Effect Of Chitosan Oligosaccharide And Alginate Oligosaccharide On Digestive Ability And Gastrointestinal Microbial Community Of Juvenile Turbot (Scophthalmus Maximus)

This thesis was studied the effect of dietary supplementation of chitosan oligosaccharide and alginate oligosaccharide on apparent nutrient digestibility, digestive enzyme activity, gut morphology and gut microbiota of turbot(Scophthalmus maximus).1. In the experiment, effects of chitosan oligosaccharide on apparent nutrient digestibility, digestive enzyme activity, gut morphology of turbot(Scophthalmus maximus) was studied. The basal diet was formulated to contain 52.79% crude protein, 13.67% crude lipid and 13.67MJ/kg gross energy. A total of five treatments, supplements of 0, 0.02, 0.05, 0.2 and 0.5% chitosan oligosaccharide were singularity added to the basal diet, and named as C0, C1,C2,C3 and C4,respectively. Each diet was fed to three replicate groups of turbot(initial body weight : averaging 17.70±0.10g), and each replicate had 20 fish. The experiment was lasted 70 d. The result showed that: adding chitosan oligosaccharide in feed turbot apparent digestibility results show that with increasing concentrations of chitosan oligosaccharide, the apparent digestibility of nutrients turbot on the rise. The apparent digestibility index showed that dry matter digestibility, crude protein digestibility and crude fat digestibility were showed in C4 group higher than control group(P<0.05). Digestive enzyme activities as follows: there are no significant difference(P>0.05) in gut digestive enzyme indices among the treatments fed with added chitosan oligosaccharide feed, except C2 group, amylase activity of C2 group is significantly higher than control group. Intestinal microvilli of add chitosan oligosaccharide groups were significantly higher than control group(P<0.05), except C1 group. Goblet cell of C4 group was significantly bigger than control group(P<0.05). Mucosal fold of chitosan oligosaccharide inclusion groups were significantly higher than control group(P<0.05).2. In the experiment, effects of alginate oligosaccharide on apparent nutrient digestibility, digestive enzyme activity, gut morphology of turbot(Scophthalmus maximus) was studied. The basal diet was formulated to contain 52.79% crude protein, 13.67% crude lipid and 13.67MJ/kg gross energy. A total of five treatments, supplements of 0, 0.02, 0.05, 0.2 and 0.5% chitosan oligosaccharide were singularity added to the basal diet, and named as A0, A1, A2, A3 and A4,respectively. Each diet was fed to three replicate groups of turbot(initial body weight: averaging 17.70±0.10g), and each replicate had 20 fish. The experiment was lasted 70 d. The result showed that: 1) apparent nutrient digestibility of fish did not show significantly difference among all groups(P>0.05). 2) dietary alginate oligosaccharides within turbot intestinal protease, lipase and amylase activity had no significant effect(P> 0.05); 3) intestinal tissue slices observed intestinal alginic acid oligosaccharide treatment groups microvilli length were higher, but there was no significant difference(P> 0.05), intestinal folds height were higher, but a significant increase compared to the significant difference(P> 0.05), goblet cell size with the control group(P <0.05); add alginic acid oligosaccharide in diet for turbot turbot intestinal structure, has no effect on digestive enzyme activities and apparent digestibility of feed.3. Effect Oligochitosan turbot intestinal structure. Mainly through high-throughput sequencing(MiSeq) Technical Analysis oligochitosan as feed additives turbot intestinal bacterial diversity. Bacterial 16 SrRNA sequence characteristic sequence fragment V4 after MiSeq, found within turbot rich diversity of intestinal bacteria. The results show: alpha diversity analysis results, the test group of Shannon index was significantly lower than the control group(P <0.05) and the experimental group Chao1 index and the ACE index of the control group was significantly reduced(P <0.05), by VNNE FIG. can be observed that the total number of significantly more than the control group OTU Add oligochitosan test group, the analysis accounted for the major categories of bacteria in the intestinal tract, where the control group Proteobacteria higher than the experimental group, the experimental group and C2 and C3 the Bacteroides.4. Effect of alginic acid oligosaccharide turbot intestinal flora diversity. By high-throughput sequencing(MiSeq) Technical Analysis alginic acid oligosaccharide as a feed additive for turbot diversity of gut bacteria. Bacterial 16 SrRNA sequence characteristic sequence fragment V4 after MiSeq, found within turbot rich diversity of intestinal bacteria. The results show: alpha diversity analysis results, the test group of Shannon index were lower than the control group, except for A1 test group, the other test group and the control group had significant difference(P <0.05), the test group Chao1 index and ACE index were lower than the control group, the experimental group except A2, other experimental group and the control group had no significant difference(P> 0.05), can be observed by VNNE diagram, the total number of the control group OUT adding alginic acid oligosaccharide test were similar, and among the five treatment groups the same as the total number OTU 791, high similarity analysis accounted for the major categories of bacteria in the intestinal tract, where the control group Proteobacteria higher than the experimental group.