Effect of nutrient availability on nitrogen and phosphorus uptake rate,growth rate and the content of phycoerythrin in Porphyra haitanensis

The effect of nutrient availability on the uptake rates of nitrogen(N) and phosphorus(P),and the effect of P concentration on the growth rate and phycoerythrin content in Porphyra haitanensis were studied under laboratory conditions.The uptake rates of N and P increased with their concentrations in the media,and approached the highest at DIN more than 100 μmol/L;the combination of NO3——N and NH4+-N also affected the uptake of N by P.haitanensis,and the best combination of NO3——N and NH4+-N is NO3——N∶NH4+-N=1∶5;the N uptake rate increased while the P uptake rate decreased with N∶P increase;the growth rate and PE content in P.haitanensis increased with the increase of P when the concentration of P was below 12 μmol/L.