Enhanced 1,3-propanediol production by supply of organic acids and repeated fed-batch culture

Abstract

In fed-batch culture of Klebsiella pneumoniae, 1,3-propanediol production was growth associated, while the by-products, including lactic acid and ethanol, increased sharply as the cells grew slowly. When the fed-batch culture was supplied with a mixture of organic acids including citrate, fumarate and succinate, cell growth and 1,3-propanediol production increased significantly, whereas the by-products, especially lactic acid and ethanol, decreased sharply. High concentrations of PDO and acetate inhibited cell growth and PDO production. To improve the PDO production, repeated fed-batch culture with addition of the organic acid mixture was performed in a 5-l reactor. The fed-batch culture was repeated five times, and the 1,3-propanediol yield and concentration reached above 0.61 mol mol(-1) and 66 g l(-1), respectively, in 20 h for each cycle. Furthermore, the PDO productivity reached above 3.30 g l(-1) h(-1) in each cycle, which was much higher than that of the original fed-batch culture.

Enhance 1,3-propanediol production from crude glycerol in batch and fed-batch fermentation with two-phase pH-controlled strategy

“…However, the dependence of growth on acetate formation can be attributed to ATP formation in the acetate formation pathway, and growth favours reactivation of inactivated glycerol dehydratase in 3-HPA production (Xue et al 2010). In this pathway, acetic acid concentration over 7.6 g l -1 caused a 50% reduction in the growth and no growth occurred when the acetate concentration exceeded 15 g l -1 at pH 6.8.…”

“…Fed-batch fermentation of K. pneumoniae SU6 were performed in 5L stirred-tank fermentors containing 2L of the fermentation medium at 37ºC and 150 rpm agitation speed. pH was controlled using twophase strategies at pH 7.5 until glycerol concentration was lower than 15-25 g l -1 (Xue et al 2010), then changed to control at pH 6.5 using 5M KOH. The optimum initial glycerol concentration from batch culture was used in this study.…”

“…Production of 1,3-PD from glycerol using chemical method has several disadvantages, such as the requirement of high pressure and temperature for the chemical reaction, the use of toxic organic solvents, and gave low yields (5-15% w/w). Therefore, its microbial process is more interesting using several bacterial strains such as Citrobacter freundii (Homann et al 1990), Clostridium butyricum (Papanikolaou et al 2004), Enterobacter agglomerans (Barbirato et al 1997) and Klebsiella pneumoniae (Chen et al 2003;Cheng et al 2004;Xiu et al 2004;Mu et al 2008;Xue et al 2010), Klebsiella oxytoca (Yang et al 2007). Among these microorganisms, K. pneumoniae is of particular interest due to its flexible regulation of the carbon and reducing equivalent fluxes under different conditions (Zeng et al 1993) as well as its higher product yield and productivity compared to other strains (Hao et al 2008).…”

“…Several strategies have been developed to increase the concentration, yield and productivity of 1,3-PD especially the fed-batch process in which the addition of substrate is controlled to achieve a high cell density and high product formation by avoiding substrate inhibition (Huang et al 2002;Mu et al 2006;Zhang et al 2007;Jun et al 2009;Zhang et al 2009;Xue et al 2010). Although there are numerous reports demonstrating a high production of 1,3-PD using fed-batch fermentations, only few reports have evaluated the feasibility of using crude glycerol from biodiesel plant as a substrate for 1,3-PD production from Klebsiella species.…”

Chemometric modeling and two-dimensional fluorescence analysis of bioprocess with a new strain of Klebsiella pneumoniae to convert residual glycerol into 1,3-propanediol

“…This chemical has acquired industrial importance in recent years because of its wide range of applications, such as in the synthesis of polyesters, polyethers, and polyurethanes [15,16]. The production of 1,3-PD by K. pneumoniae has been reported in several works, most of which use pure glycerol as the carbon source for cell growth and product synthesis [17][18][19][20].…”