Beneficial effects of Metschnikowia sp. C14 on growth and intestinal digestive enzymes of juvenile sea cucumber Apostichopus japonicus

We investigated the effects of dietary administration Metschnikowia sp. C14 on growth and intestinal digestive enzymes of juvenile sea cucumber Apostichopus japonicus. Sea cucumbers were fed with diets containing C14 at 0 (control), 104, 105 and 106 CFU/g feed, respectively. After feeding for 45 days, the specific growth rate was higher in sea cucumbers fed C14-supplemented diets at 104 and 105 CFU/g feed than in the controls (P<0.05). The intestinal trypsin and lipase activities in sea cucumbers were significantly enhanced by C14 administration at 104, 105 and 106 CFU/g feed compared to those of the controls (P<0.05). After feeding for 23-42 days, the presence of C14 was evidenced in the intestinal community of sea cucumbers by denaturing gradient gel electrophoresis (DGGE). The intestinal fungal communities of sea cucumbers fed C14-supplemented diets were different from that of the control on day 42. Additionally, sea cucumbers were switched to the control diet from day 16 to day 46. As confirmed by DGGE, C11 colonization of the intestine could be detected until day 46. The present study demonstrates that C14 is able to successfully colonize the intestine through dietary supplementation, and that this colonization improves the growth and intestinal digestive enzymes of juvenile A. japonicus.