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U.S. Department of Energy
Office of Scientific and Technical Information

Identification of subsurface microorganisms at Yucca Mountain; Second quarterly report, October 1, 1993--December 31, 1993

Technical Report ·
DOI:https://doi.org/10.2172/144913· OSTI ID:144913
The primary effort of this past quarter was to develop a procedure where accumulated data files could be evaluated to determine the naming consistency and inter-relationships of the various species which have been identified by the Microbial Identification System (MIDI) system. This involved a series of steps, including the clustering of similarly named organisms in a dendrogram format to determine how closely similarly named isolates are related. The experience of other researchers using the MIDI system has shown that clusters which are joined at a Euclidian distance of 10 or less belong to the same species. Strains which are very similar cluster at less than 6 Euclidian units and clusters below two units have nearly identical fatty acid patterns. When the dendrograms derived from the springs were scrutinized, some organisms were found which did not match the pattern of their named group. Then a decision was made whether to rename the isolates and exclude them from the group or redefine the group. This decision was assisted by plotting the principal components derived from an analysis of the fatty acid composition of members of the genus. Each species can be examined by the same procedure to determine group homogeneity. In these 2-dimensional plots members of the same species are roughly bounded by a box of 100 squared units while closely related strains are grouped more tightly together. The 2-dimensional plot of isolates of Micrococcus luteus demonstrates the presence of three identifiable sub-species.
Research Organization:
Nevada Univ., Las Vegas, NV (United States). Harry Reid Center for Environmental Studies
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FC08-90NV10872
OSTI ID:
144913
Report Number(s):
DOE/NV/10872--T94; ON: DE94007780
Country of Publication:
United States
Language:
English