Ecophysiological characteristics of red, green, and brown strains of the Baltic picocyanobacterium Synechococcus sp. – a laboratory study

摘要: Abstract. The contribution of picocyanobacteria (PCY) to summer phytoplankton blooms, accompanied by an ecological crisis is a new phenomenon in Europe. This issue requires careful investigation. present study examined the response of Synechococcus sp. physiology different environmental conditions. Three strains Synechococcus (red BA-120, green BA-124, and brown BA-132) were cultivated laboratory under previously determined environmental conditions. These conditions as follows: temperature ( T ) from 10 5 25  ∘ C, salinity from 3 18 PSU, and photosynthetically active radiation (PAR) 90 to 280  µ mol photons m −2  s −1 , which gave 64 combinations of synthetic, though realistic, scenarios. Scenarios reflecting all possible combinations applied experiments. Results pointed differences final numbers cells among strains. However, there was also similar tendency for BA-124 and BA-132, demonstrated the highest concentrations PCY at elevated PAR. was also case BA-120 but only certain degree number cells started decrease above 190   PAR. Pigmentation, chlorophyll  (Chl  ), fluorescence, rate photosynthesis presented both similarities In this context, more consistent features observed between brown red when compared to green. paper, ecophysiological responses are defined.