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The Role of Grazing on Bacteria in Plankton Succession

1989; Springer Nature; Linguagem: Inglês

10.1007/978-3-642-74890-5_9

1432-0061

Hans Güde,

Protist diversity and phylogeny

As has been pointed out in Chapter 1, the planktonic community is especially suitable for testing general ecological theories. Its spatial structure is relatively simple, and many species can be easily cultured and have short generation times. An experimental approach can be effective, particularly with those plankton showing the highest potential growth rates: the bacteria. Indeed, many important biotic interactions such as competition, commensalism, mutualism, predation, and parasitism have been studied using bacteria (Frederickson, 1977). In spite of this wealth of experimental data, however, there is no consensus regarding the control of planktonic bacterial succession. This lack of agreement is not surprising considering the inability of current methodologies to clearly distinguish different populations of bacteria. The information gained from microscopic examination of bacteria is limited, unlike the case for phyto- and zooplankton. Bacterial composition can at best be differentiated according to rough morphologic criteria such as length and width of cells, multicellular or single-celled growth, attachment to surfaces, etc. The indirect approach of analyzing the composition of colonies grown on agar plates is hindered by the large discrepancy between plate counts and direct microscopic counts (Staley and Konopka, 1985). As has been emphasized by Pedros-Alio (see Chapter 8), promising approaches based on species-specific biomolecular cues may improve this situation in the near future.