摘要
Phaeocystis globosa is a harmful algal bloom(HAB)species worldwide.Using modified clay(MC)to control HABs and to mitigate their adverse effects is currently a commonly used method in China.In this paper,the effects of oxidized composite modified clay(OXI-MC)on P.globosa were studied from different perspectives.The results show that the OXI-MC could effectively remove P.globosa and inhibit both the growth of residual algal cells and the formation of new colonies.The P.globosa algal biomass removal efficiencies after 3 h reached 90%at a dose of 0.1 g/L,and the number of colonies with different particle sizes was greatly reduced.Compared with those of the control,the superoxide dismutase(SOD)activity,catalase(CAT)activity,and malondialdehyde(MDA)content of the residual algae significantly increased,indicating that OXI-MC caused oxidative stress in the algal cells.In addition,we evaluated the effects of OXI-MC on the photosynthesis of residual microalgae and found that the maximal photochemical efficiency of photosystem II(PSII)under dark adaptation(F v/F m)and actual photochemical efficiency of PSII(ФPSII)decreased,severely damaging the photosynthesis efficiency,implying that OXI-MC effected the photosynthesis system of P.globosa.The results of this study clarify that OXI-MC could remove the most of algal cells and break up the colonies of P.globosa by collision,flocculation,and releasing active substances,as well as inhibit effectively the growth and colony formation of residual P.globosa by causing oxidative stress,reducing photosynthesis activity,accelerating the degradation of polysaccharides,and inhibiting the formation of colonies.
基金
the National Natural Science Foundation of China(No.41576119)
the Taishan Scholars Climbing Program of Shandong Province of 2019
the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0504-2)
the National Key Research and Development Program of China(No.2017YFC1404300)。
