A novel niche for Prochlorococcus sp in low-light suboxic environments in the Arabian Sea and the Eastern Tropical North Pacific
A novel niche for Prochlorococcus sp in low-light suboxic environments in the Arabian Sea and the Eastern Tropical North Pacific
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DOI：
10.1016/s0967-0637(99)00108-9
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发表时间：
2000-07-01
影响因子：
2.4
通讯作者：
Shalapyonok, A
中科院分区：
文献类型：
--
作者：
Goericke, R;Olson, RJ;Shalapyonok, A
海洋原绿球藻存在于所有热带和亚热带海洋，在那里它经常被发现在整个真光层，大大有助于浮游植物生物量和初级生产，并以与其他微生物相当的速度增长。显然，原绿球藻和真核微微型浮游生物在开阔海洋中共享重要的生态位。在这里，我们报告发现的原绿球藻种群在阿拉伯海和墨西哥热带北太平洋东部的氧气最低区的oxyclines下面的层。这些种群的不寻常之处在于，这些有时是在80至140米深度发现的虚拟单藻培养物，通常低于真光区，其中辐照度范围为表面辐照度（I（o））的0.1至2%。这些深层种群的色素补充物被详细表征，以前未鉴定的原绿球藻的Chl-c样色素是Mg-3，8-二乙烯基脱镁卟啉a（5）单甲酯，这些深层中群体的类胡萝卜素补充类似于培养的原绿球藻菌株的类胡萝卜素补充，除了高浓度的玉米黄质的7 '，8'-二氢衍生物，很可能是副黄质，即使这些群体中色素的细胞浓度非常高，表明对低辐照的适应，阿拉伯海中这些种群所经历的环境光，
Prochlorococcus marinus is present in all tropical and subtropical oceans, where it is often found throughout the euphotic zone, contributing significantly to phytoplankton biomass and primary production and growing at rates comparable to those of other picoplankters. Clearly, Prochlorococcus and eucaryotic picoplankton share significant niche dimensions in the open ocean. Here we report the discovery of populations of Prochlorococcus in layers below the oxyclines of the oxygen minimum zones of the Arabian Sea and the Eastern Tropical North Pacific off Mexico. The unusual aspects of these populations are that these were at times virtual monoalgal cultures found at a depth of 80 to 140 m, often below the euphotic zone, where irradiance ranged from less than 0.1 to 2% of the surface irradiance (I(o)), The pigment complement of these deep populations was characterized in detail, The previously unidentified Chl-c-like pigment of Prochlorococcus is Mg-3,8-divinylpheoporphyrin a(5) monomethylester, The carotenoid complement of populations in these deep layers was similar to that of cultured Prochlorococcus strains, except for high concentrations of a 7',8'-dihydro-derivative of zeaxanthin, quite likely parasiloxanthin, Even though cellular concentrations of pigments were very high in these populations, suggesting acclimation to low irradiance, ambient Light experienced by these populations in the Arabian Sea,