hide
Free keywords:
-
Abstract:
The 16S rDNA genes of an apparently pure culture of a psychrophilic and
strict barophilic bacterium (WHB 46) were studied by PCR-mediated
amplification and cloning into phage M13 mp 18. Sequence analysis of
five individual clones revealed the presence of two different 16S rDNA
types. The homology value of 90% indicates that culture WHB 46 is
actually composed of two closely related species (WHB 46-1 and 46-2).
Both strains are members of the gamma-subdivision of proteobacteria.
Analysis of a sixth clone (WHB 46-1/2) leads to the conclusion that it
represents a 16S rDNA hybrid molecule assembled during the PCR reaction.
This hypothesis was confirmed by secondary structure analysis of the
chimeric rDNA. The appearance of such hybrid molecules point to a
potential risk in studies on the diversity of bacterial populations by
analysis of rDNA pattern via PCR-mediated amplification because they
suggest the existence of organisms that do not actually exist in the
sample investigated.
