Optimization of Fermentation Conditions of Glycerol to 1,3-propanediol by an Alkali-resistant Klebsiella pneumonia ZH-1 Using Response Surface Methodology (RSM)

Abstract

1,3-propanediol (1,3-PD) is an important chemical material and can be used as monomer to produce polyesters, polyethers and polyurethanes. Its biosynthetic method arouses our more and more interests. In this study, 1,3-PD was produced from crude glycerol through the fermentation of a Klebsieblla sp. ZH-1 strain isolated from a anaerobic sludge collected in Fenhe river. The fermentation condition of 1,3-propanediol from strain ZH-1 was optimized in 3 aspects of temperature, pH and inoculum by one factor at a time and response surface methodology. Results showed that the optimal fermentation parameters for temperature, pH and inoculum were determined as 36°C, 7.8 and 11%, respectively. Under these conditions, the practical yield of 1,3-PD was 19.93 g-L-1 and a molar yield (mol1,3-PD-molGlycerol-1) of 1,3-propanediol to glycerol of 0.52. Compared with other strains of producing 1,3-PD by fermentation, the strain K. pneumoniae ZH-1 has a higher molar conversion rate. Meanwhile, we believe the strain ZH-1 is an alkaline resistant strain.