Effect of Rhodopseudomonas palustris on the storage of Oocystis borgei at normal temperature

Oocystis borgei is dominant algae in subtropical prawn farming, which plays an important role in stabling pool ecological structure and regulating water quality. Study on the effect of O. borgei at normal temperature can promote simple storage and the application of O.borgei into shrimp and prawn culture, so as to promote technology of microalgae ecological management. We studied the effect of Rhodopseudomonas palustris with different concentration on the storage of O.borgei at 25 ℃, 30 ℃ and 35 ℃. The results show that, in each temperature the survival rate and chlorophyll a content of O.borgei are positively correlated with the concentration of R.palustris, as well as its specific growth rate and chlorophyll a content after re-culturing. The best concentration of R.palustris is 1.94106 cellsmL-1, and the optimal temperature for O.borgei storage is 25 ℃, while the specific growth rate of O.borgei after re-culturing at 30 ℃(0.432) is higher than that of at 25 ℃. To sum up, when 1.94106 cellsmL-1 R.palustris added at 25 ℃, we may get the optimal O.borgei storage with the survival rate 87.5% and the chlorophyll a content 31.14 gL-1, and a good storage of O.borgei after re-culturing with the specific growth rate 0.424 and the chlorophyll a 55.94 gL-1.