Nitrogen, Total Kjedahl
This total nitrogen test reveals the quantity of the macro-nutrient available. Nitrogen is the building block for peptides and amino acids. Combined with the total carbon analysis, this test can give a picture of the carbon to nitrogen ratio. If this ratio is too low in carbon, nitrogen in the form of ammonia can rise to toxic levels. If the carbon is too high, the lack of nitrogen may be limiting the growth rate and require additional nitrogen supplements or co-substrates rich in N.