Effects of NaHSO_3 on the growth and contents of photosynthetic pigments in Dunaliella salina

Bisulfite(NaHSO3) is a substance to accelerate plant cyclic photophosphorylation that can be used safely and envi-ronmentally friendly.In order to optimize the nutrients formula,decrease the production cost and improve the biomass and pigment accumulation of Dunaliella salina,the authors investigated the effects of different concentrations(0.00-0.40mM·L-1) of NaHSO3 on the biomass and photosynthetic pigment contents.The results showed that NaHSO3 could significantly improve the growth,contents of chlorophyll(Chl) a,Chl b,Chl(a+b),carotenoid(Car) and ratio of Chl to Car.The effects firstly in-creased and then decreased with the increase of concentration.Accelerating effects under low concentrations(0.10mM·L-1) were better than those under high concentrations(0.10-0.40mM·L-1),and the maximum accelerating effects were reaches at 0.07mM·L-1.NaHSO3 could increase Chl b content more than Chl a content,which caused the reduction of Chl a content rela-tive to Chl b content;the effects firstly decreased and then increased with the increase of concentration,reducing effects under low concentrations(0.1mM·L-1) were better than those under high concentrations(0.10-0.40mM·L-1),and the minimum reducing effect was achieved at 0.07mM·L-1.The correlations of biomass(Y) to contents of photosynthetic pigments and be-tween contents of photosynthetic pigments were significant or markedly significant,with the highest correlation of Chl b(XChl.b) to biomass(Y=0.284XChl.b-0.883(R2=0.994**)) and the next of Chl to biomass(Y=0.100XChl-2.022(R2=0.993**)),which provided an indirect index to measure the growth of Dunaliella salina in every moment.