ISSN:
1573-5117
Keywords:
water bloom
;
picoplankton
;
Synechococcus
;
phycoerthrin
;
phycocyanin
;
absorption spectra
;
fluorescence spectra
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Unicellular autofluorescent picoplankton ranging from 0.4 to 1.5 µm in diameter were found to be a significant component of phytoplankton in the North Basin of Lake Biwa during early summer in 1989 and 1990. The abundance of these picoplankton varied seasonally by about three orders of magnitude with one maximum of up to 106 cells ml−1. Bloom-forming picoplankton were isolated by dilution and further cultivated in liquid medium. Three clones were found to be representative species of the bloom. Using epifluorescence and electron microscopy as well as absorption and fluorescence emission spectroscopy, we examined these clones according to shape and pigment composition. They have ringlike thylakoids, are photosynthetically active and have no nuclear envelope. The cyanobacterial clones isolated represent three types containing phycobilisomes with either phycocyanin or phycoerthrin as the dominant accessory pigment. They are described here as three new species, two phycoerythrin-rich types and one phycocyanin-rich type, all of them belonging to the Synechococcus group. The differences found by fluorescence emission of isolated clones are discussed with respect to in situ strain identification.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00006077
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