Effect of different combinations of probiotics on digestibility and immunity index in sea cucumber Apostichopus japonicus

The lactic acid bacteria L-2,Bacillus K-3 and Bacillus J-9 isolated from intestines of sea cucumber Apostichopus japonicus were added to the diets at three rates of 0,103,and 105 cfu/mL and fed to the sea cucumber by orthogonal design for 30 days.The activities of protease,amylase,cellulolytic enzymes,superoxide dismutase and lysozyme were determined in the intestines.The results showed that supplementation of the probiotics improved digestive enzyme activities,especially the protease and amylase in the sea cucumber,and immunity.The protease activity was as high five times in Group 6 as in the control.There was 100% higher amylase activity in Group 6 than that in the control.There were no significant differences in the cellulolytic enzyme activity in all treatments.The maximal superoxide dismutase and lysozyme activities were observed in the group 6(lactic acid bacteria L-2 103 cfu/mL;bacillus K-3 105 cfu/mL;bacillus J-9 0 cfu/mL).