1,3-Propanediol Production by Clostridium Butyricum in Various Fed- Batch Feeding Strategies

Abstract

The aim of this study is to propose different fed-batch strategies during the fermentation of glycerol into 1,3-Propanediol, which show the influence of the initial concentration in glycerol and the feed flow on the behaviour of Clostridium butyricum. The kinetic study of the conversion of glycerol into 1,3-Propanediol by Clostridium butyricum, showed that according to the initial concentration of glycerol and feed flow, this strain displays two different metabolic behaviours. This strain directs its metabolism towards its traditional metabolic pathways (production of 1,3-Propanediol, butyric and acetic acid), when the culture was started with a high initial concentration of glycerol and was fed with a weak rate. The high initial concentration of glycerol causes a deceleration of growth rate, which led to an increase in the growth phase duration. Feeding by a weak flow allowed maintaining the cells in full growth phase by providing the necessary substrate for its growth and its maintenance and, at the same time, to avoid the glycerol accumulation in the medium. A high feed flow involved a glycerol accumulation in the culture medium, which obliged the bacterium to direct its metabolism towards the production of acetic acid in significant quantities. The growth phase always showed the same duration, yielding similar final concentrations in biomass and metabolites, an identical metabolic behaviour was observed when the culture begin with a low initial concentration of glycerol, and whatever the flow of substrate applied. This behaviour may be explained by a growth inhibition caused by the accumulation of 1,3-Propanediol in concentrations of 20-25 g/L.

Valorization of crude glycerol from the biodiesel industry to 1,3‐propanediol by Clostridium butyricum DSM 10702: Influence of pretreatment with ion exchange resins

“…Dietz and Zeng reported 70 g/L of 1,3‐PD final concentration with a mixed culture from a full‐scale biogas plant and continuous glycerol feeding (10 g/(L · h)). Product concentrations found in the current investigation were similar to those reported by Ahmed et al in fed‐batch fermentation of crude glycerol from a canola oil biodiesel factory. Crude glycerol was fed by 12 h pulses of 4.5 g/h over 50 h of fermentation time.…”

Clarification of 1,3-Propanediol Fermentation Broths by Using a Ceramic Fine UF Membrane

“…1,3-Propanediol (1,3-PD; CH 2 (CH 2 OH) 2 ), an organic compound, has gained considerable attention owing to its myriad industrial applications. Indeed, 1,3-PD is widely used as a monomer for the chemical synthesis of polyethers, polyurethanes and polyesters [1][2][3][4][5][6][7]. In addition, it is applicable in the production of different materials, such as composites, detergents, lubricants, laminates and coatings [8,9].…”

“…Since chemical synthesis of 1,3-PD is expensive and environmentally unfriendly [1,6,8,[12][13][14], many efforts have been made to investigate its production through microbiological bioconversion, which allows the use of renewable feedstock and provides no generation of toxic by-products. Glycerol, generated as a major by-product during biodiesel production, is considered the best natural substrate that can produce 1,3-PD [15].…”

“…Indeed, Crosse et al [16], in their recently published review article, have pointed out that almost 20% of all scientific papers pertaining to crude glycerol mention 1,3-PD. It has been well-documented that among the bacterial strains that can convert glycerol into 1,3-PD via hydrogenolysis possesses are: Citrobacter [3,[17][18][19][20], Klebsiella [3,12,21,22], Clostridia [1,13,23,24], Lactobacilli [8,9,[25][26][27] and Enterobacter [28,29].…”

Artificial intelligence system for enhanced automated 1,3-propanediol green biosynthesis

“…Based on the pattern confirmed in other research studies, scientists investigated different feeding rate control strategies to enhance the production of 1,3-PDO from crude glycerol in K. pneumoniae 24 and C. butyricum. 25 This is a reliable method but requires significant human resources, and is challenging when adapting to strains with different metabolic characteristics in future scale-up. By contrast, the closed-loop control strategy is based on measurements.…”