Effect of Rising Temperature and Carbon Dioxide on the Growth, Photophysiology, and Elemental Ratios of Marine Synechococcus: A Multistressor Approach

Marine picocyanobacteria belonging to the genus Synechococcus are one of most abundant photosynthetic organisms on Earth. They often exposed large fluctuations in temperature and CO2 concentrations ocean, which expected further change coming decades due ocean acidification warming resulting from rising atmospheric levels. To decipher effect changing levels Synechococcus, six strains previously isolated various coastal open sites were a matrix three different temperatures (22 °C, 24 °C 26 °C) (400 ppm, 600 ppm 800 ppm). Thereafter, specific growth rates, photophysiological parameters (σPSII Fv/Fm), C/N (mol/mol) ratios nitrogen stable isotopic composition (δ15N (‰)) measured. Temperature was found be stronger driver changes rates photophysiology strains. Carbon-concentrating mechanisms (CCM) operational these that shield machinery directly sensing ambient possibly played major role causing minimal under varying