Methylosarcina fibrata gen. nov., sp. nov. and Methylosarcina quisquiliarum sp. nov., novel type I methanotrophs
MG Wise, JV McArthur and LJ Shimkets Department of Microbiology, University of Georgia, Athens, GA 30602-2605, USA Two novel species of obligate methane-oxidizing bacteria, isolated from landfill soil, were characterized. Both strains were unusual in that some members of the population grew in irreg...
Saved in:
Published in | International journal of systematic and evolutionary microbiology Vol. 51; no. 2; pp. 611 - 621 |
---|---|
Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Reading
Soc General Microbiol
01.03.2001
Society for General Microbiology |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | MG Wise, JV McArthur and LJ Shimkets
Department of Microbiology, University of Georgia, Athens, GA 30602-2605, USA
Two novel species of obligate methane-oxidizing bacteria, isolated from
landfill soil, were characterized. Both strains were unusual in that some
members of the population grew in irregularly shaped, refractile cell
packets that resembled sarcina-like clusters. Electron microscopy revealed
that the cell packets were covered with a slime layer and the cells
contained many large granular inclusion bodies. The individual cells of
each strain were sometimes motile and had differing morphologies. Isolate
AML-C10(T) was always coccoidal in shape, and the cells were covered with
extracellular fibrils. Isolate AML-D4(T) was pleomorphic, changing from rod
to coccal form, sometimes exhibiting an unusual fusiform morphology.
AML-D4(T) lacked the extensive fibrillar matrix observed with AML-C10(T).
Both strains utilized only methane and methanol as carbon sources. In
stationary phase, the cells of each strain swelled in size and formed
cysts. Aside from morphological differences, strains could also be
distinguished from each other by cellular protein patterns, as well as by
temperature and pH tolerances. 16S rDNA phylogenetic analysis showed that
these are type I methanotrophs (family: Methylococcaceae) most closely
related to the Methylobacter/Methylomicrobium clade, although they form a
monophyletic grouping supported by moderately high bootstrap values. By 16S
rDNA database searches, the most similar species to both isolates were
Methylobacter spp. However, partial particulate methane monooxygenase
sequence analysis suggested that these bacteria might be more closely
related to Methylomicrobium than Methylobacter. Furthermore, cellular fatty
acid profiles of the strains more closely resemble those of
Methylomicrobium, although the absence of significant levels of 16:1omega5c
argues for the uniqueness of these two strains. On the basis of the results
described here, it is proposed that a new genus should be created,
Methylosarcina gen. nov., harbouring two species, Methylosarcina fibrata
sp. nov. (type species) and Methylosarcina quisquiliarum sp. nov. The type
strains are AML-C10(T) (=ATCC 700909(T)=DSM 13736(T)) and AML-D4(T) (=ATCC
700908(T)=DSM 13737(T)), respectively. |
---|---|
Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 1466-5026 1466-5034 |
DOI: | 10.1099/00207713-51-2-611 |