Biogeochemical significance of attached and free-living bacteria and the flux of particles in the NE Atlantic Ocean
Biogeochemical significance of attached and free-living bacteria and the flux of particles in the NE Atlantic Ocean
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大西洋东北部附着和自由生活的细菌以及颗粒通量的生物地球化学意义
DOI：
10.3354/meps115191
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
P. Mackie
中科院分区：
文献类型：
--
作者：
C. Turley;P. Mackie
在东北大西洋在1990年5月，一个时期的高聚集体丰度，无定形聚集体包含的细菌，蓝藻和鞭毛虫的浓度大大高于周围的海水。那些从45至55米，在聚集体最大值的季节性温跃层之下，含有2.1至25.4 × 106细菌，1.0至4.7 × 106蓝藻和1.3至33.0 × 106鞭毛虫ml-1聚集体。附着在聚集体上的细菌的亮氨酸掺入率范围为12至206 × 10- 1 m01细胞-d。与粪便颗粒相关的细菌浓度通常高于无定形聚集体上的浓度。附着在聚集体上的细菌分别相当于10%和14%的自由生活的细菌碳通过水柱整合到100和300 m。如果考虑到附着和自由生活的细菌的碳含量不同，这可能会上升到25%和34%。然而，本次研究与西南150 km处测得的最大海洋雪浓度相吻合，因此在其他海洋雪浓度较低的时间，附着细菌的比例会较少，在顶部100和300 m处，附着细菌对细菌总产量的贡献在1.8 - 3.4%之间。自由生活的细菌碳对悬浮的POC（颗粒有机碳）的贡献在25%至33%之间，并且在校正它们在玻璃纤维过滤器上的保留后，该贡献可以是28%至40%。通量研究在1989年和1990年表明，一个较小的比例POC通量（9%）和细菌碳通量（10%）达到3100米比质量通量（25%和35%），表明有涉及的过程，优先利用或减少POC和细菌成分。从沉降颗粒中分离的细菌每年可贡献2.4%的综合细菌生物量. 1989年47月，在47”N，20°W，150 ~ 3100 m之间损失的汇~ng POC可能是中/深水细菌种群的重要碳源，能够提供约90%的细菌碳需求。在较深的沃茨，在600和3100米之间，有足够的深度消散下沉POC潜在地供应细菌的碳需求。然而，在600米以上，需要额外的有机碳源来支持它们的生长。
In the NE Atlantic during May 1990, a period of high aggregate abundance, amorphous aggregates contained substantially higher concentrations of bacteria, cyanobacteria and flagellates than the surrounding seawater. Those from 45 to 55 m, at the aggregate maximum just below the seasonal thermocline, contained 2.1 to 25.4 X 10' bacteria, 1.0 to 4.7 X 10' cyanobacteria and 1.3 to 33.0 X 106 flagellates ml-' aggregate. Leucine incorporation rates by bacteria attached to aggregates ranged from 12 to 206 X 10-*' m01 cell-' d' The concentration of bacteria associated with faecal pellets was generally higher than the concentration on the amorphous aggregates. Bacteria attached to aggregates were equivalent to 10 and 14 % of free-living bacterial carbon integrated through the water column to 100 and 300 m, respectively. This could rise to 25 and 34% if the different carbon content of attached and free-living bacteria was taken into account. However, this study coincided with the maximum marine snow concentration measured 150 km southwest, so at other times when marine snow concentrations are lower, the proportion of attached bacteria will be less. The contribution of attached bacteria to total bacterial production in the top 100 and 300 m ranges between 1.8 and 3.4 %. The contribution of free-living bacterial carbon to suspended POC (particulate organic carbon) was between 25 and 33% and after correcting for their retention on the glass fibre filters, this contribution could be 28 to 40%. Flux studies during 1989 and 1990 indicated that a smaller proportion of POC flux (9 %) and bacterial carbon flux (10%) reached 3100 m than mass flux (25 and 35%), indicating there are processes involved which preferentially utilise or reduce the POC and bacterial components. Bacterial detachment from sinking particles could contribute 2.4 % of the integrated bacterial biomass per annum. The fraction of sink~ng POC lost between 150 and 3100 m may be an important carbon source to the mid/deep-water bacterial population, capable of supplying around 90% of the bacterial carbon demand during April to July 1989 at 47" N, 20°W. In the deeper waters, between 600 and 3100 m, there was sufficient depth-dissipated sinking POC to potentially supply the carbon demand of the bacteria. However, above 600 m an additional source of organic carbon is required to support their growth.