Production of glycine betaine and dimethylsulfoniopropionate in marine phytoplankton. I. Batch cultures
Production of glycine betaine and dimethylsulfoniopropionate in marine phytoplankton. I. Batch cultures
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DOI：
10.1007/s002270050621
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发表时间：
1999-11-01
期刊：
影响因子：
2.4
通讯作者：
Bellows, WK
中科院分区：
文献类型：
--
作者：
Keller, MD;Kiene, RP;Bellows, WK
含氮化合物甘氨酸甜菜碱(GBT)及其硫磺类似物二甲基磺酸丙酸酯(DMSP)对海洋浮游植物细胞内库的定量意义尚不清楚。在1993年8月进行的一系列实验中，我们测量了6个海洋浮游植物的生长周期中这些化合物以及总有机硫、碳和氮的含量。Lackey、Emily huxleyi Hay et Mohler、微小原甲藻(Paviillard)Schiller、中肋骨条藻Sketonema costatum(Greville)Cleve和四棱藻Tetraselmis sp.同时，我们测量了细胞内蛋白质、氨基酸、叶绿素和无机营养素的浓度。所有六个物种都产生了DMSP，而三个产生的物种的水平较低。在金色假单胞菌中，金色假单胞菌在对数生长期，GET水平高于DMSP，但随着培养接近稳定期，GET水平急剧下降。这一变化似乎与氮素限制的开始相一致。六种植物中有五种产生了其他含氮渗透分子，但数量要少得多。DMSP在整个生长周期中对细胞硫的贡献很大，尽管在一些藻类中，在静止生长期间溶解的DMSP的比例大幅增加。当存在时，只在指数生长过程中形成相当大一部分细胞氮。即使当蛋白质、氨基酸、无机氮和含氮渗透分子的细胞池结合在一起时，也无法解释相当大的比例(约50%)的有机氮。根据这些实验，DMSP和GET产量之间似乎没有相互作用的关系，尽管GET产量似乎确实与氮素有效性相关。
The quantitative significance of the nitrogenous compound glycine betaine (GBT) and its sulfur analog dimelhylsulfoniopropionate (DMSP) to intracellular pools in marine phytoplankton is not well known. In a series of experiments conducted in August 1993, we measured these compounds, as well as total organic sulfur, carbon, and nitrogen, over the growth cycle in six isolates of marine phytoplankton, Amphidinium car ferae Hulburt, Chrysocromulina sp. Lackey, Emiliania huxleyi Hay et Mohler, Prorocentrum minimum (Pavillard) Schiller, Skeletonema costatum (Greville) Cleve, and Tetraselmis sp. At the same time, we measured cellular concentrations of protein, amino acids, chlorophyll, and inorganic nutrients. All six species produced DMSP, while three produced GET at lesser levels. In the Chrysochromulina sp. isolate, levels of GET were greater than DMSP during the exponential phase of growth, but declined sharply as the culture approached stationary phase. This change appeared to coincide with the onset of nitrogen limitation. Other nitrogenous osmolytes were produced in five of the six species but in much smaller quantities. DMSP contributed significantly to cellular sulfur throughout the growth cycle although, in some algae, the proportion of dissolved DMSP increased substantially during stationary growth. When present, GET formed a sizeable fraction of the cellular nitrogen only during exponential growth. A significant percentage (ca. 50%) of the organic nitrogen could not be accounted for even when cellular pools of protein, amino acids, inorganic nitrogen, and nitrogenous osmolytes were combined. Based on these experiments, there does not appear to be a reciprocal relationship between DMSP and GET production, although GET production does appear to be correlated with nitrogen availability.