Effects Of Fermented Soybean Meal Replacing Fish Meal And Soybean Meal On Growth And Physiology Of Japanese Eel Black Fry(Anguilla Anguilla)

1.Effect of fermented soybean meal replacing fish meal and soybean meal on growth,serum and liver antioxidant capacity and biochemical indexes of Japanese eel black fry.This study intended to explore the effectiveness of fermented soybean meal(FSBM)replacing fish meal(FM)and possible effects of soybean meal(SBM)in the feed of Japanese eel black fry.Five trial diets were prepared in this study,the diet containing 60% fish meal and 5% soybean meal inclusion(A)was treated as the control group,and those 11.7% and 23.3% of FM in A replaced by 10%(B)and 20%(C)FSBM were treated as trial diets.On this basis,4.5% of FSBM were used to replace the 100% of SBM in B and C respectively,which were treated as other two trial diets D and E.Fish with initial average body weight of(0.405 ± 0.003)g were cultured with above diets for 76 days.Results showed that with the increase of FSBM,the specific growth rate,weight gain rate and survival rate increased gradually.The specific growth rate,weight gain rate and survival rate of group B were significantly higher than that of group D while group C were not significantly higher than that of group E.In serum,activity of alanine aminotransferase(ALT),aspartate aminotransferase(AST)and malondialdehyde(MDA)content of the trial groups were lower than that of the control group,total antioxidant capacity(T-AOC)was significantly higher than that of control group except group D;The MDA content of group B was significantly lower than that of group D.With the increase of FSBM,T-AOC,total superoxide disumutase(T-SOD)and catalase(CAT)activity in the liver increased gradually,MDA content was opposite,activities of ALT and AST had an increasing trend followed by a decreasing trend.There were increased contents of total protein(TP),albumin(ALB)and globulin(GLB)in serum when increasing dietary amount of FSBM,and higher value of serum TP and GLB in 5% SBM inclusion group compared to that without SBM when with amount of FM.The above results indicated that FSBM replacing FM in diets could improve the growth performance,antioxidant ability and liver function of Japanese eel black fry.The effect of SBM on the growth performance of Japanese eel black fry is different in varying amount of FSBM.It is beneficial to its growth on the low level of FSBM,but no such phenomenon on the high level of FSBM.2.Effect of fermented soybean meal replacing fish meal and soybean meal on muscle composition,amino acids and fatty acids of Japanese eel black fry.In order to study the effects of fermented soybean meal replacing fish meal and soybean meal on muscle composition,amino acids and fatty acids of Japanese eel black fry.Based on the experiment in chapter one of this thesis,take the muscle of Japanese eel black fry of five groups as samples to measure indicators.Results shows that: A total of 17 kinds of amino acids were measured,including 7 kinds of essential amino acids(EAA),8 kinds of nonessential amino acids(NEAA),2 kinds of half-essential amino acids(HEAA).A total of 23 kinds of fatty acids(FA)were measured,including 6 kinds of saturated fatty acids(SFA),8 kinds of monounsaturated fatty acids(MUFA),9 kinds of polyunsaturated fatty acids(PUFA).Among group of A&B&C,with the increase of FSBM,the protein of muscle decreased first and then increased,and the fat was opposite;ΣEAA,ΣNEAA and ΣEAA/ΣNEAA was increased;ΣHEAA,ΣFAA was no significant change;The content of 14 kinds of fatty acids showed a trend of decreasing after increased,the same as ΣSFA,ΣMUFA,ΣPUFA and ∑n-3PUFA.Between group B&D,since the lack of SBM,the protein of muscle was increased,the fat was opposite;14 kinds of amino acids was increased,3 kinds of amino acids was no significant change;19 kinds of fatty acids and the 6 indexes of ΣPUFA,ΣMUFA,∑n-3PUFA,∑n-6PUFA,ΣSFA and ΣFA was decreased.Between group C&E,since the lack of SBM,the protein of muscle was decreased,the fat was opposite;The content of Met in group E was increased than group C;14 kinds of amino acids was decreased,3 kinds of amino acids was no significant change;4 kinds of fatty acids was increased,2 kinds of fatty acids was decreased.The above results indicated that the content of crude protein,crude fat,amino acid and fatty acid in muscle of Japanese eel black fry could be affected by FSBM which was beneficial to the composition of amino acid and fatty acid.The effects of SBM were different on the crude protein,crude fat,amino acid and fatty acid in muscle of Japanese eel black fry under the different content of FBSM.SBM was beneficial to increase the content of the fatty acid in muscle on the low content of dietary FBSM,while on the high content of dietary FBSM,SBM was beneficial toenhance the content of the amino acid in muscle.3.Effect of fermented soybean meal replacing fish meal and soybean meal on the intestinal flora in Japanese eel black fry.In order to further study the effect of FBSM replacing fish meal and soybean meal on the intestinal flora in Japanese eel black fry,based on the growth result(Chapter 1),the intestines of