The Research On Coccolithophorids Physiological Characteristic Of Bio-Calcification And DMS Production And Species Molecular Marker

Coccolithophorid, a group of marine phytoplanktons, is not only an important component of the ocean and coastal ecosystem but also species which can bring white water bloom extensively. Because of the covering coccoliths whose main element is CaCO₃, coccoliths are very important in global carbon cycle. Then, coccolithophorid is high producer of DMSP (dimethylsulphoniopropionate ) who can be divides into gas DMS. Passing some chemical course, DMS eventually ends up as cloud condensation nuclei (CCN) in the atmosphere. In this way, coccolithophorid productivity helps to increase the reflectiveness (albedo) of the planet by allowing more clouds to form. These show that coccolithophorid bloom can influence marine and atmosphere environment deeply.In the present study, the effect of temperature and salinity on the Emiliania huxleyi and coccolithus neohelis DMS production, the effect of NaHCO₃ and CO₂ on the coccolith calcification of E. huxleyi, and the RAPD molecular marker of E. huxleyi, C. pelagicus, C. neohelis, Cricosphaera elongate, Cricosphaera carterae were studied.The main results were as follow:1. Cultured in different temperature and salinity, the cell growth and the DMS production of E. huxleyi and C. neohelis showed in different trends. The DMS production of E. huxleyi were 0.02, 0.04, 0.12 pg/cell under the temperature of 12,18 and 24℃.The production was higher (0.08 pg/cell) under the salinity of 40 and 30, but lower(0.04 pg/cell) in 35. And the mass DMS production of E. huxleyi appeared from anaphase of exponential phase to decrepit phase.The DMS production of C. neohelis were 0.27, 0.16, 0.15 pg/cell under 12, 18 and 24℃. When salinity was 40 or 30, DMS production was higher (0.19 or 0.18 pg/cell), but only 0.15 pg/cell when cultured in 35. The mass DMS production followed the cell growth. These phenomena were dependent on the complex biochemical process which transfers DMSP into DMS.2. Adding the certain HCO₃-(20 mmol/L ) was priority for calcification. And since the...