Occurrence and Ecological Significance of GTP in the Ocean and in Microbial Cells
Occurrence and Ecological Significance of GTP in the Ocean and in Microbial Cells
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GTP 在海洋和微生物细胞中的存在及其生态意义
DOI：
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发表时间：
1978
影响因子：
4.4
通讯作者：
David M. Karl
中科院分区：
文献类型：
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作者：
David M. Karl
基于峰高光发射值（0至3秒）和集成光通量测定（15至75秒）的各种海水样品的ATP浓度之间的比较表明，光检测的集成方法始终产生较高的ATP浓度，范围从1.38到2.35倍大于相应的峰值ATP值。观察到ΔADP曲线的显著相关性（r = 0.923）（即，积分的ATP -峰ATP）与GTP + UTP，表明对ATP测定的分析干扰是非腺嘌呤核苷酸三磷酸存在的结果。大小分级研究显示，在分析的最小大小级分（<10 μm）中，非腺嘌呤核苷酸三磷酸相对于ATP富集。对20种单细胞海藻进行了调查，以确定其细胞内核苷酸浓度，并将这些测定结果与海洋细菌Serratia marinorubra的实验室培养物中测得的水平进行比较。这些结果表明，S.海洋红藻的GTP/ATP比值与细胞生长速率成正比，细菌中的GTP/ATP比值比生长中的藻类大得多，这可能是由于细胞生物合成速率的差异。它的结论是定量测定GTP/ATP的比例在环境样品提取物中可能是有用的测量微生物的生长。
A comparison between the ATP concentrations based on peak height light emission values (0 to 3 s) and integrated light flux determinations (15 to 75 s) for a variety of seawater samples revealed that the integrated method of light detection consistently yielded higher ATP concentrations, ranging from 1.38 to 2.35 times larger than the corresponding peak ATP values. A significant correlation (r = 0.923) was observed for a plot of ΔADP (i.e., integrated ATP - peak ATP) versus GTP + UTP, suggesting that the analytical interference on the ATP assay was the result of the presence of non-adenine nucleotide triphosphates. Size-fractionation studies revealed an enrichment of the non-adenine nucleotide triphosphates, relative to ATP, in the smallest size fraction analyzed (<10 μm). Investigations were conducted with 20 species of unicellular marine algae to determine their intracellular nucleotide concentrations, and these determinations were compared to the levels measured in lab cultures of the marine bacterium Serratia marinorubra. These results indicated that the intracellular GTP/ATP ratios in S. marinorubra increase in direct proportion to the rate of cell growth, and that the GTP/ATP ratios in bacteria are much greater than in growing algae, presumably due to the differences in rates of cellular biosynthesis. It is concluded that quantitative determinations of GTP/ATP ratios in environmental sample extracts may be useful for measuring microbial growth.