Methylocystis heyeri sp. nov., a novel type II methanotrophic bacterium possessing 'signature' fatty acids of type I methanotrophs

• Published in: International journal of systematic and evolutionary microbiology Vol. 57; no. 3; pp. 472 - 479
• Main Authors: Dedysh, Svetlana N, Belova, Svetlana E, Bodelier, Paul L. E, Smirnova, Ksenia V, Khmelenina, Valentina N, Chidthaisong, Amnat, Trotsenko, Yuri A, Liesack, Werner, Dunfield, Peter F
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01-03-2007
• Subjects: DNA, Bacterial - genetics; DNA, Ribosomal - genetics; Fatty Acids - analysis; Mass Spectrometry; Methylocystaceae - chemistry; Methylocystaceae - classification; Methylocystaceae - genetics; Methylocystis parvus; Methylosinus; Molecular Sequence Data; Phylogeny; RNA, Ribosomal, 16S - genetics; Sphagnum; Wetlands
• ISSN: 1466-5026; 1466-5034
• DOI: 10.1099/ijs.0.64623-0

1 S. N. Winogradsky Institute of Microbiology, Russian Academy of Sciences, Moscow 117312, Russia
2 Netherlands Institute of Ecology, NL3631 AC Nieuwersluis, The Netherlands
3 G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region 142292, Russia
4 Joint Graduate School of Energy and Environment, King Mongkut's University of Technology, Bangkok 10140, Thailand
5 Max-Planck-Institut für terrestrische Mikrobiologie, D-35043 Marburg, Germany
6 Institute of Geological and Nuclear Sciences, Wairakei Research Centre, Taupo, New Zealand
Correspondence Svetlana N. Dedysh dedysh{at}mail.ru
A novel species is proposed for two strains of methanotrophic bacteria (H2 T and Sakb1) isolated from an acidic (pH 4.3) Sphagnum peat bog lake (Teufelssee, Germany) and an acidic (pH 4.2) tropical forest soil (Thailand), respectively. Cells of strains H2 T and Sakb1 were aerobic, Gram-negative, non-motile, straight or curved rods that were covered by large polysaccharide capsules and contained an intracytoplasmic membrane system typical of type II methanotrophs. They possessed both a particulate and a soluble methane monooxygenase and utilized the serine pathway for carbon assimilation. They were moderately acidophilic organisms capable of growth between pH 4.4 and 7.5 (optimum 5.8–6.2). The most unique characteristic of these strains was the phospholipid fatty acid profile. In addition to the signature fatty acid of type II methanotrophs (18 : 1 8 c ), the cells also contained large amounts of what was previously considered to be a signature fatty acid of type I methanotrophs, 16 : 1 8 c . The DNA G+C contents of strains H2 T and Sakb1 were 61.5 and 62.1 mol%, respectively. The 16S rRNA gene sequences possessed 96–98 % similarity to sequences of other type II methanotrophs in the genera Methylosinus and Methylocystis . 16S rRNA gene sequence and pmoA phylogeny demonstrated that the strains form a novel lineage within the genus Methylocystis . DNA–DNA hybridization values of strain H2 T with Methylocystis parvus OBBP T and Methylocystis echinoides IMET 10491 T were 18 and 25 %, respectively. Thus, it is proposed that these two strains represent a novel species, Methylocystis heyeri sp. nov. Strain H2 T (=DSM 16984 T =VKM B-2426 T ) is the type strain.
Abbreviations: DMDS, dimethyldisulfide; FAME, fatty acid methyl ester; ICM, intracytoplasmic membrane; MDH, methanol dehydrogenase; PLFA, phospholipid fatty acid; pMMO, particulate methane monooxygenase; sMMO, soluble methane monooxygenase
The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequence and partial sequences of the mxaF , mmoX and pmoA genes of Methylocystis heyeri strain H2 T are AM283543 –AM283546, respectively.
A supplementary figure showing mass spectra of DMDS adducts of 16 : 1 PLFA of strain H2 T is available in IJSEM Online.