title: Bacterial metabolism of methylated amines and identification of novel methylotrophs in Movile Cave.
abstract: Movile Cave, Romania, is an unusual underground ecosystem that has been sealed off from the outside world for several million years and is sustained by non-phototrophic carbon fixation. Methane and sulfur-oxidising bacteria are the main primary producers, supporting a complex food web that includes bacteria, fungi and cave-adapted invertebrates. A range of methylotrophic bacteria in Movile Cave grow on one-carbon compounds including methylated amines, which are produced via decomposition of organic-rich microbial mats. The role of methylated amines as a carbon and nitrogen source for bacteria in Movile Cave was investigated using a combination of cultivation studies and DNA stable isotope probing (DNA-SIP) using (13)C-monomethylamine (MMA). Two newly developed primer sets targeting the gene for gamma-glutamylmethylamide synthetase (gmaS), the first enzyme of the recently-discovered indirect MMA-oxidation pathway, were applied in functional gene probing. SIP experiments revealed that the obligate methylotroph Methylotenera mobilis is one of the dominant MMA utilisers in the cave. DNA-SIP experiments also showed that a new facultative methylotroph isolated in this study, Catellibacterium sp. LW-1 is probably one of the most active MMA utilisers in Movile Cave. Methylated amines were also used as a nitrogen source by a wide range of non-methylotrophic bacteria in Movile Cave. PCR-based screening of bacterial isolates suggested that the indirect MMA-oxidation pathway involving GMA and N-methylglutamate is widespread among both methylotrophic and non-methylotrophic MMA utilisers from the cave.
authors: School of Environmental Sciences, University of East Anglia, Norwich, UK.
authors: Daniela
authors: D
authors: Wischer
authors: School of Environmental Sciences, University of East Anglia, Norwich, UK.
authors: Deepak
authors: D
authors: Kumaresan
authors: School of Environmental Sciences, University of East Anglia, Norwich, UK.
authors: Antonia
authors: A
authors: Johnston
authors: School of Environmental Sciences, University of East Anglia, Norwich, UK.
authors: Myriam
authors: M
authors: El Khawand
authors: School of Life Sciences, University of Warwick, Coventry, UK.
authors: Jason
authors: J
authors: Stephenson
authors: Department of Biospeleology and Karst Edaphobiology, Emil Racoviţă Institute of Speleology, Bucharest, Romania.
authors: Alexandra M
authors: AM
authors: Hillebrand-Voiculescu
authors: School of Life Sciences, University of Warwick, Coventry, UK.
authors: Yin
authors: Y
authors: Chen
authors: School of Environmental Sciences, University of East Anglia, Norwich, UK.
authors: J
authors: J
authors: Colin Murrell
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism; D019731:Carbon-Nitrogen Ligases / Q000235:genetics / Q000378:metabolism*; D059552:Caves; D017753:Ecosystem; D005971:Glutamates / Q000235:genetics / Q000378:metabolism*; D008744:Methylamines / Q000378:metabolism*; D042762:Methylophilaceae / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000032:analysis / Q000235:genetics; D012383:Romania
chemical_list: D005971:Glutamates; D008744:Methylamines; C476559:N-methylglutamate; D012336:RNA, Ribosomal, 16S; C027451:methylamine; D019731:Carbon-Nitrogen Ligases; C020661:gamma-glutamylmethylamide synthetase