Influence of salinity on growth and biochemical composition of green algae Botryococcus

The effect of 0.3 and 0.7 M NaCl on biomass yield, total nitrogen content, intracellular lipid content, hydrocarbons and fatty acid profile of the lipids of the alga Botryococcus braunii Kutz IPPAS H-252 in different phases of the culture cycle was studied. The presence of sodium chloride in the medium inhibited the growth of algal cells for the first three days of the experiment, causing a decrease in total nitrogen, enhanced synthesis of triacylglycerols, and considerable changes in the lipid fatty acid profile: decreases in polyenoic acid contents (from 68.34% to 29.38% and 12.8%) and proportions of long-chain saturated acids (from 0.53% to 5.3% and 14.13% of the total fatty acids) at 0.3 M NaCl and 0.7 M NaCl, respectively. In later phases of the culture, at 0.3 M NaCl, the content of polyenoic acids rose to the values characteristic of the active growth phase of this alga. At 0.7 M NaCl, the proportion of polyenoic acids grew less significantly, but biomass concentration and total nitrogen increased, similarly to the experiment with 0.3 M NaCl, which can also be indicative of adaptation of the alga to 0.7 M NaCl.