Bacterial contributions to formation of transparent exopolymer particles (TEP) and seasonal trends in coastal waters of Sagami Bay, Japan
Bacterial contributions to formation of transparent exopolymer particles (TEP) and seasonal trends in coastal waters of Sagami Bay, Japan
复制标题
DOI：
10.3354/ame046031
复制
发表时间：
2007-01
影响因子：
1.4
通讯作者：
Kugako Sugimoto;H. Fukuda;M. Baki;I. Koike
中科院分区：
文献类型：
--
作者：
Kugako Sugimoto;H. Fukuda;M. Baki;I. Koike
在海水培养实验中，使用从日本相模湾地表水获得的滤液（0.8 µm），评估了细菌形成透明外聚合物颗粒（TEP）的季节性趋势。使用阿辛蓝染色/比色法评估存在和不存在细菌代谢抑制剂的样品。在代谢抑制剂的存在下，TEP的形成总是可以忽略不计的。然而，与细菌生长相关的TEP积累速率（t = 0至1）在9月、10月和3月高（156.9 ± 66 μg黄原胶当量l-1 d-1），而在9月、10月和3月低（0 ± 12.7 μg黄原胶当量l-1 d-1）。l-1 d-1），即使对于细菌数量大量增加的样品。在没有代谢抑制剂的情况下，TEP的累积速率与叶绿素a浓度（r = 0.799，n = 9）、细菌有机碳产生速率（r = 0.784，n = 9）和细菌数量（r = 0.948，n = 9）呈正相关，表明浮游植物分泌物的重要性，可能也来自细菌。在TEP形成率高的月份期间，以碳形式形成的细菌TEP超过细菌碳利用率1至2倍，表明细菌TEP形成的间接过程。根据海水培养物和现场样品的显微镜检查，清除TEP前体增加的细菌颗粒是重要的细菌增强高TEP形成在秋季和早春。这些观察结果表明细菌作为细菌相关TEP形成的介质的重要性，其与可用的溶解有机物（包括TEP前体）的供应相结合。
Seasonal trends in the bacterial formation of transparent exopolymer particles (TEP) were assessed in a seawater culture experiment using filtrate (0.8 µm) obtained from surface water of Sagami Bay, Japan. An Alcian blue staining/colorimetric method was used to assess samples in both the presence and absence of metabolic inhibitors of bacteria. TEP formation was always negligible in the presence of metabolic inhibitors. However, the TEP accumulation rate (t = 0 to 1) associated with bacterial growth was high (156.9 ± 66 µg Gum Xanthan equivalents l -1 d -1 ) in September, October, and March, and low (0 ± 12.7 µg Gum Xanthan equiv. l -1 d -1 ) from December to February, even for samples with large increases in bacterial numbers. The observed TEP accumulation rate without metabolic inhibitors was positively correlated with chlorophyll a concentration (r = 0.799, n = 9), bac- terial organic carbon production rate (r = 0.784, n = 9), and bacterial number (r = 0.948, n = 9) in the field, indicating the importance of exudates from phytoplankton and probably from bacteria. During the months with high TEP formation rates, the bacterial TEP that formed in terms of carbon exceeded bacterial carbon utilization by 1- to 2-fold, suggesting an indirect process of bacterial TEP formation. Based on microscopic examinations of seawater cultures and field samples, the scavenging of TEP precursors by increased bacterial particles was important in the bacterial enhancement of high TEP formation in fall and early spring. These observations suggest the importance of bacteria as media- tors of bacteria-associated TEP formation coupled to the supply of usable dissolved organic matter, including TEP precursors.