Peter Herman herman at
Fri Aug 18 02:59:11 EST 1995

: Does anyone know of published or reference methods for quantifying 
: nitrate and/or nitrite oxidising and/or reducing bacteria in water?
: I'ld be grateful for any leads!
: Please reply to this newsgroup, or E-mail me on Beccas at
: Thanks in advance!
: -- 

There is a good reference for NH4 and NO2 oxidizers in low N soil
environments which could be easily modified for water.  It relies on MPNs
with a pH change as an indicator of activity (growth is so blasted slow 
that turbidity is useless):  The reference is:

Donaldson JM, and GS Henderson. 1989. A dilute medium to determine
population size of ammonia oxidizers in forest soils. Soil Soc. Am. J.

We use it in desert soils where NH4 is low and have very good luck.  Much 
better than with "normal" strength media.

For NO3 reducers, if you have a way to keep them anaerobic, plates will 
work.  We have very limited anaerobic facilities so use an MPN approach.  
We use a dilute (20-50% strength) TSB tube with 5mN NO3 and a Durham tube 
for gas collection (N2).  The tubes are Hungate Tubes  (screw tops/black 
butyl septa) and are sparged with N in the normal way.  A positive is 
turbidity plus gas

Be patient, both types of tubes can take a month to turn.  Be sure to 
keep the NH4 oxidizers in the dark or you will have boatloads of algae!

Good luck

R. Peter Herman				email	Peter.Herman at
Sveriges Lantbruksuniversitet		Phone:	+46 18 67 12 20
Inst. f. Markvetenskap			Fax:	+46 18 67 27 95
S750 07 Uppsala, Sweden		

More information about the Microbio mailing list