Production of 3-Hydroxypropionic Acid by Engineered Kluyveromyces marxianus

Thermotolerant yeast, Kluyveromyces marxianus was applied for the production of 3-hydroxypropionic acid (3HP), which is mainly used as a raw material for biodegradable polymers. The MCR (malonyl-CoA reductase) gene originated from the Chloroflexus aurantiacus strain was introduced into the engineered K. marxianus 17555-JBP2 strain showing improved xylose utilization in the previous study to develop the engineered K. marxianus JBP2_MCR strain. At 40oC, K. marxianus JBP2_MCR strain produced 0.14±0.00 g/L of 3-HP using xylose as a sole carbon source. As a result of measuring the enzymatic activity of malonyl-CoA reductase, the engineered K. marxianus JBP2_MCR strain exhibited 4.71 times higher MCR enzymatic activity than the parent strain. When 1.28 g/L malonyl-CoA was added into media, 1.58±0.18 g/L of 3-HP was produced by K. marxianus JBP2_MCR strain for 120 h.