Production of 1,3-propanediol from glycerol using a new isolate Klebsiella sp. AA405 carrying low levels of virulence factors

Abstract

Klebsiella pneumoniae is a promising industrial species for the production of chemicals, yet its opportunistic pathogenicity restrains real-world applications. In this work, we identified a novel isolate designated Klebsiella sp. AA405 which carried low levels of virulence factors. No capsule, fimbriae and flagella were observed around colonies. Genome alignment between Klebsiella sp. AA405 and other 186 Klebsiella species revealed 3421 homologous genes. Notably, the endotoxin of Klebsiella sp. AA405 was only half of E. coli BL21. This strain matched well with common cloning and expression vectors and was sensitive to antibiotics. More importantly, this strain metabolized diverse carbon sources. Under micro-aerobic conditions, it produced 51.66 g/L 1,3-propanediol, 3.82 g/L 3-hydroxypropionic acid and 6.86 g/L 2,3-butanediol in a 5 L bioreactor using glycerol as the sole carbon source. Overall these results indicate that Klebsiella sp. AA405 is a promising strain for the production of bulk chemicals.

Keywords

• Klebsiella pneumoniae
• virulence factor
• endotoxin
• 1,3-propanediol
• 2,3-butanediol