Diversity of Lactobacillus reuteri Strains in Converting Glycerol into 3-Hydroxypropionic Acid

• Published in: Applied biochemistry and biotechnology 2015-10, Vol.177 (4), p.923-939
• Main Authors: Burgé, G, Saulou-Bérion, C, Moussa, M, Pollet, B, Flourat, A, Allais, F, Athès, V, Spinnler, H.E
• Format: Article
• Language: English
• Subjects: Bacteria; Biochemistry; bioconversion; Biodiversity; Biotechnology; Biotransformation; Chemistry; Chemistry and Materials Science; Enzymatic activity; enzyme activity; glycerol; Glycerol - metabolism; Hydrogen-Ion Concentration; Kinetics; Lactic Acid - analogs & derivatives; Lactic Acid - metabolism; Lactobacillus reuteri; Lactobacillus reuteri - classification; Lactobacillus reuteri - cytology; Lactobacillus reuteri - metabolism; Life Sciences; Metabolites; physiological state; Propionates - metabolism; Species Specificity; Studies
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-015-1787-8

The present study aims at comparing the performances of three Lactobacillus reuteri strains (DSM 20016, DSM 17938, and ATCC 53608) in producing 3-hydroxypropionic acid (3-HP) from glycerol and at exploring inhibition phenomena during this bioconversion. Differences were highlighted between the three strains in terms of 3-HP production yield, kinetics of substrate consumption, and metabolite production. With a maximal productivity in non-optimal conditions (free pH) around 2 g.L⁻¹.h⁻¹ of 3-HP and 4 g.L⁻¹.h⁻¹ of 3-hydroxypropionaldehyde (3-HPA) depending on the strain, this study confirmed the potential of L. reuteri for the biotechnological production of 3-HP. Moreover, the molar ratios of 3-HP to 1,3-propanediol (1,3-PDO) obtained for the three strains (comprised between 1.25 and 1.65) showed systematically a higher 3-HP production. From these results, the DSM 17938 strain appeared to be the most promising strain. The impact of glycerol bioconversion on the bacteria’s physiological state (a decrease of around 40 % in DSM 17938 cells showing an enzymatic activity after 3 h) and survival (total loss of cultivability after 2 or 3 h depending on the strains) was revealed and discussed. The effect of each metabolite on L. reuteri DSM 17938 was further investigated, displaying a drastic inhibition caused by 3-HPA, while 3-HP induced lower impact and only at acidic pH.