Plankton Ecological Processes in Subtropical-Shelf Ecosystems-- Carbon Flux of Bacteria in Microbial Loop(I)

瀏覽統計 Email 通知 RSS Feed

Information

Details

Project title

Translated Name/計畫中文名

子計畫：副熱帶陸棚浮游生物食物網生態過程研究--微生物環細菌生物量傳遞過程(I)

Project Coordinator/計畫主持人

An-Yi Tsai

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Institute of Marine Environment and Ecology

Website

https://www.grb.gov.tw/search/planDetail?id=12678739

Year

2018

Start date/計畫起

01-08-2018

Expected Completion/計畫迄

31-07-2019

Bugetid/研究經費

1087千元

ResearchField/研究領域

海洋科學

在海洋環境中基礎生產力約有50%的有機碳經同化作用被異營性細菌所利用.而異營性細菌則是扮演著控制微生物環之能量及物質循環的重要角色,據研究了解到異營性細菌的生產量是受到生物及非生物因子所影響. 非生物因子包括溫度,鹽度及有機物質的利用(bottom-up control). 而生物因子則透過原生動物的攝食與病毒裂解(top-down control)的過程而有效控制異營性細菌的生產量.在能量的傳遞上,細菌如被原生動物攝食會將能量往上一階傳遞,如細菌被病毒所裂解其微生物環的能量會繼續在水體中循環,進而快速地被異營性細菌所利用.因此了解原生動物的攝食與病毒裂解的重要性,可讓我們更深入探討水體中能量流動的方向.本研究的海域---東海南部位於西北太平洋的西部邊緣海域,其中除大陸閩江水會注入陸源性物質及營養鹽會影響此海域物理化學與生物空間變化外,尚還有來自東海東邊貧養鹽之黑潮水，入侵東海南邊的台灣暖水與湧升流水域.直到現在,對現今的研究而言,在東海南部海域環境中病毒與微細鞭毛蟲攝食對細菌數量及能量傳遞的影響尚未有完整的資料報導過. 本研究計畫的目的則是希望利用修正後之稀釋培養法(modified dilution method)同時測量到病毒與上階攝食者(如微細鞭毛蟲)對東海海洋不同生態環境中之細菌生產量所產生的影響,據此可進一步了解病毒與原生動物攝食者對東海南部海域之細菌所扮演的生態角色. Heterotrophic bacteria assimilate a significant fraction of the primary production (approximately 50%) in marine environments. Bacterial production is dependent on both abiotic and biotic factors. Abiotic factors (bottom-up control) include temperature, salinity and substrate availability. The biotic factors (top-down control) that may control bacterial production in aquatic systems are predation by protists as well as viral infection and lysis. When bacterial cells are grazed, energy is made available to higher trophic levels, whereas when they are lysed, organic carbon and nutrients are dissolved and bacterial carbon is recycled as bacterial production in a closed loop. Therefore, it is important to estimate both viral- and grazing-induced bacterial mortality to obtain better insight into the forces underlying nutrient flow within an aquatic food web. The East China Sea (ECS) is located on the western edge of the Northwest Pacific Ocean, in addition to freshwater input from Minjiang River, the Kuroshio Water (KW) coming from the western equatorial Pacific in the east and Taiwan Current Warm Water (TCWW) from the south and upwelling area. To date, no studies have investigated the effect of viral-mediation of bacterial production in the ECS. In this study, we estimated grazing and viral mortality of bacteria with the used of the modified dilution approach to compare the relative contributions of viral lysis and nanoflagellate grazing on bacterial mortality and explore the variation in these loss factors in the ECS.

Keyword(s)

細菌
微細鞭毛蟲
病毒
微生物循環圈
bacteria
nanoflagellate
viruses
microbial loop

DSpace CRIS

Plankton Ecological Processes in Subtropical-Shelf Ecosystems-- Carbon Flux of Bacteria in Microbial Loop(I)

Details

Description