NO3/NO2 OXIDISING/REDUCING BACTERIA

Peter Herman herman at populus.slu.se
Fri Aug 18 02:59:11 EST 1995


REBECCA MILLS (REBECCA at beccas.demon.co.uk) wrote:
: 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 demon.co.uk
: Thanks in advance!
: -- 
: REBECCA MILLS

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.
53:11608-1611. 

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

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