Valorization of CH^sub 4^ emissions into high-added-value products: Assessing the production of ectoine coupled with CH^sub 4^ abatement

• Published in: Journal of environmental management 2016-11, Vol.182, p.160
• Main Authors: Cantera, Sara, Lebrero, Raquel, Sadornil, Lidia, García-Encina, Pedro A, Muñoz, Raúl
• Format: Article
• Language: English
• Subjects: Biodegradation; Biomass; Emissions; Methane; Temperature
• ISSN: 0301-4797; 1095-8630

This study assessed an innovative strategy for the valorization of dilute methane emissions based on the bio-conversion of CH^sub 4^ (the second most important greenhouse gas (GHG)) into ectoine by the methanotrophic ectoine-producing strain Methylomicrobium alcaliphilum 20 Z. The influence of CH^sub 4^ (2-20%), Cu^sup 2+^ (0.05-50 ...M) and NaCl (0-9%) concentration as well as temperature (25-35 ...C) on ectoine synthesis and specific CH^sub 4^ biodegradation rate was evaluated for the first time. Concentrations of 20% CH^sub 4^ (at 3% NaCl, 0.05 ...M Cu^sup 2+^, 25 ...C) and 6% NaCl (at 4% CH^sub 4^, 0.05 ...M Cu^sup 2+^, 25 ...C) supported the maximum intra-cellular ectoine production yield (31.0 ±1.7 and 66.9 ±4.2 mg g biomass^sup -1^, respectively). On the other hand, extra-cellular ectoine concentrations of up to 4.7 ± 0.1 mg L^sup -1^ were detected at high Cu^sup 2+^concentrations (50 ...M), 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. (ProQuest: ... denotes formulae/symbols omitted.) [web URL: http://www.sciencedirect.com/science/article/pii/S0301479716305011]