| Project/Area Number |
23KF0015
|
|---|
| Research Category |
Grant-in-Aid for JSPS Fellows
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 外国 |
|---|
| Review Section |
Basic Section 63010:Environmental dynamic analysis-related
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
浜崎 恒二 東京大学, 大気海洋研究所, 教授 (80277871)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
BIKKINA POONAM 東京大学, 大気海洋研究所, 外国人特別研究員
|
|---|
| Project Period (FY) |
2023-04-25 – 2024-03-31
|
| Project Status |
Discontinued (Fiscal Year 2023)
|
| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2024: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2023: ¥1,200,000 (Direct Cost: ¥1,200,000)
|
|---|
| Keywords | 大気海洋相互作用 / 微生物 / エアロゾル |
|---|
| Outline of Research at the Start |
西部北太平洋において、海表面マイクロ層や海表面で発生するエアロゾルに含まれる有機酸の組成を明らかにすると共に、大気から海洋へのエアロゾル沈着に対する微生物群集の応答を明らかにすることを目的とする。学術研究船白鳳丸の航海に乗船し、亜寒帯、亜熱帯の観測定点に1週間滞在して海洋観測と大気観測を行う。海水及び大気のフィルターサンプルから脂質成分を抽出、ガスクロマトグラフ質量分析により有機酸組成を明らかにする。同時に、蛍光顕微鏡計数、16SrRNA遺伝子アンプリコンシーケンスによる菌相解析等により、微生物現存量と群集構造の変動を把握し、エアロゾル沈着に対する応答を明らかにする。
|
| Outline of Annual Research Achievements |
Seawater and aerosol samples were collected in the western North Pacific (WNP) during the KH23-3 cruise of RV Hakuho-maru in July 2023. We firstly analyzed the samples collected over the Bay of Bengal (BOB) and the southern Indian Ocean (SIO) during KH18-6 cruise to test methodological feasibility. To this date, rather sparse observations exist on bacterial characterization in the marine aerosols from the pelagic oceans, as is the case for WNP, BOB and SIO. Towards this, we conducted bacterial profiling in coarse and fine mode (<2.5 um cutoff) aerosol samples from the BoB and the SIO during late autumn. Over the BoB, Firmicutes dominated the abundance in coarse particles and are influenced by the terrestrial inputs from the Southeast Asia (i.e., evident from the back trajectories). Furthermore, bacterial communities over the SIO were found to be of marine origin and dominant phyla were totally different from those over the BoB. Alpha diversity revealed that bacterial communities in the coarse particles are somewhat complex than those in the fine mode. Notably, the beta diversity of the bacterial communities in the coarse and fine particles varied with the latitude. Our results highlight that prevailing terrestrial winds lead to the dominance of land derived bacteria which creates the regional differences in the long-range microbial exchange, especially in the coarse particles over the remote marine atmosphere.
|
