Production of (R)-3-hydroxybutyric acid by fermentation and bioconversion processes with Azohydromonas lata

Area of Science:

• Microbiology
• Biotechnology
• Biochemistry

Background:

• Investigating microbial production of (R)-3-hydroxybutyric acid ((R)-3-HB).
• Exploring the potential of Azohydromonas lata and its mutants for (R)-3-HB synthesis.

Purpose of the Study:

• To assess the feasibility of producing (R)-3-HB using wild type and UV-induced mutant strains of Azohydromonas lata.
• To optimize (R)-3-HB production by evaluating mutant M5 with various bioconversion substrates.

Main Methods:

• UV-induced mutagenesis of Azohydromonas lata to generate mutant strains.
• Cultivation of wild type and mutant strains using sucrose as a carbon source.
• Bioconversion experiments using resting cells of mutant M5 with different substrates (glucose, ethylacetoacetate, (R,S)-1,3-butanediol).

Main Results:

• Azohydromonas lata mutant M5 produced 780 mg/l of (R)-3-HB with sucrose.
• Mutant M5 demonstrated a 2.7-fold increase in (R)-3-HB production compared to the wild type when using sucrose and (R,S)-1,3-butanediol.
• Bioconversion using resting cells of M5 yielded (R)-3-HB concentrations of 6.5 g/l (glucose), 7.3 g/l (ethylacetoacetate), and 8.7 g/l ((R,S)-1,3-butanediol).

Conclusions:

• UV-induced mutagenesis is effective in enhancing (R)-3-HB production in Azohydromonas lata.
• Mutant M5 shows significant potential for the bioconversion of various substrates into (R)-3-HB.
• Optimized bioconversion processes using mutant M5 can achieve high concentrations of (R)-3-HB.