南极夏季沿海P.Pouchetii繁殖期间丙烯酸和二甲基硫的自然产率

样品取自东南极距戴维斯站 1 0公里沿海海域 1 5米水层。从 1 988年 1 1月至 1 989年 2月 ,利用高压液相色谱和气相色谱等手段对海藻 Phaeocystis Pouchetii整个繁殖过程中所产生的有毒物质丙烯酸和二甲基硫的浓度进行了长期连续测定。结果表明 ,丙烯酸和二甲基硫的含量变化范围分别为 0 .0 0 1～ 0 .5 1 0 μmol/L和 0 .0 0 3～ 0 .5 88μmol/L。二者的含量变化与 P.Pouchetii细胞数量的变化完全一致 (相关系数均为 0 .998)。由此可见丙烯酸和二甲基硫产生于 P.Pouchetii是无疑的。丙烯酸和二甲基硫的最高产率分别是 9.75 8× 1 0 - 8μmol/cell和 1 3 .0 90× 1 0 - 8μmol/cell。其主要产生途径是 :P.Pouchetii摄取氨基酸 (如蛋氨酸 )后 ,经甲基化、脱胺等作用 ,在细胞分裂和代谢过程中产生二甲基硫丙酸 (DMSP) ,进而以一对一的方式分解成丙烯酸和二甲基硫。

PRIMARY PRODUCTIVITY OF ACRYLIC ACID AND DIMETHYL SULFIDE DURING A SUMMER BLOOM OF PHAEOCYSTIS POUCHETII IN ANTARCTIC COASTAL WATER

Samples were collected,over P.Pouchetii bloom period beginning in Novermber 1988,from 15m water column 10km off shore from Davis Station,Vestfold Hill,Antarctica.The concentration of toxin compounds,acrylic acid and dimethylsulfide(DMS) in water were determined by HPLC and GC.The results showed that the concentrations change of acrylic acid was 0.001～0.510μmol/L and DMS was 0.003～0.588μmol/L during P.Pouchetii bloom.The concentrations of both were increased from later December and the highest peak of concentrations appeared in early January 1989,then gradually decreased to lower level from mid January to February.This variation in concentrations of acrylic acid and DMS corresponded with the observed variation in cells number of the unicelluar algae P.Pouchetii.The correlation coefficient of relative(R) for acrylic acid against P.Pouchetii and DMS against P.Pouchetii were all 0.998.It is undoubted that P.Pouchetii produced acrylic acid and DMS.The major acrylic acid and DMS pathway of P.Pouchetii showed that dimethylsulfonlum propionate (DMSP) is produced from amino acids(such as methinoine) by successive s methylation,de amination and decarboxylation.DMSP is cleavaged to produce acrylic acid and DMS on one to one basis.The highest primary productivity of acrylic acid and DMS were 9.76×10 -8 μmol/cell and 13.09×10 -8 μmol/cell during a summer bloom of P.Pouchetii in Antarctic coastal water.