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takayan
10/01/2009, 03:02 PM
I just read Japanese reef magazine called Marine Aquarist. In the magazine, the author mentioned PAO which is phosphate-accumulating organisms. PAO can accumulate Phosphate under aerobic condition. However, at the same time, K and Mg can be used by PAO for combining P. That's why those who run Bakterioplankton system like Zeovit and NeoZeo need to pay attention K and Mg.

Can anybody explain further?

luther1200
10/01/2009, 03:08 PM
I believe all living organism use some amount of PO4, but I have no idea how much or what forms.

takayan
10/02/2009, 01:11 PM
That's right. I think the population of PAO in the tank might be the point. That's why dosing carbon source to reduce P and N.

tatuvaaj
10/03/2009, 01:12 AM
takayan,

Here is a review you might find interesting... it would be interesting to test if it is possible to use the method used in wastewater treatment plants (enhanced biological phosphorus removal, EBPR) to promote Poly-P accumulating bacteria growth in aquarium conditions. You would just have to alternate anaerobic and aerobic conditions in a filter media and provide enough labile DOM (vodka etc).

I can send the PDF if you want ;)

Hupfer et al. Polyphosphate-accumulating microorganisms in aquatic sediments. Aquatic Microbial Ecology (2007)

ABSTRACT: The direct contribution of microorganisms to the mobilisation and immobilisation of phosphorus (P) in aquatic sediments has been controversially discussed for more than a decade. Some authors have speculated that the microbial P pool is highly variable in the uppermost sediment layer, especially when excessive P accumulation in the form of polyphosphate (Poly-P) occurs. Poly-P storage is a widespread ability of many different organisms in nature. The phenomenon of Poly-P storage has been technically optimised in wastewater treatment plants (WWTP) providing conditions for enhanced biological phosphorus removal. New insights into the functioning of P elimination in WWTP were strongly linked to the development of novel methods, like 31P nuclear magnetic resonance, for the detection of Poly-P and molecular biological methods for the identification of the specific microorganisms responsible for biological P elimination. Our review summarises current literature on Poly-P in aquatic systems and discusses different potential habitats and mechanisms for Poly-P storage in sediments that are more diverse than in WWTP. Poly-P in sediments may originate from benthic or pelagic hetero- and autotrophic organisms. Poly-P-accumulating organisms in sediments may be of high ecological importance, since they insert phosphorus into the benthic food chain and affect the permanent P mineral deposition in sediments by physiologically inducing rapid P release. Although several studies indicate that Poly-P substantially contributes to total P in the uppermost sediment layer (up to 10%), its origin and the microorganisms and mechanisms involved in Poly-P storage and cycling are largely unknown. Therefore, we also aim to stimulate future studies focusing on these important areas of sediment research.