No, because other environmental factors, most notably light, will also affect the growth and uptake of nutrients. So you need more parameters for you model to work.

I know, but the effects of other parameters aside, you see that different studies deal with determining KN or KP and you can easily calculate them from one set of experiment. But my problem is that for different initial N or P concentrations, if you plot the diagrams, then you will obtain different Ks. Do you know how to analyze all those data altogether to get only one K value for either N or P?

There is a nice paper reviewing all kinetcs models available to describe the influence of light and temperature on microalgae growht

Modeling the effects of light and temperature on algae growth: State of the art and critical assessment for productivity prediction during outdoor cultivationReview Article

Biotechnology Advances, Volume 31, Issue 8, December 2013, Pages 1648-1663

Quentin Béchet, Andy Shilton, Benoit Guieysse

I hope this will help

Thank you Raul

yes i have read this article before, but it doesn't explain how to calculate different parameters in a specific growth model.

This model applies to bacteria (studied by J. Monod) and perhaps very small algae such as picocyanobacteria that do not change their N or P content much. For larger algae, the model is generally considered invalid because growth depends on internal nutrient (N or P) and not external pools. For example, the dinoflagellate Alexandrium catenella can change its N content by a factor of five, so that it can keep growing after N is exhausted from the medium. The Droop model is then more appropriate for those organisms.

Yves:

As far as I see, this is a more complicated model since it deals with intracellular compositions. Do you think that for engineering projects, I have to go deep into this much accuracy ? then how other people's work are valid according to this model? I mean you think Monod model is far from what is in reality for micoralgae?

Well I meant total cell N or total cell P that are relatively easy to measure. There are many references linking such variables to algal growth rates. The only constraint of the Droop model is that it is applicable to cultures only, not to the field situations.

Dear Hossein Amini   

Please see chapters 3, 5 and 6 of Professor Najfpour’s newly published book "Biochemical Engineering & Biotechnology" 2nd Edition Elsevier 2015 (ISBN: 9780444633576).

You can find the contents of "Biochemical Engineering & Biotechnology" from added file here.

Book Biochemical Engineering & Biotechnolgy

The value you calculate is Mu is not Mumax , You can not calculate mu max for one concentration , so you should the set of experiments you have done to plot U against different initial concentrations of nutrient , then you can calculate Umax and K .