Abstract: In order to explore the antibacterial effect of Chinese herbal medicine on pathogenic bacteria in aquaculture and its influence on microbial population, the Chinese herbs after the initial screening were proportioned, and the orthogonal test was used to study the effect of the combination of Chinese herbal medicine on pathogenic bacteria. The results showed that 12 selected Chinese herbal medicines all had bacteriostatic effects to varying degrees. Among them, dark plum, Chuanlian, pomegranate peel and Pulsatilla chinensis had obvious inhibitory effects on five pathogenic bacteria. The average bacteriostatic circle of the combination of “dark plum+Pulsatilla chinensis” reached 13.23 mm, the MIC value decreased significantly, and it had high drug sensitivity. In addition, the addition of Chinese herbal medicine had changed the abundance and diversity of bacteria in the water. Compared with the control, the experimental group “Mu+Gr”, “Mu+Co” and “Mu+Pu” had decreased the bacterial abundance by 28.16%, 25.33% and 13.27%, respectively. The combination of Chinese herbal medicine could effectively provide new ideas for the prevention and control of pathogens in agriculture and fishery, thereby reducing the abuse of chemicals.

Key words: Chinese herbal medicine, aquaculture, microbial population, pathogenic bacteria