STUDIES OF CARBON AND NITROGEN METABOLISM BY THREE MARINE PHYTOPLANKTON SPECIES IN NITRATE‐LIMITED CONTINUOUS CULTURE1,2

作者：Edward Allen Laws, Diana C. L. Wong · 发表于：Journal of Phycology · 年份：1978 · DOI：10.1111/j.1529-8817.1978.tb02460.x · 被引用次数：102 · 研究领域：Marine and coastal ecosystems、Marine Bivalve and Aquaculture Studies、Aquatic Ecosystems and Phytoplankton Dynamics

ABSTRACT Characteristics of carbon production, excretion and dark respiration, and nitrate uptake kinetics were studied using continuous culture techniques forThalassiosira alleniiTakano, Monorhrysis lutheri Droop and Dunaliella tertiolcctaButcher. FurT. allenii.the ratio of dark C loss to daytime net C production varied between 0.1 and 0.2 over a growth rate range from ca. 0.005 to 0.06 h‐1. ForM. lutheriandD. tertiolecta.this same ratio varied belween 0.2 and 0.3 between growth rates of ca. 0.005 and 0.025 h‐1, but declined at higher growth rates when the dark nitrate uptake capacity of the cells was exceeded by the pumping rate. Carbon excretion rates averaged less than 1.5% of daytime net C production rates. Productivity indices showed little correlation with growth rate, due to the significant poisitive correlation between chla:C ratios and growth rate. Chlorophylla:C ratios forT. alleniiwere less than 0.01 al growth rates less than 0.03 h‐1, and appoached zero at zero growth rate. Dark nitrate maximum uptake rates forM. lutheri, D. tertiolectaandT. alleniiaveraged 23, 64 and 120%, respectively, of light nitrate maximum uptake rates. Excretion of nitrite was observed during most nitrate uptake experiments. This excretion reduced net uptake of nitrate spikes in the dark forM. lutheriandD. tertiolectaby 79 and 23%, respectively.