MICROBIAL ECOLOGY OF THE CARIACO BASIN'S REDOXCLINE: THE U.S.-VENEZUELA CARIACO TIMES SERIES PROGRAM
MICROBIAL ECOLOGY OF THE CARIACO BASIN'S REDOXCLINE: THE U.S.-VENEZUELA CARIACO TIMES SERIES PROGRAM
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加里亚科盆地氧化还原素的微生物生态：美国-委内瑞拉加里亚科时代系列计划
DOI：
10.1007/1-4020-4297-3_18
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发表时间：
2006
影响因子：
4.4
通讯作者：
M. Scranton
中科院分区：
文献类型：
--
作者：
G. Taylor;Maria Iabichella;R. Varela;Xueju Lin;M. Scranton
合作的美国-委内瑞拉CARIACO计划（Carbon Retention I nA Colored Ocean）已开始阐明Cariaco盆地氧化还原跃层的微生物生态学。这种缺氧的水柱支持高度分层的原核生物，原生动物和病毒的微生物组合，表现出丰富的和活性的最大值附近的O2/H2S界面。在好氧层中，微异养生物的丰度和活性每年变化的程度相同（16至20倍）的初级生产者在上75-100米，但相位。在氧化还原跃层和缺氧层中，这些相同的变量与表面生产的关系并不明显。氧化还原跃层内的异养碳需求超过了来自混合层的下沉有机物的输送。Cariaco的氧化还原跃层似乎是由微需氧和厌氧化学自养生物，如e-变形菌，其代谢是由无机化学梯度和运输控制。时间序列数据表明，原核生物，原生动物和病毒的分布和活动概况不同，在响应彼此和波动的接口的位置。原核生物量的氧化还原的快速周转推导出常年存在的食菌原生动物和病毒社区。化能自养生产足以支持异养对氧化还原圈内减少碳的需求，并为总原核生物群落产生合理的比增长率，平均在0.4和0.6 d −1之间。然而，和解的微生物对能源和氧化剂的需求与供应是不可能的经典的1-D垂直模型的Cariaco，仍然是最大的挑战之一，了解缺氧水柱的微生物生态一般。
The cooperative U.S.-Venezuela CARIACO program (CArbon Retention I nA Colored Ocean) has begun to elucidate the microbial ecology of the Cariaco Basin's redoxcline. This anoxic water column supports highly stratified microbial assemblages of prokaryotes, protozoa and viruses, exhibiting abundance and activity maxima near the O2/H2S interface. In the oxic layer, abundance and activity of microheterotrophs vary annually to the same extent (16 to 20-fold) as primary producers in the upper 75-100 m, but out of phase. In the redoxcline and anoxic layer, relationships of these same variables to surface production are not readily apparent. Heterotrophic carbon demands within the redoxcline exceed delivery of sinking organic matter from the mixed layer. The Cariaco's redoxcline appears to be inhabited by microaerophilic and anaerobic chemoautotrophs, such as e-proteobacteria, whose metabolism is controlled by inorganic chemical gradients and transport. Time series data demonstrate that distribution and activity profiles of prokaryotes, protozoa and viruses vary in response to one another and to fluctuations in the interface's position. Rapid turnover of prokaryotic biomass in the redoxcline is deduced from the perennial presence of bacterivorous protozoan and viral communities. Chemoautotrophic production is sufficient to support heterotrophic demand for reduced carbon within the redoxcline and yields reasonable specific growth rates for total prokaryotic communities, averaging between 0.4 and 0.6 d −1 . However, reconciliation of microbial demand for energy and oxidants with supply is not possible applying the classic 1-D vertical model to the Cariaco and remains one of the greatest challenges to understanding the microbial ecology of anoxic water columns in general.