Growth and nitrogen uptake kinetics in cultured Prorocentrum donghaiense.
We compared growth kinetics of Prorocentrum donghaiense cultures on different nitrogen (N) compounds including nitrate (NO3-), ammonium (NH4+), urea, glutamic acid (glu), dialanine (diala) and cyanate. P. donghaiense exhibited standard Monod-type growth kinetics over a range of N concentraions (0.5-500 μmol N L-1 for NO3- and NH4+, 0.5-50 μmol N L-1 for urea, 0.5-100 μmol N L-1 for glu and cyanate, and 0.5-200 μmol N L-1 for diala) for all of the N compounds tested. Cultures grown on glu and urea had the highest maximum growth rates (μm, 1.51±0.06 d-1 and 1.50±0.05 d-1, respectively). However, cultures grown on cyanate, NO3-, and NH4+ had lower half saturation constants (Kμ, 0.28-0.51 μmol N L-1). N uptake kinetics were measured in NO3--deplete and -replete batch cultures of P. donghaiense. In NO3--deplete batch cultures, P. donghaiense exhibited Michaelis-Menten type uptake kinetics for NO3-, NH4+, urea and algal amino acids; uptake was saturated at or below 50 μmol N L-1. In NO3--replete batch cultures, NH4+, urea, and algal amino acid uptake kinetics were similar to those measured in NO3--deplete batch cultures. Together, our results demonstrate that P. donghaiense can grow well on a variety of N sources, and exhibits similar uptake kinetics under both nutrient replete and deplete conditions. This may be an important factor facilitating their growth during bloom initiation and development in N-enriched estuaries where many algae compete for bioavailable N and the nutrient environment changes as a result of algal growth.
Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Research Center of Hydrobiology, Jinan University, Guangzhou, Guangdong, China.
Zhangxi
Z
Hu
Research Center of Hydrobiology, Jinan University, Guangzhou, Guangdong, China.
Shunshan
S
Duan
Research Center of Hydrobiology, Jinan University, Guangzhou, Guangdong, China.
Ning
N
Xu
Department of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, Virginia, United States of America.
Margaret R
MR
Mulholland
D056893:Alveolata / Q000254:growth & development* / Q000378:metabolism; D057097:Harmful Algal Bloom / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism*
D009584:Nitrogen