Homolactic Acid Fermentation by the Genetically Engineered Thermophilic Homoacetogen Moorella thermoacetica ATCC 39073.
For the efficient production of target metabolites from carbohydrates, syngas, or H2-CO2by genetically engineeredMoorella thermoacetica, the control of acetate production (a main metabolite ofM. thermoacetica) is desired. Although propanediol utilization protein (PduL) was predicted to be a phosphotransacetylase (PTA) involved in acetate production inM. thermoacetica, this has not been confirmed. Our findings described herein directly demonstrate that two putative PduL proteins, encoded by Moth_0864 (pduL1) and Moth_1181 (pduL2), are involved in acetate formation as PTAs. To disrupt these genes, we replaced each gene with a lactate dehydrogenase gene fromThermoanaerobacter pseudethanolicusATCC 33223 (T-ldh). The acetate production from fructose as the sole carbon source by thepduL1deletion mutant was not deficient, whereas the disruption ofpduL2significantly decreased the acetate yield to approximately one-third that of the wild-type strain. The double-deletion (bothpduLgenes) mutant did not produce acetate but produced only lactate as the end product from fructose. These results suggest that bothpduLgenes are associated with acetate formation via acetyl-coenzyme A (acetyl-CoA) and that their disruption enables a shift in the homoacetic pathway to the genetically synthesized homolactic pathway via pyruvate.IMPORTANCEThis is the first report, to our knowledge, on the experimental identification of PTA genes inM. thermoaceticaand the shift of the native homoacetic pathway to the genetically synthesized homolactic pathway by their disruption on a sugar platform.
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.|CREST, JST, Kawaguchi, Saitama, Japan.
Yuki
Y
Iwasaki
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.|CREST, JST, Kawaguchi, Saitama, Japan.
Akihisa
A
Kita
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.
Koichiro
K
Yoshida
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.|CREST, JST, Kawaguchi, Saitama, Japan.
Takahisa
T
Tajima
Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology, Higashi-Hiroshima, Hiroshima, Japan.
Shinichi
S
Yano
Chiba Technology Center, Research & Development Headquarters, Mitsui Engineering & Shipbuilding Co., Ltd., Ichihara-City, Chiba, Japan.
Tomohiro
T
Shou
Chiba Technology Center, Research & Development Headquarters, Mitsui Engineering & Shipbuilding Co., Ltd., Ichihara-City, Chiba, Japan.
Masahiro
M
Saito
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.
Junichi
J
Kato
Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology, Higashi-Hiroshima, Hiroshima, Japan.
Katsuji
K
Murakami
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan nyutaka@hiroshima-u.ac.jp.|CREST, JST, Kawaguchi, Saitama, Japan.
Yutaka
http://orcid.org/0000-0002-7452-7433
Y
Nakashimada
D000085:Acetates / Q000378:metabolism*; D000105:Acetyl Coenzyme A / Q000378:metabolism; D000693:Anaerobiosis; D002244:Carbon / Q000378:metabolism; D005285:Fermentation; D005818:Genetic Engineering; D007770:L-Lactate Dehydrogenase / Q000235:genetics; D058845:Moorella / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D010709:Phosphate Acetyltransferase / Q000378:metabolism; D011409:Propylene Glycols / Q000378:metabolism; D046968:Thermoanaerobacter / Q000235:genetics
D000085:Acetates; D011409:Propylene Glycols; D000105:Acetyl Coenzyme A; D002244:Carbon; D007770:L-Lactate Dehydrogenase; D010709:Phosphate Acetyltransferase
Moorella; acetogen; biomass; fermentation; sugar; syngas; thermophilic; transformation