暗光缺氧条件下微囊藻的存活及胞内物质释放

The survival of Microcystis under the dark/anoxic condition and its secretion

蓝藻水华爆发期间,沉降至底泥-水界面的蓝藻会面临暗光缺氧胁迫.为研究沉降蓝藻的存活及释放物,模拟暗光缺氧条件,利用不同生长期的微囊藻进行了一系列的实验.结果表明,微囊藻可以在暗光缺氧条件下存活至少6d,释放的溶解性有机碳达到1.86mg C/mg Chl a.不同生长期对微囊藻的存活和释放物产生影响,其中培养55d的微囊藻存活时间最长,培养28d的微囊藻溶解性有机碳的释放量最高.本研究证实暗光缺氧条件下,微囊藻能够存活一段时间并释放有机碳,且存活时间和有机碳释放量与微囊藻生长期相关.

During cyanobacterial blooms,a portion of the biomass would sink to the sediment-water interface and suffer from the dark/anoxic condition.To investigate the survival of Microcystis and its secretion,a series of experiments were conducted with Microcystis in different growth period.The results suggested that Microcystis could survive for at least 6days under the dark/anoxic condition.Meanwhile,Dissolved organic carbon(DOC)secreted by Microcystis reached up to 1.86mg C mg/Chl a.The Microcystis in 55d group could survive longer than other groups,and 28d group had the maximum quantity of secreted DOC.Our study suggested that Microcystis could survive for several days under the dark/anoxic condition,and could secrete DOC during this period.These results were related to the growth period of Microcystis.