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Re: Aquatic Plants Digest V3 #1039

On APD #1039 Scott wrote:
"There is really no need to make such comments. Perhaps this is what the 
is known as, or wishes to be known as, It is petty to suggest that he is not
to be taken seriously because he has a nickname."

It is only common courtesy to give someone your name (at least your first 
anyway) when talking to them even if it is only in APD.

Next you said:
"Uncertain maybe, but we do know that Nitrobacter and Nitrosomonas are most 
the two genuses (hmmmm, is that the right word?)"
"It is also speculation to say that these products do not work as claimed. I
do not use them but know several people who have had success with them. I know
of no actual studies to prove that they are ineffective or effective."

I am not sure of the word you mean but I hope the following information helps 
clear up any questions.

Authors: Hovanec TA. Taylor LT. Blakis A. Delong EF . 
Source:     Applied & Environmental Microbiology. 64(1):258-264
                  1998 Jan. (Updated Jan. 1999)


           Oxidation of nitrite to nitrate in aquaria is typically attributed 
to bacteria belonging to the genus Nitrobacter which are members of the alpha 
subdivision of the class Proteobacteria. In order to identify bacteria 
responsible for nitrite oxidation in aquaria, clone libraries of rRNA genes 
were developed from biofilms of several freshwater aquaria, Analysis of the 
rDNA libraries, along with results from denaturing gradient gel 
electrophoresis (DGGE) on frequently sampled biofilms, indicated the presence 
of putative nitrite-oxidizing bacteria closely related to other members of 
the genus Nitrospira. Nucleic acid hybridization experiments with rRNA from 
biofilms of freshwater aquaria demonstrated that Nitrospira-like rRNA 
comprised nearly 5% of the rRNA extracted from the biofilms during the 
establishment of nitrification. Nitrite-oxidizing bacteria belonging to the 
alpha subdivision of the class Proteobacteria (e.g., Nitrobacter spp.) were 
not detected in these samples. Aquaria which received a commercial 
preparation containing Nitrobacter species did not show evidence of 
Nitrobacter growth and development but did develop substantial populations of 
Nitrospira-like species. Time series analysis of rDNA phylotypes on aquaria 
biofilms by DGGE, combined with nitrite and nitrate analysis, showed a 
correspondence between the appearance of Nitrospira-like bacterial ribosomal 
DNA and the initiation of nitrite oxidation. In total, the data suggest that 
Nitrobacter winogradskyi and close relatives were not the dominant 
nitrite-oxidizing bacteria in freshwater aquaria. Instead, nitrite oxidation 
in freshwater aquaria appeared to be mediated by bacteria closely related to 
Nitrospira moscoviensis and Nitrospira and marina. [References: 18] 

There are longer versions available if anyone wants a copy off-line, just 
e-mail me.

James Watford
Columbia, SC