Culture conditions affect Lactobacillus reuteri DSM 17938 ability to perform glycerol bioconversion into 3-hydroxypropionic acid

• Published in: Journal of bioscience and bioengineering 2021-05, Vol.131 (5), p.501-508
• Main Authors: Nguyen, Thi-Lan-Phuong, Saulou-Bérion, Claire, Delettre, Jérôme, Béal, Catherine
• Format: Article
• Language: English
• Subjects: 3-Hydroxypropionic acid production yield; Bacteriology; Bioreactors; Biotechnology; Culture Techniques; Environmental culture conditions; Glycerol - metabolism; Glycerol bioconversion; Growth medium composition; Kinetics; Lactic Acid - analogs & derivatives; Lactic Acid - metabolism; Lactobacillus reuteri; Lactobacillus reuteri - growth & development; Lactobacillus reuteri - metabolism; Life Sciences; Microbiology and Parasitology; Plackett and Burman experimental design; Propylene Glycols - metabolism; Temperature
• ISSN: 1389-1723; 1347-4421
• DOI: 10.1016/j.jbiosc.2020.12.011

The platform molecule 3-hydroxypropionic acid (3-HP) can be produced using Lactobacillus reuteri through a two-step bioprocess that involves a growth phase followed by a bioconversion phase. The bioproduction is performed by resting cells that convert glycerol into 3-HP and 1,3-propanediol in fed-batch mode. This work aimed at studying the effect of the growth conditions of L. reuteri DSM 17938 during the first step, on the glycerol bioconversion into 3-HP during the second step. A Plackett and Burman design was carried out to test, in controlled bioreactors, the effect of 11 growth conditions simultaneously, at fixed bioconversion conditions. The supplementation of the growth medium with vitamin B12 and cysteine displayed a negative effect on the 3-HP bioproduction. The addition of glucose, phytone peptone, Tween 80, 1,2-propanediol and betaine in the growth medium, together with a low temperature and an optimal pH of 6.0 during the growth phase increased the bioconversion duration from 56 h to 89 h at a glycerol feeding rate of 0.5 g·h−1. A validating experiment displayed that the 3-HP titer, 3-HP production yield and 3-HP specific production rate were significantly improved by 25 %, 150 % and 61 %, respectively. •Glycerol conversion into 3-HP by resting cells was affected by 9 growth conditions.•3-HP titer increased from 11.8 to 14.7 g·L−1 thanks to the selected conditions.•3-HP specific production rate rose by 61% as compared to the initial conditions.•A 150% increase in production yield was reached with the selected growth conditions.