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Notes on NH4 and NO3
- To: <Aquatic-Plants at actwin_com>
- Subject: Notes on NH4 and NO3
- From: Thomas Barr <tcbiii at earthlink_net>
- Date: Sat, 08 Sep 2001 20:14:27 -0700
- In-Reply-To: <200109071948.f87Jm6203040 at actwin_com>
- User-Agent: Microsoft-Outlook-Express-Macintosh-Edition/5.02.2022
Rogers and Gallon's Book, The Biochemistry of Algae and Cyanobacteria(1988)
has a good section that seems relevant to the GW discussion. Pages 30 -39
are very interesting regarding NO3/NH4 uptakes and some CO2 issues. Also in
the Book are some indications that NO2 may inhibit NO3 uptake rates. NH4 ->
NO2 may cause this inhibition also.
"We can add that for NH4+, cells do not have an active uptake mechanism for
NO3-, this too appears when NH4+ is removed(Cresswell and Syrett 1981).
Second, that the addition of NH4 to cells assimilating NO3 rapidly inhibits
NO3 assimilation(Syrett and Morris 1963).
Algae in a NH4+ environment do NOT make nitrate reductase (for NO3 usage)
enzymes. If you remove NH4 from the water the NR will be produced(Morris and
In some cases additions of NH4 caused an efflux of NO3 from the
cells(Larsson and Larsson 1987).
Duckweed uptakes of NO3 and P where inhibited by the addition of NH4 as
well(Ullrich 1987). Some interesting stuff and some info on NO3/NH4 relating
to CO2/HCO3 levels as well.
Some algae will assimilate NH4 only at a certain concentration levels."
I would contend this is true with green water in order to get it to bloom.