台湾海峡南部海域好氧不产氧光合异养细菌对上升流的响应

Response of aerobic anoxygenic phototrophic bacteria to upwelling in the southern Taiwan Strait of China

国内外关于好氧不产氧光合异养细菌(AAPB)和上升流之间关系的研究甚少。本文采用“基于蓝细菌校正的时序红外显微技术”研究了台湾海峡南部近岸上升流中心区AAPB对上升流变化的响应。研究结果发现,在上升流涌升的初始阶段,AAPB和总异养细菌丰度较低;随着上升流的发展,两者丰度均增加并在上升流的成熟期达到最高值;而当上升流衰退时,AAPB和总异养细菌丰度开始下降。在上升流发展过程中,AAPB丰度与叶绿素a浓度在一定范围内呈显著正相关,但同时受环境低磷浓度的限制,总异养细菌丰度与氮、磷、硅营养盐均有显著正相关,表明叶绿素a指示的浮游植物所释放的溶解有机碳和环境中的磷限制可能对AAPB起着更为直接和重要的作用,而营养盐则可能在总异养细菌对上升流的响应中起着重要作用。本研究有助于我们理解AAPB在碳及其他生源要素循环中的作用及其调控机制。

There is little information about the relationship between aerobic anoxygenic photoheterotrophic bacteria(AAPB)and upwelling.In this work,the response of AAPB to upwelling in the southern Taiwan Strait was examined,using the“Time-series observation-based cyanobacteria-calibrated InfraRed Epifluorescence Microscopy,TIREM”.The results showed that in the initial stage of upwelling,the abundances of AAPB and total heterotrophic bacteria were low;with the development,their abundances both increased and reached the highest value at the mature stage of upwelling;notably,when the upwelling declined,they began to decrease.During the developmental process of upwelling,AAPB abundance was positively correlated with chlorophyll a concentration in a certain range,and limited by low phosphorus concentration,while total heterotrophic bacteria abundance was positively correlated with nitrogen,phosphorus and silicon nutrients concentration,suggesting that dissolved organic carbon released by phytoplankton and phosphorus limitation might play a more direct and important role in AAPB,while nutrients probably acted as an important role in the response of total heterotrophic bacteria to upwelling.This study will help to better understand the unique role of AAPB in the biogeochemical cycle of carbon and other biogenic elements.