Metabolic inhibition of size-fractionated marine plankton radiolabeled with amino acids, glucose, bicarbonate, and phosphate in the light and dark
Metabolic inhibition of size-fractionated marine plankton radiolabeled with amino acids, glucose, bicarbonate, and phosphate in the light and dark
复制标题
在光照和黑暗条件下用氨基酸、葡萄糖、碳酸氢盐和磷酸盐放射性标记的大小分级海洋浮游生物的代谢抑制
作者：
William K. W. Li;P. Dickie
在暴露于或屏蔽环境太阳辐射的实验孵育过程中，研究了各种代谢抑制剂（二氯苯基二甲脲、氯霉素、环己亚胺、羰基氰化物间氯苯基腙）对马尾藻海和加拿大东部北极地区大小分级海洋微生物浮游生物放射性标记底物（氨基酸、葡萄糖、碳酸氢盐、磷酸盐）积累的影响。浮游生物占组合积累的有机底物和磷酸盐的65%以上。太阳辐射在某些情况下刺激了有机底物的积累速率，但在其他情况下则受到抑制。据推测，刺激和抑制同时发生，测量的反应是这些抵消趋势产生的净结果。马尾藻海中约40%的H14 CO3−积累与浮游生物有关。皮浮游生物14c标记对环己亚胺的不敏感表明活性的原核光合作用而不是14c标记的藻类光合作用的异养同化作为标记途径。一些抑制剂的有用性在本研究中受到限制，因为在实验期间，预期的初级代谢效应与测量的生态反应之间的相关性不一致。
The effects of various metabolic inhibitors (dichlorophenyl dimethylurea, chloramphenicol, cycloheximide, carbonyl cyanide m-chlorophenyl hydrazone) on the accumulation of radiolabeled substrates (amino acids, glucose, bicarbonate, phosphate) by size-fractionated marine microbial plankton from the Sargasso Sea and the eastern Canadian arctic were studied in time-course fashion during experimental incubations either exposed to or shielded from ambient solar radiation. Picoplankton accounted for ≥65% of the organic substrates and phosphate accumulated by the assemblages. The rate of organic substrate accumulation was stimulated by solar radiation in some cases but inhibited in other cases. Presumably, stimulation and inhibition co-occur and the measured response is the net result arising from these counteracting tendencies. Approximately 40% of H14 CO3− accumulation in the Sargasso Sea was associated with the picoplankton. The insensitivity of picoplankton14C-labeling to cycloheximide suggested active prokaryotic photosynthesis rather than heterotrophic assimilation of14C-labeled algal photosynthates as the route of labeling. The usefulness of some inhibitors was restricted in this study because of inconsistent correlations between the intended primary metabolic effect and the measured ecological response within the duration of the experiment.