Fuhrman Jed A
Department of Biological Sciences, University of Southern California, Los Angeles 90089-0371, USA.
Antonie Van Leeuwenhoek. 2002 Aug;81(1-4):521-7. doi: 10.1023/a:1020513506777.
Molecular biodiversity studies of microbial communities have provided invaluable information on the existence of heretofore unknown organisms and on community composition. Cloning and 'fingerprinting' techniques have been used many times to study prokaryote community composition of marine plankton. There are still many opportunities for new discoveries in this area, but the results have also opened new questions about the activities of these organisms and their function, going beyond just listing taxa or counting organisms. Rarely can the broad function be inferred from phylogenetic position alone (e.g. cyanobacteria). The recent discovery of abundant non-cyanobacterial marine phototrophs points to our inability to link phylogenetic position with function in a detailed way. One approach we have found fruitful is to combine fluorescence in situ hybridization with microautoradiography, a technique dubbed STARFISH. A recent application has shown that ubiquitous archaea from the deep sea, phylogenetically related to extreme thermophiles, are active in the uptake of amino acids from ambient (nanomolar) concentrations. This suggests the group is at least partly heterotrophic and able to compete successfully with bacteria for nutrients. Other as-yet uncultivated groups are also amenable to similar studies.
微生物群落的分子生物多样性研究为迄今未知生物的存在及群落组成提供了宝贵信息。克隆和“指纹识别”技术已多次用于研究海洋浮游生物的原核生物群落组成。该领域仍有许多新发现的机会，但研究结果也引发了关于这些生物的活动及其功能的新问题，而不仅仅是列出分类单元或计算生物数量。仅从系统发育位置（如蓝细菌）很少能推断出广泛的功能。最近发现大量非蓝细菌海洋光合生物表明我们无法详细地将系统发育位置与功能联系起来。我们发现一种富有成效的方法是将荧光原位杂交与微放射自显影相结合，这一技术被称为STARFISH。最近的一项应用表明，来自深海的普遍存在的古菌，在系统发育上与极端嗜热菌相关，能够从环境（纳摩尔）浓度中摄取氨基酸。这表明该类群至少部分是异养的，并且能够与细菌成功竞争营养物质。其他尚未培养的类群也适用于类似的研究。
