Continuous bioproduction of 1,3‐propanediol from biodiesel raw glycerol: Operation with free and immobilized cells of Clostridium butyricum DSM 10702

Abstract

This work investigates the bioproduction of 1,3‐propanediol (1,3‐PD) from biodiesel derived raw glycerol with free and immobilized cells of Clostridium butyricum DSMZ 10702. The cultures were carried out under continuous conditions in a stirred tank bioreactor with suspended cells and a fluidized‐bed bioreactor with immobilized cells. The microorganisms were immobilized by entrapment in calcium alginate gel beads. The effect of dilution rate and glycerol concentration in the feed on 1,3‐PD production was investigated for both bioreactor configurations. Results showed that 1,3‐PD concentration and glycerol uptake decreased when dilution rate increased. Maximum product concentration was similar in both bioreactors, 24.3 g/L and 20.5 g/L for suspended cells and Ca‐alginate immobilized cells, respectively, for a glycerol feed concentration of 50 g/L and a dilution rate of 0.05 h−1. The higher productivities were observed for a dilution rate of 0.15 h−1 for the suspended culture bioreactor and 0.2 h−1 for the immobilized cell bioreactor. Although maximum productivity was similar in both systems, 2.8 g 1,3‐PD/(L · h), cell immobilization was shown to be more resistant to washout at higher dilution rates.

Biosynthesis of 1,3‐propanodiol and 2,3‐butanodiol from residual glycerol in continuous cell‐immobilized Klebsiella pneumoniae bioreactors

“…In this study, the authors obtained 70 g L À1 of 1,3-PD and 16 g L À1 of 2,3-BD.Analyzing the effects of pH on the fluidized-bed reactor in this work, the results can be compared to the work of Ji et al44 who evaluated the effect of pH oscillation during fed-batch fermentations of K. pneumoniae, reporting that formation of 2,3-BD was achieved between pH 5.0 and 6.5, whereas lactic acid was produced between pH 7.1 and 8.0. In our study, when pH was controlled (7.0), it favored the production of HLat over 2,3-BD, whereas uncontrolled pH, which dropped to 5.5, inhibited the productions of EtOH and HLat, and stimulated the production of 2,3-BD.Comparing the kinetics of K. pneumoniae BLh-1 concerning the production of 1,3-PD, Loureiro-Pinto et al7 run continuous cultures in a fluidized-bed glass column reactor using Clostridium butyricum DSMZ 10702 immobilized in calcium alginate spheres, showing that 1,3-PD concentration and glycerol consumption decreased inversely to the dilution rate. The maximum product titter of 20.5 g L À1 for a glycerol concentration of 50 g L À1 and a dilution rate D = 0.05 h À1…”

“…Comparing the kinetics of K. pneumoniae BLh‐1 concerning the production of 1,3‐PD, Loureiro‐Pinto et al 7 run continuous cultures in a fluidized‐bed glass column reactor using Clostridium butyricum DSMZ 10702 immobilized in calcium alginate spheres, showing that 1,3‐PD concentration and glycerol consumption decreased inversely to the dilution rate. The maximum product titter of 20.5 g L −1 for a glycerol concentration of 50 g L −1 and a dilution rate D = 0.05 h −1 was reported, whereas the highest yields were observed at a D = 0.20 h −1 .…”

“…5 Several bioprocess technologies are being proposed based on the availability of glycerol and its potential to be used as microbial substrate (carbon source) to produce a wide range of chemicals by microorganisms. [6][7][8][9][10] Among these high added-value bioproducts obtained from glycerol are 1,3-propanediol (1,3-PD) and 2,3-butanediol (2,3-BD), which are widely used in the polymer industry. [10][11][12][13] The biotechnological production of these chemicals has been of great interest to researchers as an alternative to chemical synthesis.…”

Experimental methods in chemical engineering: Reactors—fluidized beds

“…For liquid–solids systems, bed porosity, , increases to the power with velocity, : where is a parameter and depends on particle properties, vessel diameter, and Reynolds’ terminal velocity. Applications include ion‐exchange and biological reactions with immobilized cells …”

Production of 1,3-Propanediol From Crude Glycerol: Bioprocess Design and Profitability Analysis

“…Therefore, finding alternative unit operations or fermentation methodologies could result in a more cost-efficient process. For example, the production of 1,3-PD using immobilized cells could allow the reuse of the biocatalyst, yielding more biological stability, a simplified downstream processing, and a decrease in bioreactor volumes (Loureiro-Pinto et al, 2017). Another plausible alternative could be to use non-sterile raw glycerol in the fermentation, lowering the intensity of the upstream processing (Kaeding et al, 2015).…”