Effects of Chattonella marina cell-free filtrate on bloom microalgae and co-culture of it and microalgae

The growth effect of Chattonella marina cell-free filtrate on four species of microalgae and the co-culture effect of C.marina and Prorocentrum donghaiense or Alexandrium tamarense were studied under the laboratory conditions.The results showed that cell-free filtrate of C.marina could significantly inhibit the growth rate of Phaeodactylum tricornutum,P.donghaiense and A.tamarense(P0.01),while the growth rate of Skeletonema costatum was not significantly different versus the control group when treated with low concentrations of cell-free filtrate.Only when the concentration of cell-free filtrate was up to(15 mL,20 mL) / 40mL,was the growth of S.costatum significantly inhibited(P0.01).The co-culture of C.marina and two kinds of dinoflagellate P.donghaiense or A.tamarense significantly contributed to the growth of C.marina and inhibited the growth of dinoflagellate.The results of co-culture experiments showed that allelopathy or competitive effect of nutrients might exist between C.marina and dinoflagellate.Meanwhile,the cell-free filtrate experiments showed that C.marina could produce allelochemicals to inhibit the growth of microalgae.