Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543.
Appl Environ Microbiol. 1986 Dec;52(6):1340-7. doi: 10.1128/aem.52.6.1340-1347.1986.
The effect of temperature on the rates and extent of carbon and nitrogen cycling by the heterotrophic microflagellate Paraphysomonas imperforata (diameter, 7 to 12 mum) fed with the diatom Phaeodactylum tricornutum was investigated over an ecologically pertinent temperature range (14 to 26 degrees C). All physiological rates investigated increased with increasing temperature. Q(10) values were similar for all rate changes and were comparable to those which have been reported for other protozoa. In contrast to all rates, microflagellate gross growth efficiency and cell volume were unaffected by temperature. Decreases in the concentrations of particulate carbon and particulate nitrogen from grazed diatom cultures also were similar when summed over the entire growth phase of the microflagellate population. Therefore, the proportions of ingested carbon and nitrogen which were incorporated or remineralized by the microflagellate were independent of temperature between 14 and 26 degrees C. At temperatures above 18 degrees C, growth rates of P. imperforata were greater than the maximum growth rates reported for most phytoplankton. We conclude that the impact of P. imperforata on natural phytoplankton communities is not controlled by temperature above 18 degrees C but may be affected by the rate at which zooplankton or microzooplankton prey on the microflagellate, as well as the inability of the microflagellate to graze efficiently when phytoplankton are present at low cell densities.
温度对异养微型鞭毛藻 Paraphysomonas imperforata（直径 7 至 12 微米）在以硅藻 Phaeodactylum tricornutum 为食时的碳氮循环速率和程度的影响，在一个具有生态相关性的温度范围内（14 至 26°C）进行了研究。所有研究的生理速率都随温度升高而增加。所有速率变化的 Q10 值相似，与其他原生动物报道的 Q10 值相当。与所有速率相反，微型鞭毛藻的总生长效率和细胞体积不受温度影响。从被吞噬的硅藻培养物中，颗粒态碳和颗粒态氮的浓度下降在整个微型鞭毛藻种群的生长阶段加起来也是相似的。因此，在 14 至 26°C 之间，被微型鞭毛藻吸收或再矿化的碳和氮的比例与温度无关。在 18°C 以上的温度下，P. imperforata 的生长速率大于大多数浮游植物的最大生长速率。我们的结论是，在 18°C 以上的温度下，P. imperforata 对自然浮游植物群落的影响不受温度控制，但可能受到浮游动物或微型浮游动物捕食微型鞭毛藻的速度以及微型鞭毛藻在浮游植物细胞密度低时无法有效捕食的影响。
