AUTHOR=Tiwari Rameshwar , Sathesh-Prabu Chandran , Lee Sung Kuk 

TITLE=Bioproduction of propionic acid using levulinic acid by engineered Pseudomonas putida

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2022.939248

DOI=10.3389/fbioe.2022.939248

ISSN=2296-4185

ABSTRACT=<p>The present study elaborates on the propionic acid (PA) production by the well-known microbial cell factory <italic>Pseudomonas putida</italic> EM42 and its capacity to utilize biomass-derived levulinic acid (LA). Primarily, the <italic>P. putida</italic> EM42 strain was engineered to produce PA by deleting the methylcitrate synthase (PrpC) and propionyl-CoA synthase (PrpE) genes. Subsequently, a LA-inducible expression system was employed to express <italic>yciA</italic> (encoding thioesterase) from <italic>Haemophilus influenzae</italic> and <italic>ygfH</italic> (encoding propionyl-CoA: succinate CoA transferase) from <italic>Escherichia coli</italic> to improve the PA production by up to 10-fold under flask scale cultivation. The engineered <italic>P. putida</italic> EM42:ΔCE:<italic>yciA:ygfH</italic> was used to optimize the bioprocess to further improve the PA production titer. Moreover, the fed-batch fermentation performed under optimized conditions in a 5 L bioreactor resulted in the titer, productivity, and molar yield for PA production of 26.8 g/L, 0.3 g/L/h, and 83%, respectively. This study, thus, successfully explored the LA catabolic pathway of <italic>P. putida</italic> as an alternative route for the sustainable and industrial production of PA from LA.</p>