Composite culture medium for algae-killing bacterium and preparation method thereof

The invention discloses a composite culture medium for an algae-killing bacterium and a preparation method thereof, relates to a culture medium, and provides a composite culture medium suitable for culturing the algae-killing bacterium Alteromonas addita DH46 and capable of obviously improving the cell density of the algae-killing bacterium, and a preparation method thereof. The composite culture medium comprises the following components, namely 1L of aged seawater contains 1 to 15g of tryptone, 0.5 to 5g of yeast powder, 0.5 to 5g of soluble starch, 0.1 to 3g of NaNO3, and 0.1 to 3g of MgSO4, wherein the pH is 7.2 to 7.8, and the salinity of the aged seawater is 2 to 4 percent. The preparation method comprises the following steps of: adding the tryptone, the yeast powder, the soluble starch, the NaNO3, and the MgSO4 into the aged seawater for fixing the volume, regulating the pH to be 7.2-7.8, and sterilizing to obtain the composite culture medium for the algae-killing bacterium.