The Study Of Polyamines’ Influence On The Growth Of HABs Algae And Its Characteristic During The Decomposing Process Of Ulva Prolifera

Based on three experiments, HABs algae culture taking exogenous biogenicamines as orthogonal test factors, succession simulation experiment by culturingProrocentrum donghaiense in Skeletonema costatum filtrate, decomposingexperiment of Ulva prolifera, we studied how the biogenic amines affect HABsalgae’s growth, the function characteristics of polyamines when HABs change fromSkeletonema costatum to Prorocentrum donghaiense in East China Sea, and thecharacteristics of polyamines in seawater during the decomposing process of Ulvaprolifera.The influences varied in degrees and trends when different biogenic amines actedon different HAB algae. Among them,2-phenylethylamine was the most significantimpact factor on the HAB algae’s growth. Spermidine affected Alexandriumtamarense and Thalassiosira sp. the most, while spermine was the biggest influenceon Prorocentrum donghaiense and Skeletonema costatum in three tested polyamines.Polyamines were considered as factors that affected the succession of HABs fromSkeletonema costatum to Prorocentrum donghaiense in East China Sea,2010, amongwhich spermine may be the dominating factor.Using filtrate in Skeletonema costatum’s dissipation phase, we culturedProrocentrum donghaiense and found the functions of polyamines were different withdifferent nitrogen source mediums. Among them, adding exogenous polyamines werepositive for growth when we took nitrate and urea as nitrogen source supplement, andthe higher the concentration was, the more obvious its effect was, while polyaminesacted contrary in complex organic nitrogen mediums.Spermidine concentration was the highest, in seawater during the decomposing process of Ulva prolifera. Decomposing behaviour was most effected by thetemperature. High temperature indicated higher bacteria densities, faster decomposingspeed and higher concentrations of polyamines. Polyamines levels in seawater hadclose relationship with bacteria densities. We can come to the conclusion that it isbacteria’s decomposing and utilization of organic matters determined characteristicsof polyamines in seawater during the decomposing process of Ulva prolifera.