Wide-ranging abundances of aerobic anoxygenic phototrophic bacteria in the world ocean revealed by epifluorescence microscopy and quantitative PCR
Wide-ranging abundances of aerobic anoxygenic phototrophic bacteria in the world ocean revealed by epifluorescence microscopy and quantitative PCR
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DOI：
10.4319/lo.2005.50.2.0620
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发表时间：
2005-03-01
影响因子：
4.5
通讯作者：
Fuhrman, JA
中科院分区：
文献类型：
--
作者：
Schwalbach, MS;Fuhrman, JA
有报道称，含有细菌叶绿素a （BChla）的好氧无氧光养细菌（AAnPB）占海水中细菌细胞总数的10%或更多，这促使我们利用红外荧光显微镜（IREM）和定量聚合酶链反应（QPCR）对南加州海岸15公里附近的当地水域和全球18个地点的AAnPB丰度进行了量化。在2001年4月至9月期间，iremb估计的AAnPB占南加州光带细菌总数的1.66% +/- 0.55%（平均+/- SD）。AAnPB的IREM计数需要谨慎解释，因为检测灵敏度问题和叶绿素a和细菌叶绿素a在波长> - 850 nm的自身荧光之间的重叠。在2001年1月至2003年7月期间，qpcr估计的AAnPB占南加州海岸5米深度细菌总数的1.17% +/- 1.56%（假设一个pufM基因细胞（-1）和2.5 fg总DNA细胞（-1））。在热带至极地水域对AAnPB进行的全球QPCR调查显示，在大多数调查的海洋环境中，AAnPB的估计值很低（<总细菌计数的2.5%），但在长岛湾和切萨皮克湾的河口水域中，AAnPB的估计值为10%。在大多数海洋系统中，AAnPB丰度比以前报道的东太平洋低，这表明AAnPB丰度比以前认识到的变化更大。我们的研究结果并不支持AAnPB在贫营养环境中更丰富的观点，事实上，结果恰恰相反。这些结果提出了一个问题，即有氧无氧光合作用在海洋生态系统中的优势。
Reports that aerobic anoxygenic phototrophic bacteria (AAnPB) containing bacteriochlorophyll a (BChla) constitute 10% or more of total bacteria cell counts in seawater prompted us to quantify AAnPB abundances in local waters 15 kin off the coast of Southern California and at 18 sites around the globe using infrared epifluorescent microscopy (IREM) and quantitative polymerase chain reaction (QPCR). IREM-estimated AAnPB comprised 1.66% +/- 0.55% (mean +/- SD) of total bacterial counts in the euphotic zone between April and September 2001 off Southern California. IREM counts of AAnPB need to be interpreted with caution due to detection sensitivity concerns and overlap between chlorophyll a and bacteriochlorophyll a autofluorescence at wavelengths > 850 nm. QPCR-estimated AAnPB were 1.17% +/- 1.56% of total bacteria counts at 5-m depth between January 2001 and July 2003 off the coast of Southern California (assuming one pufM gene cell(-1) and 2.5 fg total DNA cell(-1)). Global QPCR surveys of AAnPB conducted in tropical to polar waters yielded low estimates (< 2.5% of total bacteria counts) of AAnPB in most marine environments surveyed, but estimates > 10% were observed in estuarine waters of Long Island Sound and Chesapeake Bay. AAnPB abundances are lower in most marine systems than previously reported from the Eastern Pacific and demonstrate that AAnPB abundances are more variable than previously realized. Our results do not support the notion AAnPB are more abundant in oligotrophic environments and, in fact, suggest the opposite. These results raise questions about where aerobic anoxygenic photosynthesis is advantageous in marine ecosystems.