The objective of this project was to use ribosomal RNA genes, cloned
from natural populations of Sargasso Sea bacterioplankton, as markers for
picoplankton diversity. It is widely recognised that a majority of
microorganisms have yet to be cultivated, and therefore much of extant
microbial diversity remains unknown (50). The method described here for
analyzing natural bacterial communities circumvents this problem by
utilizing ribosomal RNA, found in all life forms, for defining and
enumerating the components of natural populations. Two different clone
libraries of eubacterial 16S rRNA genes amplified from a natural population
of Sargasso Sea picoplankton by the polymerase chain reaction (11) have
been phylogenetically analysed. The analyses indicate the presence of a wide
variety of novel microorganisms, representing members of the α and γ
proteobacteria and the oxyphototroph (13, 47) eubacterial phyla. One group
of novel clones, represented by SAR 83, were found to be most closely related
to Erythrobacter, a genus of aerobic bacteriochlorophyll~ containing
organisms. The results imply that many closely related 16S rRNA lineages,
or clusters of lineages, coexist within bacterioplankton communities. The
significance of these clusters is uncertain. One interpretation, that they
represent clonal structure within bacterial species, suggests that populations
of marine bacteria are very ancient. / Graduation date: 1991
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/38140 |
| Date | 28 June 1990 |
| Creators | Britschgi, Theresa Baden |
| Contributors | Giovannoni, Stephen J. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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