Metabonomics analysis of nitrogen deficiency-generated strains of <italic>Synechocystis</italic> sp.

Abstract

<italic>Synechocystis</italic> sp. PCC6803 is a non nitrogen-fixing cyanobacteria, which is an important model organism and can be used as a research material for experimental evolution. Experimental evolution refers to the process of changing biological and genetic traits of organisms to adapt to the artificial environment. To explore the adaptation mechanism of organisms under stress environment, a 615 d experimental evolution with nitrogen deficiency as the selective pressure was conducted on wild type <italic>Synechocystis</italic> sp. PCC6803 in this study. Finally, 8 nitrogen deficiency-generated strains were obtained, and the growth of nitrogen deficiency-generated strain was tested. The results showed that the specific growth rates of nitrogen deficiency-generated strains were not significantly different from that of the control strain under nitrogen deficient conditions. The metabolites of these strains were detected by gas chromatography-mass spectrometry. A total of 52 metabolites, including amino acids, fatty acids, sugars and their derivatives, were detected. Based on the composition of metabolites, these strains were analyzed by hierarchical cluster analysis. Three clusters were formed within these strains. The nitrogen deficiency-generated strains with high specific growth rate, the strains with low specific growth rate and the control strain formed different clusters. These results suggest that the nitrogen deficiency-generated strains obtained from the same way are different in composition of metabolites and may use different metabolic mechanisms to deal with the nitrogen deficiency stress.