Gas-Phase Bioproduction of a High-Value-Added Monoterpenoid (E)-Geranic Acid by Metabolically Engineered Acinetobacter Sp. Tol 5

04 October 2019, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

Gas-phase bioproduction, in which immobilized biocatalysts are employed and chemical reactions are performed in a gas phase, has attracted researchers’ attention as a green process. However, there is difficulty in the employment of whole cell catalysts for gas-phase bioproduction due to the lack of a suitable cell immobilization method. Acinetobacter sp. Tol 5 is a unique bacterium, which is remarkably sticky and can be easily immobilized onto various material surfaces through the adhesive bacterionanofiber protein AtaA. In this study, we demonstrate the gas-phase bioproduction of (E)-geranic acid (GA), a high-value-added monoterpenoid, from geraniol using immobilized Tol 5 transformant cells, into which a gene involved in a (E)-GA synthetic pathway was introduced. Time course analysis of the liquid-phase bioproduction of (E)-GA revealed the inherent metabolism of Tol 5 involved in the degradation of (E)-GA. By disrupting the fadD4-ortholog gene, which encodes a key enzyme of the (E)-GA degradation, we successfully generated a (E)-GA-accumulating strain, Tol 5 ΔfadD4 (pGeoA). The immobilized cells of this mutant strain on a polyurethane support enabled the production of (E)-GA with a passive supply of gaseous geraniol in a batch gas-phase reaction. A major fraction of the (E)-GA, which was produced, was adsorbed onto the polyurethane support but easily extracted into ethanol, a safe solvent without environmental impact. This is the first example of gas-phase bioproduction of a complex and high-value-added compound. Tol 5 is a highly promising platform for gas-phase bioproduction.

Keywords

gas-phase bioproduction
whole cell biocatalyst
monoterpenoid
green process

Supplementary materials

Title
Description
Actions
Title
Usami et al text 191002 ESI AU
Description
Actions

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.