研究了卵圆卡盾藻香港株(Chattonella ovata,Hong Kong strain,COHK)在不同生长期、盐度和营养盐条件下的生长及过氧化氢(H2O2)的产生特点.结果表明,过氧化氢浓度峰值出现在COHK对数生长期(4~8 d),以第6 d达到最大,为2.91×10-4nmol.cell-1.在N∶P为16∶1、32∶1和64∶1的情况下,COHK生长较快,以32∶1时生长速率最快(0.58 div.d-1).COHK产生H2O2的量与藻类生长呈相反趋势,在N∶P为4∶1和8∶1的情况下,藻细胞生长率较低,但单位藻细胞H2O2浓度较高.单位藻细胞H2O2浓度在N∶P为4∶1时最大,达到1.26×10-4nmol.cell-1.COHK在盐度为20和25时生长率较高,在盐度为10、15和30时生长率较低,表明低盐和高盐条件均不利于COHK的生长.低盐度和高盐度均有利于COHK过氧化氢的产生,在盐度为10时,单位藻细胞的H2O2量最高,达到2.2×10-4nmol.cell-1;但盐度在15~25范围内,单位藻细胞H2O2量相差不大(0.7×10-4~0.9×10-4nmol.cell-1).Fe3+可显著影响COHK的生长,Fe3+浓度范围为0.2×10-8~1×10-8mol.L-1时,COHK生长率较高.缺铁条件下(Fe3+浓度为0),COHK生长率最低(0.1 div.d-1),而Fe3+浓度较高时(5×10-8mol.L-1),藻细胞生长率也有所降低.缺铁以及高铁条件下,卵圆卡盾藻的H2O2产量增加,H2O2浓度分别为0.97×10-4和0.95×10-4nmol.cell-1.
The growth characteristics of Chattonella ovata Hong Kong strain(COHK) under different salinity and nutrient conditions and production of peroxide hydrogen(H2O2) in different growth phase were investigated in laboratory unialgal culture experiment.The results showed that high concentration of H2O2 was reached during the logarithmic phase from 4th to 8th days,corresponding to the maximum value of 2.91×10-4 nmol·cell-1 on the 6th day.When the N∶P ratios were 16∶1,32∶1 and 64∶1,COHK possessed the relatively high growth rate and cell concentration,however,growth rate of COHK was lower with the N∶P ratios of 4∶1 and 8∶1.The H2O2 concentration reached the highest(1.26×10-4 nmol·cell-1) with the N∶P ratio of 4∶1,which suggested that production of H2O2 was reversely related to the growth of COHK.The optimum salinities for COHK were 20 and 25.When the salinities were 10,15 and 30,the growth rate of COHK was lower,showing lower and higher salinities inhibited the growth of COHK.Salinity also influenced the production of H2O2.The highest concentration of H2O2 among the experiments,2.2×10-4 nmol·cell-1,was observed at the salinity of 10,while there was no significant difference of H2O2 concentration from the salinity range of 15 to 30.The optimal Fe3+ concentration for the growth of COHK was from 0.2×10-8to 1×10-8mol·L-1,where growth rate were relatively higher.Growth rate of COHK was depressed in absence(0 mol·L-1) and high concentration of Fe3+(5×10-8 mol·L-1),with which H2O2 concentration was 0.97×10-4 and 0.95×10-4 nmol·cell-1,respectively.