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CYANOBACTERIAL BUOYANCY REGULATION: THE PARADOXICAL ROLES OF CARBON 1
Author(s) -
Klemer Andrew R.,
Cullen John J.,
Mageau Michael T.,
Hanson Kathryn M.,
Sundell Richard A.
Publication year - 1996
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.0022-3646.1996.00047.x
Subject(s) - biology , buoyancy , carbon fibers , ecology , mechanics , physics , materials science , composite number , composite material
In stratified lakes, dominance of the phytoplankton by cyanobacteria is largely the result of their buoyancy and depth regulation. Bloom‐forming cyanobacteria regulate the gas vesicle and storage polymer contents of their cells in response to interactive environmental factors, especially light and nutrients. While research on the roles of nitrogen and phosphorus in cyanobacterial buoyancy regulation has reached a consensus, evaluations of the roles of carbon have remained open to dispute. We investigated the various effects of changes in carbon availability on cyanobacterial buoyancy with continuous cultures of Microcystis aeruginosa Kuetz. emend. Elenkin (1924), a notorious bloom‐former. Although CO 2 limitation of photosynthesis can promote buoyancy in the short term by preventing the collapse of turgor‐sensitive gas vesicles and/or by limiting polysaccharide accumulation, we found that sustained carbon limitation restricts buoyancy regulation by limiting gas vesicle as well as polysaccharide synthesis. These results provide an explanation for the positive effects of bicarbonate enrichment on cyanobacterial nitrogen uptake and bloom formation in lake experiments and may help to explain the pattern of cyanobacterial dominance in phosphorus‐enriched, low‐carbon lakes.