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Changes in cellular components in a cyanobacterium ( Synechocystis aquatilis f. salina ) subjected to different N/P ratios—an ecophysiological study
Author(s) -
Nascimento Silvia Mattos,
De Oliveira e Azevedo Sandra Maria Feliciano
Publication year - 1999
Publication title -
environmental toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.813
H-Index - 77
eISSN - 1522-7278
pISSN - 1520-4081
DOI - 10.1002/(sici)1522-7278(199902)14:1<37::aid-tox7>3.0.co;2-r
Subject(s) - photosynthesis , chlorophyll a , cyanobacteria , biology , nutrient , biomass (ecology) , chlorophyll , botany , synechocystis , nitrate , hydrobiology , zoology , ecology , bacteria , genetics , aquatic environment
This paper describes the growth in culture of the cyanobacterium Synechocystis aquatilis f. salina . This organism was the dominant species over a 3 year period from October 1990 to August 1993 in the Barra lagoon (Maricá‐RJ, Brazil). The cyanobacterial biomass was negatively correlated with nitrate plus nitrite concentrations and DIN/PO 4 , PON/POP, NO 3 /TP, and TN/TP ratios. Synechocystis aquatilis f. salina represented on average 57% of cyanobacterial density during the entire period studied. Based on these data, the species was cultivated under laboratory conditions in ASM‐1 medium and ASM‐1 10 times diluted for all nutrients (ASM‐1/10) with N/P ratios of 3:1, 10:1, and 30:1. Growth rates, chlorophyll‐ a , protein, and carbohydrate intracellular concentrations, carbohydrate release, photosynthetic and respiratory activity, and microcystin production were investigated. It was concluded that the species is well adapted to a condition of nitrogen limitation. High chlorophyll‐ a and protein concentrations as well as the highest photosynthetic rate were observed by cultures grown in ASM‐1 medium with low N/P ratio (3:1). This study aims to evaluate the role of the N/P ratio in controlling the composition of the phytoplanktonic community of the Barra lagoon, according to the physiological response of Synechocystis aquatilis f. salina to different ratios. ©1999 John Wiley & Sons, Inc. Environ Toxicol 14: 37–44, 1999