Funneling lignin-derived compounds into polyhydroxyalkanoate by Halomonas sp. Y3

Area of Science:

• Biotechnology
• Microbiology
• Biochemistry

Background:

• Biological funneling of lignin-derived compounds (LDCs) for polyhydroxyalkanoate (PHA) synthesis presents challenges.
• Developing microbial platforms for efficient LDC utilization is crucial for sustainable bioprocessing.

Purpose of the Study:

• To isolate and characterize a microbial strain capable of producing PHA from LDCs.
• To optimize fermentation conditions for enhanced PHA production from LDCs using the identified strain.

Main Methods:

• Isolation and screening of Halomonas sp. Y3 for LDC degradation and PHA production.
• Genome sequencing of Halomonas sp. Y3 to identify relevant metabolic pathways.
• Optimization of open unsterilized fermentation conditions (pH, NaCl concentration).

Main Results:

• Halomonas sp. Y3 demonstrated high degradation rates for 4-hydroxybenzoic acid (87.2%), protocatechuate (85.8%), catechol (84.7%), and vanillic acid (83.4%).
• Significant PHA concentrations were achieved, including 535.2 mg/L from 4-HBA.
• Genome analysis revealed genes involved in LDC funneling, stress response, and PHA biosynthesis.
• Open unsterilized fermentation at pH 9.0 and 60 g/L NaCl yielded aseptic conditions and improved PHA production.

Conclusions:

• Halomonas sp. Y3 is a robust candidate for LDC bioconversion into PHA.
• The identified strain and optimized conditions offer a viable strategy for black liquor valorization.
• This study advances the biological production of PHA from renewable lignin resources.