Allelopathy of Bacillus amyloliquefaciens to Phaeodactylum tricornutum

The effects of different doses (100 UL, 500 UL, 1000 UL) of Bacillus amyloliquefaciens, metabolites of Bacillus amyloliquefaciens, Bacillus amyloliquefaciens and mixture of metabolites on the growth of Phaeodactylum tricornutum were studied. Count with blood cell counting plate and convert the concentration of long-term culture algal solution. Dilute the algae solution to make its concentration be 20%, 40%, 60%, 80% and 100% of the original respectively. Measure the absorbance value at 663 nm wavelength, and draw the linear standard curve between algae concentration and absorbance. Inhibition rate formula: PI (%) = (1 － n / N0) × 100%。 Among them, N0 and N are the concentration of Phaeodactylum tricornutum in the control group and the concentration of Phaeodactylum tricornutum in the test group respectively; PI is the inhibition ratio. When pi = 50%, the corresponding concentration is EC50.