Number of bacterial species

Dave Boone boone at
Wed Jan 24 11:37:48 EST 1996

There are about 4,000 currently recognized bacterial species.  Estimates
of how many undescribed species vary greatly, but estimates of the
percentage of species already known vary from a few percent to one in ten

The definition of what is a bacterial species has been widely discussed,
and there is general (though not universal) agreement that 70% DNA
interstrain hybridization is the minimum phylogenetic difference that
defines species.

dave boone
boone at

In article <4dom7g$ebc at> "Dr. David Rosen" <drosen> writes:
>Lars Andrup <ANDRUP at> wrote:
>>I have not been able to find an estimate of the number of bacterial 
>>species described so far and how many there may be "out there". I would 
>>appreciate some help very much.
>	You will need it.  The idea of species in bacteria is not 
>very well defined.  This is because their most easily recognized 
>form of reproduction is asexual, and because they have such a high 
>amount of diversity, and because morphological features are not too 
>destinctive despite the high amount of variety.  Be prepared for 
>David Rosen
>drosen at

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