TY - JOUR
T1 - Increased production of L-serine in Escherichia coli through Adaptive Laboratory Evolution
AU - Mundhada, Hemanshu
AU - Seoane, Jose Miguel
AU - Schneider, Konstantin
AU - Koza, Anna
AU - Christensen, Hanne Bjerre
AU - Klein, Tobias
AU - Phaneuf, Patrick Victor
AU - Herrgard, Markus
AU - Feist, Adam
AU - Nielsen, Alex Toftgaard
PY - 2017
Y1 - 2017
N2 - L-serine is a promising building block biochemical with a high theoretical production yield from glucose. Toxicity of L-serine is however prohibitive for high-titer production in E. coli. Here, E. coli lacking L-serine degradation pathways was evolved for improved tolerance by gradually increasing L-serine concentration from 3 to 100 g/L using adaptive laboratory evolution (ALE). Genome sequencing of isolated clones revealed multiplication of genetic regions, as well as mutations in thrA, thereby showing a potential mechanism of serine inhibition. Other mutations were evaluated by MAGE combined with amplicon sequencing, revealing role of rho, lrp, pykF, eno, and rpoB on tolerance and fitness in minimal medium. Production using the tolerant strains resulted in 37 g/L of L-serine with a 24% mass yield. The resulting titer is similar to the highest production reported for any organism thereby highlighting the potential of ALE for industrial biotechnology.
AB - L-serine is a promising building block biochemical with a high theoretical production yield from glucose. Toxicity of L-serine is however prohibitive for high-titer production in E. coli. Here, E. coli lacking L-serine degradation pathways was evolved for improved tolerance by gradually increasing L-serine concentration from 3 to 100 g/L using adaptive laboratory evolution (ALE). Genome sequencing of isolated clones revealed multiplication of genetic regions, as well as mutations in thrA, thereby showing a potential mechanism of serine inhibition. Other mutations were evaluated by MAGE combined with amplicon sequencing, revealing role of rho, lrp, pykF, eno, and rpoB on tolerance and fitness in minimal medium. Production using the tolerant strains resulted in 37 g/L of L-serine with a 24% mass yield. The resulting titer is similar to the highest production reported for any organism thereby highlighting the potential of ALE for industrial biotechnology.
U2 - 10.1016/j.ymben.2016.11.008
DO - 10.1016/j.ymben.2016.11.008
M3 - Journal article
C2 - 27908688
SN - 1096-7176
VL - 39
SP - 141
EP - 150
JO - Metabolic Engineering
JF - Metabolic Engineering
ER -