Open AccessEnrichment of ANME‐2 dominated anaerobic methanotrophy from cold seep sediment in an external ultrafiltration membrane bioreactor
Author(s) -
Bhattarai Susma,
Cassarini Chiara,
Rene Eldon R.,
Kümmel Steffen,
Esposito Giovanni,
Lens Piet N. L.
Publication year - 2018
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.201700148
Subject(s) - ultrafiltration (renal) , sulfate reducing bacteria , bioreactor , anaerobic oxidation of methane , sulfate , environmental chemistry , archaea , biomass (ecology) , chemistry , methane , seawater , bacteria , biology , chromatography , ecology , organic chemistry , genetics
Anaerobic oxidation of methane (AOM) coupled to sulfate reduction is a microbially mediated unique natural phenomenon with an ecological relevance in the global carbon balance and potential application in biotechnology. This study aimed to enrich an AOM performing microbial community with the main focus on anaerobic methanotrophic archaea (ANME) present in sediments from the Ginsburg mud volcano (Gulf of Cadiz), a known site for AOM, in a membrane bioreactor (MBR) for 726 days at 22 (± 3)°C and at ambient pressure. The MBR was equipped with a cylindrical external ultrafiltration membrane, fed a defined medium containing artificial seawater and operated at a cross flow velocity of 0.02 m/min. Sulfide production with simultaneous sulfate reduction was in equimolar ratio between days 480 and 585 of MBR operation, whereas methane consumption was in oscillating trend. At the end of the MBR operation (day 726), the enriched biomass was incubated with 13 C labeled methane, 13 C labeled inorganic carbon was produced and the AOM rate based on 13 C‐inorganic carbon was 1.2 μmol/(g dw d). Microbial analysis of the enriched biomass at 400 and 726 days of MBR operation showed that ANME‐2 and Desulfosarcina type sulfate reducing bacteria were enriched in the MBR, which formed closely associated aggregates. The major relevance of this study is the enrichment of an AOM consortium in a MBR system which can assist to explore the ecophysiology of ANME and provides an opportunity to explore the potential application of AOM.