Japanese eel black fry in 5 groups were collected under sterile condition,which were used for high-throughput sequencing.The results indicated that 10% FSBM can promote the Alpha diversity and Community richness of intestinal flora in Japanese eel black fry.SBM could promote the Alpha diversity of intestinal flora in Japanese eel black fry on the low content of FSBM,but was no effect on the high content of FSBM.The diet containing FSBM and SBM could reduce the abundance of pathogenic bacteria,and did not reduce the the metabolism of amino acids,lipids and carbohydrates of intestinal flora in Japanese eel black fry.4.Effect of fermented soybean meal replacing fish meal and soybean meal on the liver metabolism of Japanese eel black fry.Metabonomics is a system biology research method closely related to phenotype and specialized in the study of the effects of the changing external environment on the metabolites of organisms.Thus the link between growth performance(Chapter 1)and the liver metabolism of Japanese eel black fry when FSBM replacing fish meal and SBM was investigated based on the metabonomics analysis of livers in 5 groups.Results showed that among group of A&B&C,with the increase of FSBM,31 kinds of differential metabolites were detected(P<0.05);The content of cis-aconitate was upregulated;The content of succinate,citrate and malate were downregulated;KEGG pathway resulted shows that FSBM could significantly affect the glyoxylate and dicarboxylate metabolism and citrate cycle in the liver(P<0.05).Between group B&D,since the lack of SBM,29 kinds of differential metabolites were detected(P<0.05);The content of putrescine and N-acetylputrescine were upregulated,which were harmful to fish;KEGG pathway results showed that the SBM could significantly affect arginine and proline metabolism,glutathione metabolism and purine metabolism in the liver(P<0.05).Between group C&E,since the lack of SBM,67 kinds of differential metabolites were detected(P<0.05);The content of protocatechuate,quinate,L-Noradrenaline,fumarate,glycolate were downregulated;KEGG pathway resulted shows that SBM could significantly affect 7 kinds of metabolic pathways such as glyoxylate and dicarboxylate metabolism,citrate cycle and arginine and proline metabolism in the liver of Japanese eel black fry(P<0.05).The above results indicated tha FSBM might improve the metabolism level of in the liver of Japanese eel black fry through the two metabolic pathways of glyoxylate and dicarboxylate metabolism and citrate cycle,so that promote fish growth.On the low content of FSBM,the diet with SBM could improve the glycine metabolism in the liver of Japanese eel black fry,and consequently promote fish growth.On the high content of FSBM,the diet with SBM did not significantly change the growth of Japanese eel black fry,but it significantly affected the contents of various metabolites and pathways.5.The potential transcription molecular mechanism of liver metabolism when fermented soybean meal replacing fish meal and soybean meal in the diet of Japanese eel black fry.The transcription of DNA usually changes with the growth condition,feed and other various factors.Therefore,it is very meaningful to study the metabolism in the liver of Japanese eel black fry by transcriptomics.Here,liver transcriptomics analysis was conducted by an integrated method with liver metabonomics(Chapter 4),to understand the transcription molecular mechanism of liver metabolism.Results showed that among groups of A&B&C,with the increase of FSBM,the expression of gene MSTRG.1873.3 that regulating the metabolism of enzyme MDH1 was upregulated,which was involved in metabolic pathways including citrate cycle and glyoxylate and dicarboxylate metabolism(P<0.05);Thus,it caused the decreased content of malate(P<0.05).Between groups B&D,since the lack of SBM,the expression of gene MSTRG.14624.4 regulating enzyme ADA was downregulated,the expression of gene MSTRG.9984.5 regulating enzyme spe E was upregulated,the expression of gene MSTRG.8362.2 that regulating enzyme spe B was upregulated.Because those genes were involved in metabolic pathways such as purine metabolism and glutathione metabolism,the content of putrescine showed upregulated.Between groups C&E,since the lack of SBM,the expression of gene MSTRG.17176.1,gene MSTRG.28724.1 and gene MSTRG.26450.4 that respectively regulating pck A,OGDH and roc D showed significant changes(P<0.05).The above results indicated that FSBM significantly changed transcription of the genes which involved citrate cycle and glyoxylate and dicarboxylate metabolism,and thus altered the content of key metabolites,improved liver metabolic efficiency and growth of Japanese eel black fry.On the low content of FSBM,the lack of SBM did cause changes in transcription of the genes which involved purine metabolism and glutathione metabolism,and thus changed the content of key metabolites,furthermore reduced metabolic efficiency and growth of Japanese eel black fry.On the high content of FSBM,whether the diet contained SBM or not,it did not significantly changed the growth of Japanese eel black fry,although various m RNA and enzymes were changed.