Salinity-induced oxidative stress-mediated change in fatty acids composition of cyanobacterium Synechococcus sp. PCC7942

摘要

The present study was undertaken to examine the salinity stress-induced physiological and biochemical alterations in the cyanobacterium Synechococcus sp. PCC 7942. Cyanobacterial cultures supplemented with different concentrations of NaCl were evaluated for growth, carbohydrate, total lipid, ROS generation, and stress biomarkers to evaluate the ROS-mediated lipid production in Synechococcus 7942. Salt concentration of 500mM induced a five- and threefold increase in the production of carbohydrates and lipids, respectively. The fatty acids composition in terms of total quantity and oleic acid content of the investigated species was also improved as the salinity level increased from 0 to 500mM NaCl. The data showed maximum MUFA production at 10mM NaCl with dominance of palmitoleic acid (88.3%) and oleic acid (0.31%), whereas PUFA was found to be maximally produced at 250mM NaCl with dominance of linoleic acid. Salt stress enhanced the accumulation of carbohydrate and total lipids and antioxidative enzymes, and modulates the fatty acids and hydrocarbon composition of cyanobacterium. Production of fatty acid and hydrocarbon under saline conditions indicates that salinity can be used as a factor to modulate the biochemical pathways of cyanobacteria toward efficient biofuel production.