Enhanced Production of β-Nicotinamide Mononucleotide with Exogenous Nicotinamide Addition in Saccharomyces boulardii-YS01

Abstract

β-Nicotinamide mononucleotide (NMN), as a key precursor of an essential coenzyme nicotinamide adenine dinucleotide (NAD+), is most recognized for its pathological treatment effects and anti-aging functions. Here, the biosynthesis of NMN from the inexpensive feedstock substrate nicotinamide (Nam) using previously isolated Saccharomyces boulardii-YS01 was investigated. Ultra-high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UPLC-ESI-QqQ-MS/MS) was established for the determination and targeted analysis of NMN, nicotinamide riboside (NR), nicotinic acid (NA), Nam, and NAD+ in YS01 cells. Satisfactory precision and accuracy values were achieved with recoveries above 70% for five analytes. A 5~100 times higher content of NMN in YS01 (0.24~103.40 mg/kg) than in some common foods (0.0~18.8 mg/kg) was found. Combined with genome sequencing and enzyme function annotation, target-acting enzymes, including nudC, ISN1, URH1, PNP, and SIR2, were identified, and the biosynthetic pathway of NMN via Nam was suggested. The initial addition of 3 g/L Nam in the culture medium effectively promoted the generation of NMN, which raised the content of NMN by 39%. This work supplements an alternative resource for NMN production and lays the theoretical foundation for the further construction of NMN transgenic synthesis hosts.

Improvement of an enzymatic cascade synthesis of nicotinamide mononucleotide via protein engineering and reaction‐process reinforcement

“…By chemical methods, the residual enantiomeric impurities, as well as the use of toxic raw materials and solvents, have limited its application in the food and drug industry. [ 6 ] For the microbial fermentation methods, the host bacteria employed in the synthesis of NMN include Lactococcus lactis , Saccharomyces boulardii , and Escherichia coli , [ 7–9 ] and the engineering of these strains has achieved great progress for NMN synthesis. [ 10 ] However, the purification of fermentation broth is significantly complicated due to the presence of yellow‐colored pigments, presenting a formidable challenge.…”