Details

Autor(en) / Beteiligte

• Cheon, Yuna
• Kim, Jun-Seob
• Park, Jun-Bum
• Heo, Paul
• Lim, Jae Hyung
• Jung, Gyoo Yeol
• Seo, Jin-Ho
• Park, Jin Hwan
• Koo, Hyun Min
• Cho, Kwang Myung
• Park, Jin-Byung
• Ha, Suk-Jin
• Kweon, Dae-Hyuk

Titel

A biosynthetic pathway for hexanoic acid production in Kluyveromyces marxianus

Ist Teil von

• Journal of biotechnology, 2014-07, Vol.182-183, p.30-36

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2014

Quelle

MEDLINE

Beschreibungen/Notizen

• •Hexanoic acid has been used in diverse industrial applications.•A biosynthetic pathway for hexanoic acid has never been constructed in yeast.•The pathways involving 5–7 genes were constructed in K. marxianus.•AtoB-mediated chain elongation was fast, but was followed by sudden decrease.•MCT1-mediated pathway enabled a stable production of hexanoic acid. Hexanoic acid can be used for diverse industrial applications and is a precursor for fine chemistry. Although some natural microorganisms have been screened and evolved to produce hexanoic acid, the construction of an engineered biosynthetic pathway for producing hexanoic acid in yeast has not been reported. Here we constructed hexanoic acid pathways in Kluyveromyces marxianus by integrating 5 combinations of seven genes (AtoB, BktB, Crt, Hbd, MCT1, Ter, and TES1), by which random chromosomal sites of the strain are overwritten by the new genes from bacteria and yeast. One recombinant strain, H4A, which contained AtoB, BktB, Crt, Hbd, and Ter, produced 154mg/L of hexanoic acid from galactose as the sole substrate. However, the hexanoic acid produced by the H4A strain was re-assimilated during the fermentation due to the reverse activity of AtoB, which condenses two acetyl-CoAs into a single acetoacetyl-CoA. This product instability could be overcome by the replacement of AtoB with a malonyl CoA-acyl carrier protein transacylase (MCT1) from Saccharomyces cerevisiae. Our results suggest that Mct1 provides a slow but stable acetyl-CoA chain elongation pathway, whereas the AtoB-mediated route is fast but unstable. In conclusion, hexanoic acid was produced for the first time in yeast by the construction of chain elongation pathways comprising 5–7 genes in K. marxianus.