春夏季貧營養黑潮海域浮游細菌群聚組成之變化

細菌群聚結構的呈現是與其它生物及自然環境間交互作用的結果，本研究為探究春、夏季貧營養鹽黑潮海域於不同季節及其伴隨的氣象擾動所引發的效應，對此海域的物理、化學水文和生物相關參數所造成之改變，及上述因子可能對浮游細菌群聚組成的影響。研究主要利用2008年三月至七月共計四次航次於黑潮固定測站 (123°10’ °E；25° 5’ °N)進行。結果顯示本水體於春、夏季皆處於無機氮鹽限制的環境 (N/P ratio=3.52~6.02)，細菌群聚結構組成不論時節與空間 (表水與50 m水樣)皆以泛菌屬 (Pantoea)為大宗，其次為遠洋桿菌屬 (Pelagibacter)。然而若就代表生物多樣性的細菌歧異度指數 (Shannon; H')及均勻度指數 (Evenness; E)進行分析，皆呈現春季高 (H'：2.61~3.11；E：0.48 ~0.72)、夏季低 (H'：1.87；E：0.32)的趨勢；細菌歧異度指數中的單套基因型歧異度 (haplotype diversity，Hd)與核苷酸歧異度 (nucleotide diversity，π)也皆呈現春季 (Hd：0.87~0.95；π：0.34~0.70)高於夏季 (Hd：0.67；π：0.20)的趨勢，唯有優勢度指數 (Simpson; D)呈現夏季高 (0.34)、春季低 (0.06~0.14)的現象，說明春季水體有較高的細菌物種豐富度及遺傳歧異度，而夏季水體則有明顯優勢種存在。此外，表水Shannon指數與無機氮鹽 (DIN)有一相似之變化趨勢，推測春季較頻繁且劇烈的氣象擾動事件提高水體中無機營養鹽濃度，舒緩細菌生長的限制，可能是使春季水體細菌物種豐富度提升的原因之一；而夏季氣候狀態穩定，營養鹽的供應逐漸匱乏，細菌物種豐富度隨著物種彼此間的競爭而下降，此時泛菌屬 (Pantoea)的比例甚至超過50 %，推測可能是因泛菌屬 (Pantoea)具固氮能力，且夏季的高溫接近其最適生長溫度，使其在高溫且營養鹽貧乏的黑潮海域更具競爭優勢。

關鍵字

黑潮；浮游細菌群聚

並列摘要

The purpose of this study is to understand (a) the spatial (i.e., vertically) and temporal variations and (b) the potential regulatory factors that effected on species composition of bacterioplankton in the oligotrophic Kuroshio Water. Samples were collected on board R/V Ocean Research I and II at station (123°10’ °E；25° 5’ °N) in the Kuroshio Water in March, April and July, 2008. Results showed that the N:P molar ratio ranged within 3.52~6.02, and it suggested that growth of bacterioplankton was N-limited during study period. As for bacterioplankton composition, it was dominated by Pantoea and following by Pelagibacter, either in temporal (spring vs. summer) and spatial (surface vs. 50 m) scales. Seasonally, the indexes of Shannon (H' : 1.87~3.11), Evenness (E : 0.32~0.72), haplotype diversity (Hd : 0.67~0.95), and nucleotide diversity (π：0.20~0.70) were however higher in spring than that in summer with exception of Simpson (D : 0.14~0.34). The results indicated that both species abundance and genetic diversity of bacterioplankton were higher in spring, but it was mostly dominated by Pantoea in summer. Further analyses suggested that higher species abundance of bacterioplankton in spring might be due to relaxation of growth competition in water column with higher nutrient concentration, e.g., DIN, caused by physical disturbance. In opposite, the species abundance of bacterioplankton was low when inorganic nutrient was depleted in summer. It, however, may favor the growth of Pantoea, the dominant species, with the ability of nitrogen-fixation and higher optimum growth temperature in warm summer.

並列關鍵字

無資料

參考文獻

林陳彥 (2005) 以16S rDNA分子技術探討薄膜生物反應器處理ABS廢水之硝化

in situ detection of individual microbial cells without cultivation. Microbiological

Reviews 59 (1): 143-169.

deposition of nutrients to the Atlantic Ocean. Biogeochemistry 35: 27-73.

diversity in two coastal lagoons deduced from 16S rDNA PCR ampliﬁcation and

延伸閱讀

Tsai, A. Y., Chiang, K. P., Shiah, F. K., Hung, J. J., & Chao, C. F. (2009). Picoplankton及nanoflagellates在熱帶富營養鹽瀉湖環境之季節變化與其水體狀態及上階攝食者之關係. 臺灣水產學會刊, 36(2), 135-150. https://doi.org/10.29822/JFST.200906.0004
Chen, H. Y., & Chen, Y. L. L. (1992). 臺灣東北湧升流海域夏季表層網採浮游動物之數量與品質. Terrestrial, Atmospheric and Oceanic Sciences, 3(3), 321-334. https://www.airitilibrary.com/Article/Detail?DocID=10170839-199209-3-3-321-334-a
李晃銘（2004）。能生長於TCBS平板培養基的沿岸海水中細菌多樣性之探討〔碩士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU.2004.01756
Rajaram, G., Manivasagan, P., Thilagavathi, B., & Saravanakumar, A. (2010). Purification and Characterization of a Bacteriocin Produced by Lactobacillus lactis Isolated from Marine Environment. Advance Journal of Food Science and Technology, 2(2), 138-144. https://www.airitilibrary.com/Article/Detail?DocID=20424876-201003-201009060053-201009060053-138-144
李韋慶（2009）。Isolation and Characterization of a Bacteriophage of Klebsiella pneumoniae from Water〔碩士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU.2009.01772

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春夏季貧營養黑潮海域浮游細菌群聚組成之變化

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