Team:TMU-Tokyo/Project

Abstract

Formaldehyde is a common harmful chemical, and it has a bad effect in relatively low concentration. (For example, in agricultural chemicals, in disinfectant at hospitals and in paint of building materials) Also, since fromaldehyde is mass-produced in factories, it is highly possible to exceed over the permissible amount in the environment. These days, in Japan, the detection of formaldehyde in Tone river became an issue.(1)

DEVICE1;

Sensing formaldehyde and then producing GFP

In frmRAB operon, which origin is chromosome of Escherichia coli, frmAB is normally repressed by frmR. But, when formaldehyde exists, frmR loses its inhibitory(2). This device is composed of frmR gene, its promoter and GFP gene.

DEVICE2;

Producing formaldehyde dehydrogenase, changing formaldehyde to formate

Escherichia coli has original formaldehyde dehydrogenase, but it depends on glutathione (existence). Instead of it, we found glutathione-independent formaldehyde dehydrogenase in Pseudomonas putida. This device is composed of its gene and constitutive promoter.

DEVICE3;

Producing formate dehydrogenase, changing formate to water and carbon dioxide

This formate dehydrogenase gene is derived from Methylobacterium extorquens. As formaldehyde dehydrogenase, Escherichia coli has similar function gene of this gene. But it has too long length to insert high copy plasmid. Escherichia coli has a gene that has the similar function as a formate dehydrogenase but it is too long to be inserted into the high copy plasmid. Therefore, we used the Methylobacterium extorquens’s one. This device is composed of its gene and constitutive promoter.

1. Tonegawa's formaldehyde levels spike ― DAILY YOMIURI ONLINE
2. Christopher D. Herring and Frederick R. Blattner. 2004. Global Transcriptional Effects of a Suppressor tRNA and the Inactivation of the Regulator frmR[PubMed]