BioChem - DOS

A Genetically Encoded Biosensor for Monitoring Isoprene Production in Engineered Escherichia coli

ACS Synthetic biology

Kim, Seong Keun; Kim, Seo Hyun; Subhadra, Bindu; Woo, Seung-Gyun; Rha, Eugene; Kim, Seon-Won; Kim, Haseong; Lee, Dae-Hee; Lee, Seung-Goo

<P>Isoprene is a valuable precursor for synthetic rubber and a signature product of terpenoid pathways. Here, we developed an isoprene biosensor by employing a TbuT transcriptional regulator of <I>Ralstonia pickettii</I> to express a fluorescent reporter gene in response to intracellular isoprene in engineered <I>Escherichia coli</I>. The TbuT regulator recognizes isoprene as its less-preferred effector molecule; thus, we amplified the reporter gene expression using a T7 RNA polymerase-mediated transcriptional cascade and iteratively tuned the promoter transcribing <I>tbuT</I> to improve the sensitivity for detecting isoprene. When the engineered <I>E. coli</I> cells expressed heterologous genes for isoprene biosynthesis, the intracellular isoprene was expelled and the <I>tbuT</I> transcription factor was subsequently activated, leading to <I>gfp</I> expression. The chromosomal isoprene biosensor showed a linear correlation between GFP fluorescence and intracellular isoprene concentration. Using this chromosomal isoprene biosensor, we successfully identified the highest isoprene producer among four different <I>E. coli</I> strains producing different amounts of isoprene. The isoprene biosensor presented here can enable high-throughput screening of isoprene synthases and metabolic pathways for efficient and sustainable production of bioisoprene in engineered microbes.</P><BR>[FIG OMISSION]</BR>

2018

American Chemical Society

2161-5063

7

10

pp.2379-2390

10.1021/acssynbio.8b00164.s001

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART90639255

https://doi.org/10.1021/acssynbio.8b00164.s001

isoprene; biosensor; Escherichia coli; transcription factor; TbuT; T7 RNA polymerase-mediated transcriptional cascade