Engineering mannitol biosynthesis in Escherichia coli and Synechococcus sp. PCC 7002 using a green algal fusion protein

TY - JOUR

T1 - Engineering mannitol biosynthesis in Escherichia coli and Synechococcus sp. PCC 7002 using a green algal fusion protein

AU - Madsen, Mary Ann

AU - Semerdzhiev, Stefan

AU - Amtmann, Anna

AU - Tonon, Thierry

N1 - © 2018 American Chemical Society. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

PY - 2018/11/8

Y1 - 2018/11/8

N2 - The genetic engineering of microbial cell factories is a sustainable alternative to the chemical synthesis of organic compounds. Successful metabolic engineering often depends on manipulating several enzymes, requiring multiple transformation steps and selection markers, as well as protein assembly and efficient substrate channeling. Naturally occurring fusion genes encoding two or more enzymatic functions may offer an opportunity to simplify the engineering process and to generate ready-made protein modules, but their functionality in heterologous systems remains to be tested. Here we show that heterologous expression of a fusion enzyme from the marine alga Micromonas pusilla, comprising a mannitol-1-phosphate dehydrogenase and a mannitol-1-phosphatase, leads to synthesis of mannitol by Escherichia coli and by the cyanobacterium Synechococcus sp. PCC 7002. Neither of the heterologous systems naturally produces this sugar alcohol, which is widely used in food, pharmaceutical, medical and chemical industries. While the mannitol production rates obtained by single-gene manipulation were lower than those previously achieved after pathway optimization with multiple genes, our findings show that naturally occurring fusion proteins can offer simple building blocks for the assembly and optimization of recombinant metabolic pathways.

AB - The genetic engineering of microbial cell factories is a sustainable alternative to the chemical synthesis of organic compounds. Successful metabolic engineering often depends on manipulating several enzymes, requiring multiple transformation steps and selection markers, as well as protein assembly and efficient substrate channeling. Naturally occurring fusion genes encoding two or more enzymatic functions may offer an opportunity to simplify the engineering process and to generate ready-made protein modules, but their functionality in heterologous systems remains to be tested. Here we show that heterologous expression of a fusion enzyme from the marine alga Micromonas pusilla, comprising a mannitol-1-phosphate dehydrogenase and a mannitol-1-phosphatase, leads to synthesis of mannitol by Escherichia coli and by the cyanobacterium Synechococcus sp. PCC 7002. Neither of the heterologous systems naturally produces this sugar alcohol, which is widely used in food, pharmaceutical, medical and chemical industries. While the mannitol production rates obtained by single-gene manipulation were lower than those previously achieved after pathway optimization with multiple genes, our findings show that naturally occurring fusion proteins can offer simple building blocks for the assembly and optimization of recombinant metabolic pathways.

U2 - 10.1021/acssynbio.8b00238

DO - 10.1021/acssynbio.8b00238

M3 - Article

SN - 2161-5063

SP - 1

EP - 27

JO - ACS Synthetic Biology

JF - ACS Synthetic Biology

ER -