Multi-production of high added market value metabolites from diluted methane emissions via methanotrophic extremophiles. (November 2018)

• Record Type: Journal Article
• Authors: Cantera, S.; Sánchez-Andrea, I.; Lebrero, R.; García-Encina, P.A.; Stams, Alfons J.M.; Muñoz, R.
• Is Part Of: Bioresource technology. Volume 267(2018)
• Page Start: 401
• Page End: 407
• Publication Date: 2018-11
• Subjects: CH4-biorefinery -- Ectoine -- Exopolysaccharides -- Hydroxyectoine -- Methane abatement; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2018.07.057
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Innovative process of CH4 bioconversion into ectoine, hydroxyectoine and EPS. Production for the first time of both, hydroxyectoine and ectoine from CH4. Obtention of high yields of EPS using an extremophile methanotrophic consortium. Novel methanotrophic consortium able to create value out of CH4 mitigation. Abstract: This study constitutes the first-proof-of-concept of a methane biorefinery based on the multi-production of high profit margin substances (ectoine, hydroxyectoine, polyhydroxyalkanoates (PHAs) and exopolysaccharides (EPS)) using methane as the sole carbon and energy source. Two bubble column bioreactors were operated under different magnesium concentrations (0.2, 0.02 and 0.002 g L −1 ) to validate and optimize this innovative strategy for valorization of CH4 emissions. High Mg 2+ concentrations promoted the accumulation of ectoine (79.7–94.2 mg g biomass −1 ), together with high hydroxyectoine yields (up to 13 mg g biomass −1 ) and EPS concentrations (up to 2.6 g L culture broth −1 ). Unfortunately, PHA synthesis was almost negligible (14.3 mg L −1 ) and only found at the lowest Mg 2+ concentration tested. Halomonas, Marinobacter, Methylophaga and Methylomicrobium, previously described as ectoine producers, were dominant in both bioreactors, Methylomicrobium being the only described methanotroph . This study encourages further research on CH4 biorefineries capable of creating value out of GHG mitigation.