica and Gustavsson, Martin and Quillaguamán, Jorge and Larsson, Gen and van Maris, Antonius J.A.}},
issn = {{0175-7598}},
keywords = {{(R)-3-hydroxybutyrate; Acetate; BL21; Escherichia coli; Fed batch; Nitrogen limitation}},
language = {{eng}},
month = {{07}},
number = {{14}},
pages = {{5627--5639}},
publisher = {{Springer}},
series = {{Applied Microbiology and Biotechnology}},
title = {{Comparison of engineered <i>Escherichia coli</i> AF1000 and BL21 strains for (<i>R</i>)-3-hydroxybutyrate production in fed-batch cultivation}},
url = {{http://dx.doi.org/10.1007/s00253-019-09876-y}},
doi = {{10.1007/s00253-019-09876-y}},
volume = {{103}},
year = {{2019}},
}