title: Valorization of CH4 emissions into high-added-value products: Assessing the production of ectoine coupled with CH4 abatement.
abstract: This study assessed an innovative strategy for the valorization of dilute methane emissions based on the bio-conversion of CH4 (the second most important greenhouse gas (GHG)) into ectoine by the methanotrophic ectoine-producing strain Methylomicrobium alcaliphilum 20 Z. The influence of CH4 (2-20%), Cu(2+) (0.05-50 μM) and NaCl (0-9%) concentration as well as temperature (25-35 °C) on ectoine synthesis and specific CH4 biodegradation rate was evaluated for the first time. Concentrations of 20% CH4 (at 3% NaCl, 0.05 μM Cu(2+), 25 °C) and 6% NaCl (at 4% CH4, 0.05 μM Cu(2+), 25 °C) supported the maximum intra-cellular ectoine production yield (31.0 ±1.7 and 66.9 ±4.2 mg g biomass(-1), respectively). On the other hand, extra-cellular ectoine concentrations of up to 4.7 ± 0.1 mg L(-1) were detected at high Cu(2+)concentrations (50 μM), despite this methanotroph has not been previously classified as an ectoine-excreting strain. This research demonstrated the feasibility of the bio-conversion of dilute emissions of methane into high-added value products in an attempt to develop a sustainable GHG bioeconomy.
authors.affiliation: Department of Chemical Engineering and Environmental Technology, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Cantera
authors.affiliation: Department of Chemical Engineering and Environmental Technology, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Lebrero
authors.affiliation: Department of Chemical Engineering and Environmental Technology, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain.
authors.forename: Lidia
authors.initials: L
authors.lastname: Sadornil
authors.affiliation: Department of Chemical Engineering and Environmental Technology, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: García-Encina
authors.affiliation: Department of Chemical Engineering and Environmental Technology, Valladolid University, Dr. Mergelina, s/n, Valladolid, Spain. Electronic address: mutora@iq.uva.es.
authors.forename: Raúl
authors.initials: R
authors.lastname: Muñoz
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D000599:Amino Acids, Diamino / Q000737:chemistry*; D001673:Biodegradation, Environmental; D019149:Bioreactors; D006801:Humans; D008697:Methane / Q000737:chemistry*; D013696:Temperature
chemical_list: D000393:Air Pollutants; D000599:Amino Acids, Diamino; C045628:ectoine; D008697:Methane
keywords: Ectoine; Greenhouse gas; Methane biorefinery; Methane treatment