Production of extracellular polymeric substances (EPS) by benthic diatoms: effect of irradiance and temperature
Production of extracellular polymeric substances (EPS) by benthic diatoms: effect of irradiance and temperature
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DOI：
10.3354/meps236013
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发表时间：
2002-07
影响因子：
2.5
通讯作者：
K. Wolfstein;L. Stal
中科院分区：
文献类型：
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作者：
K. Wolfstein;L. Stal
采用无菌培养的新月藻和自然底栖硅藻群落，研究了温度和光照对新月藻胞外聚合物（EPS）产生的影响。在培养过程中，结果取决于藻类的生长阶段以及是否考虑绝对值或生物量相关值。在15 ° C和25°C下，在早期稳定生长期产生最高量的EPS（现存量）。当EPS浓度被归一化为叶绿素a（chl a）时，在4 ° C和10°C下测量到最大值。独立的温度的比率（EPS：叶绿素a）随着年龄的增长的文化。此外，在较古老的文化中，所研究的温度之间的差异不太明显。以野外底栖硅藻样品为材料，研究了温度和光照对EPS初级生产和排泄的综合影响，以及利用14C掺入法研究了光合固定碳（C）在细胞内外C库中的分配.在25°C下测得初级生产和EPS（生产率）的最高值。在较低光照下，35 °C对各组分的产率均有抑制作用。在培养物中以及在天然样品中，在不同温度下以不同量产生与细胞紧密结合的EPS部分（附着的EPS）和可溶性部分（胶体EPS）。这表明，EPS的2个操作定义部分的生产可能具有不同的功能，例如用于迁移或用于储备产品的储存。
An axenic culture of Cylindrotheca closterium and a natural community of benthic diatoms were used to study the effect of temperature and irradiance on the production of extracellu- lar polymeric substances (EPS). In the culture, results depended on the growth stage of the algae and on whether absolute values or biomass-related values were considered. The highest amount of EPS (standing stock) was produced at 15 and 25°C during early stationary growth phase. When EPS con- centrations were normalized to chlorophyll a (chl a), maximum values were measured at 4 and 10°C. Independent of temperature the ratios (EPS:chl a) decreased with increasing age of the culture. Addi- tionally, differences between the investigated temperatures were less pronounced in older cultures. A field sample of benthic diatoms was used to study: (1) the combined effect of temperature and irra- diance on primary production and excretion of EPS; and (2) the partitioning of photosynthetically fixed carbon (C) into different fractions of intracellular and extracellular C pools by using a short- term 14 C incorporation. Again highest values of primary production and EPS (production rates) were measured at 25°C. At lower irradiances, the temperature of 35°C had an inhibitory effect on the pro- duction rates of all fractions. In the culture as well as in the natural sample, the fraction of EPS that was closely bound to the cells (attached EPS) and the soluble fraction (colloidal EPS) were produced in different amounts at the different temperatures. This suggested that the production of the 2 oper- ationally defined fractions of EPS might serve different functions, e.g. for migration or for storage of reserve products.