HU Fanguang, GUO Pingping, MA Danping,WU Zhihong, SUN Fuxin, WANG Zhigang

Abstract: To study the impact of different doses of Bacillus subtilis in promoting Scophthalmus maximus（Linnaeus）growth and aquaculture water environment,the experiment explored the feasibility of its application by using feed additives (viable cells number 2.0×10⁹ CFU/g )made from homologous Bacillus Subtilis which were isolated from Scophthalmus maximus（Linnaeus）intestinal, 0‰, 5‰, 10‰ and 15‰ dosages in promoting Scophthalmus maximus（Linnaeus）growth were studied. The experiment showed: compared with the control group, after fed 20days, 40day and 60day with 5‰ additives, feed coefficient reduced by 10.3%, 5.9%,-5.8% respectively, protein efficiency ratio increased by 12.1%, 4.4%, -4.4% respectively, weight gain rate increased by 4.4 %, -14.6%, -10.7% respectively; as to the groups which were fed with 10‰ and 15‰ additives, feed coefficient was higher than the control group, protein efficiency ration and weight gain rate was lower than the control group（P<0.05）；compared with the control group,  at the 60^th day, NH₄⁺-N、NO₂⁺-N、NO₃^—N concentration was reduced by 43.5%、62.5%、40.8% in 5‰ group, 42.5%, 68.5%, 46.4% in 10‰ group, 45.9%, 66.1%, 51.1%（P<0.05）in 15‰ group. The result shows: Scophthalmus maximus（Linnaeus）grows better with 5‰Bacillus Subtilis, NH₄⁺-N, NO₂^—-N, NO₃^—-N concentration can be reduced remarkably if 5‰, 10‰, 15‰ additives are added in aquaculture water volume.

Key words: Bacillus Subtilis, feed coefficient, protein efficiency ratio, Scophthalmus maximus, aquaculture