Comparative phosphorus nutrition of the marine cyanobacterium Synechococcus WH7803 and the marine diatom Thalassiosira weissflogii
Comparative phosphorus nutrition of the marine cyanobacterium Synechococcus WH7803 and the marine diatom Thalassiosira weissflogii
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DOI：
10.1093/plankt/19.12.1793
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发表时间：
1997-12-01
影响因子：
2.1
通讯作者：
Joint, I
中科院分区：
文献类型：
--
作者：
Donald, KM;Scanlan, DJ;Joint, I
在无菌分批培养条件下研究了聚球藻WH 7803和威氏海链藻对磷的吸收动力学。磷酸盐充足的聚球藻WH 7803细胞对无机磷酸盐（Pi）的亲和力（K-s = 67 μ mol l（-1））低于Pi饥饿的细胞（K-s = 3.1 μ mol l（-1））。在黑暗中孵育或加入解偶联剂羰基氰化物对三氟甲氧基苯腙（FCCP）后，Pi饥饿细胞的Ki增加了约5倍（K-s = 14-20 μ mol l（-1））。富含Pi和缺乏Pi的T. Weissfloclavin对磷酸盐显示相似的亲和力（K-s分别为6.6和8.9 μ mol·l（-1））。在这两种情况下，在黑暗中孵育都会增加Ki值。当生物体相互竞争培养时，Pi吸收速率取决于细胞的Pi状态：Pi-充足的魏氏梭菌显示出比Pi-充足的聚球藻WH 7803更快的Pi吸收，而Pi-饥饿的魏氏梭菌显示出比聚球藻WH 7803更慢的吸收速率。当以一系列有机磷酸盐化合物的形式提供磷（P）时，T. weissflococcus和Synechococcus sp.WH7803都可以吸收磷（P），磷酸盐基团从有机磷酸盐分子上裂解并掺入。这两种微生物都能从dCTP、磷酸对硝基苯酯、葡萄糖-6-磷酸和甘油磷酸中裂解并掺入磷; weissflorescens生长与环AMP作为唯一的P源。测定了从核苷酸dCTP中摄取P的动力学;磷酸盐充足的聚球藻WH 7803细胞对来自dCTP的P的亲和力（K-s = 60 μ mol l（-1））低于Pi饥饿的细胞（K-s = 8 μ mol l（-1））。富含Pi和缺乏Pi的T. weissfloprotein对来自dCTP的P表现出相似的亲和力（K-s值分别为43和48 μ mol/l）。
Phosphate uptake kinetics of Synechococcus sp. WH7803 and Thalassiosira weissflogii were studied in axenic batch culture. Phosphate-replete Synechococcus sp. WH7803 cells have a lower affinity for inorganic phosphate (Pi) (K-s = 67 mu mol l(-1)) than Pi-starved cells (K-s = 3.1 mu mol l(-1)). The K, of Pi-starved cells increased similar to 5-fold (K-s = 14-20 mu mol l(-1)) following incubation in the dark or upon addition of the uncoupler carbonyl cyanide p-trifluoromethoxy phenylhydrazone (FCCP). Pi-replete and Pi-starved T. weissflogii exhibit similar affinities for phosphate (K-s of 6.6 and 8.9 mu mol l(-1), respectively). In both cases, K, values are increased by incubation in the dark. The rate of Pi uptake, when the organisms were cultured in competition with each other, was dependent on the Pi state of the cells: Pi-replete T.weissflogii displayed faster Pi uptake than Pi-replete Synechococcus sp. WH7803, whereas Pi-starved T.weissflogii displayed a slower rate of uptake than Synechococcus sp. WH7803. Both T.weissflogii and Synechococcus sp. WH7803 could take up phosphorus (P) when it was supplied as a range of organic phosphate compounds, the phosphate groups being cleaved from the organic phosphate molecule and incorporated. Both organisms could cleave and incorporate phosphorus from dCTP, p-nitrophenyl phosphate, glucose-6-phosphate and glycerol phosphate; however, only T. weissflogii grew with cyclic AMP as the sole P source. Uptake kinetics of P from the nucleotide dCTP were determined; phosphate-replete Synechococcus sp. WH7803 cells have a lower affinity for P from dCTP (K-s = 60 mu mol l(-1)) than Pi-starved cells (K-s = 8 mu mol l(-1)). Pi-replete and Pi-starved T. weissflogii exhibit similar affinities for P from dCTP (K-s values are 43 and 48 mu mol l(-1), respectively).