Regulation of bacterial growth rates by dissolved organic carbon and temperature in the equatorial Pacific Ocean
Regulation of bacterial growth rates by dissolved organic carbon and temperature in the equatorial Pacific Ocean
复制标题
DOI：
10.1007/s002489900003
复制
发表时间：
1997-01-01
影响因子：
3.6
通讯作者：
Rich, JH
中科院分区：
文献类型：
--
作者：
Kirchman, DL;Rich, JH
在赤道太平洋考察了溶解有机物（DOM）和温度对细菌生产的影响。此外，葡萄糖，葡萄糖加铵，或游离氨基酸刺激细菌生产（[H-3]胸苷掺入），而细菌丰度的变化可以忽略不计或远远小于细菌生产的变化。细菌的平均生长速率也大大增加DOM添加后，而相比之下，除了铵单独从来没有影响生产，细菌丰度，或生长速率。由于在以前的研究中没有观察到大的葡萄糖效应的冷海洋沃茨，进行了几个实验来检查DOM-温度的相互作用。这些实验表明，在较高的温度下，细菌对DOM的反应更快，反应程度更大，这可能解释了以前研究中明显矛盾的结果。我们还研究了温度如何影响糖吸收的动力学参数。葡萄糖和甘露糖的最大摄取速率（V-max）随温度升高而增加（Q（10）= 2.4），尽管半饱和常数（K-m）不受影响; K-m + S大致等于通过高压液相色谱技术测量的葡萄糖浓度（S）。细菌的生产和生长速率似乎是有限的DOM在赤道太平洋，因此细菌生产遵循初级生产在大的空间和时间尺度在这个海洋制度，已观察到在其他水生系统。尽管温度可能不会限制赤道太平洋和类似温暖沃茨中细菌的生长速率，但它仍然可能影响细菌对DOM供应变化的反应，并有助于设定稳态DOM浓度。
The effect of dissolved organic matter (DOM) and temperature on bacterial production was examined in the equatorial Pacific Ocean. Addition of glucose, glucose plus ammonium, or free amino acids stimulated bacterial production ([H-3]thymidine incorporation), whereas changes in bacterial abundance were either negligible or much less than changes in bacterial production. The average bacterial growth rate also greatly increased following DOM additions, whereas in contrast, addition of ammonium alone never affected production, bacterial abundance, or growth rates. Since the large glucose effect was not observed in previous studies of cold oceanic waters, several experiments were conducted to examine DOM-temperature interactions. These experiments suggest that bacteria respond more quickly and to a greater extent to DOM additions at higher temperatures, which may explain apparently conflicting results from previous studies. We also examined how temperate affects the kinetic parameters of sugar uptake. Maximum uptake rates (V-max) of glucose and mannose increased with temperature (Q(10) = 2.4), although the half-saturation constant (K-m) was unaffected; K-m + S was roughly equal to glucose concentrations (S) measured by a high pressure liquid chromographic technique. Bacterial production and growth rates appear to be limited by DOM in the equatorial Pacific, and thus bacterial production follows primary production over large spatial and temporal scales in this oceanic regime, as has been observed in other aquatic systems. Although temperature may not limit bacterial growth rates in the equatorial Pacific and similar warm waters, it could still affect how bacteria respond to changes in DOM supply and help set steady-state DOM concentrations.