Effects of Nutrient Sources and Input Mode on the Community Succession of Six Marine Microalgal Species

LIANG Ying; LIU Chunqiang; TIAN Chuanyuan; SUN Minghui

Abstract：In this paper,six marine microalgal species(Phaeodactylum tricornutum,Nitzschia closterium f.minutissima,Dunaliella salina,Platymonas helgolandica var.tsingtaoensi,Karenia mikimotoi and Amphidinium carterae)were mixed cultured under different nitrogen sources (NaNO3,NH4Cl,CO (NH2)2),different phosphorous sources (NaH2PO4,glycerophosphate,adenosine triphosphate diso-dium)and different nutrient input modes (input one time,input every 2 days,input every 5 days)in order to study the effects of nutrient sources and input modes on the community succession of six mi-croalgal species.The results showed that when NaNO3 and NH4Cl were nitrogen sources,diatoms were the dominant algae and accounted for 56.0% and 58.4% of the total cell densities,respectively, while green algae had competitive advantage when urea was nitrogen source and accounted for 56.5% of the total cell density.When NaH2PO4 and glycerophosphate were phosphorus sources,diatoms were the competitive species and accounted for 56.0% and 59.6% of the total cell densities,respectively, while green algae were dominants when adenosine triphosphate disodium was phosphorus source,ac-counting for 80.0% of the total cell density.The diatoms were all dominant in different nutrient input modes and accounted for 63.2%,85.6% and 60.4% of the total cell densities,respectively,when the nutrients were input one time,input every 2 days and input every 5 days,with the highest competitive-ness occurred in every 2 days input mode.Dinoflagellates were inhibited and only occupied small per-centages of the total cell densities in all treatments.