Effects Of Probiotics On Growth, Immunity, Digestive Enzymes And Intestinal Microbiota In Juvenile Sea Cucumber Apostichopus Japonicus

The present study was performed to investigate the effects of various levels of dietaryMetschnikowia sp. C14, Hanseniaspora opuntiae C21and Bacillus sp. BC26on the growthperformance, non-specific immunity. Therefore, this paper studied the effects of mixedprobiotic on growth, immune, digestion and intestinal flora in sea cucumber Apostichopusjaponicus after continuous feeding for4weeks.Sea cucumber were fed with the control diet (Igroup) and other five different experimental diets including: II, group C14,basic dietscontaining105cells/g C14;III,group BC26,basic diets containing107cells/g BC26;IV,groupC21,basic diets containing105cells/g C21;V,group Y+B, basic diets containing105cells/g C14and107cells/g BC26;VI,group Y+Y, basic diets containing105cells/g C14and105cells/gC21.Samples were collected and measured after feeding for1、2、3、4weeks respectly. And thenall the six groups were changed to feed with badic diet. Samples were collected and measuredat1、3、5、7、10days after28days feeding.After four weeks feeding, results showed that the intestinal flora of sea cucumber wasdominated by the feeding probiotic. Feeding probiotic caould also change the species andquantity of bacteria in sea cucumber intestine. By this way, group Y+B and Y+Y significantlyimproved the phagocytosis and respiratory burst activity in coelomocytes, Lysozyme(LSZ),nitric oxide synthase(NOS) activities, phenoloxidase activity (PO) in coelomic fluid (CF)(P<0.05) and in coelomocytes cells lysate supernatant (CLS)(P<0.05),digestive enzyme activityin intestineof sea cucumbers than the control group and single probiotic feeding group.Stop feeding probiotic experiments showed that the colonization of feeding probiotic in theintestine reduced with the extension of stopping time. The effects on respiratory burst activityand phagocytosis in coelomocytes, lysozyme in CF, NOS in CLS was disappeard when thenumber of C14in group C14lower than4.43×104CFU; when lower than1.09×105CFU/g, theeffects on lysozyme in CLS, lipase activity and amylase in intestine were disappeard; whenlower than.93×105CFU/g, the effect on trypsin activity in intestine was disappeard.The effects on lipase activity in intestine and NOS in CLS was disappeard when thenumber of C21in group C21lower than1.19×104CFU/g; when lower than2.26×105CFU/g, theeffects on NOS in CF, respiratory burst activity in coelomocytes and trypsin activity in intestinewere disappeared. The effects onlysozyme in CF, respiratory burst activity in coelomocytestrypsin activity in intestine were disappeared when the number of BC26in group BC26lowerthan0.75×107CFU/g; when lower than3.36×107CFU/g, the effects on phenoloxidase activity and NOS in CF, lysozyme in CLSamylase in intestine were disappeard. The trendency ofsignificantly higher than control group in mixed probiotic group Y+B and Y+Y wereprolonged than the single probiotic feeding group. And at the early period of stopping feedingcontaining probiotic diets, the indicators in mixed group showed significantly higher than thesingle probiotic feeding group. So mixed feeding probiotics Y+B and Y+Y have a positiveeffect on growth, immune, digestion and intestinal flora in sea cucumber Apostichopusjaponicus. And after four weeks of continuous feeding, changing to feedbasic diet for5-7dayscan still get the desired effect.