Several reports have revealed the vital role that probiotics play in fish growth and health.However,few works are available for host gut-derived probiotics on the growth,immunity,and gut microbiota of fish,especially ...Several reports have revealed the vital role that probiotics play in fish growth and health.However,few works are available for host gut-derived probiotics on the growth,immunity,and gut microbiota of fish,especially in hybrid grouper (♀Epinephelus fuscoguttatus×♂Epinephelus lanceolatus) due to their isolation difficulty and functional verification.This study aimed at assessing 3 host gut-derived Bacillus species?effects on the growth,immune and antioxidant-biochemical responses,haematological parameters,intestinal morphology,immune-related gene expression,gut microbiota,and disease resistance against Vibrio harveyi in hybrid grouper.A total of 480 hybrid grouper (initial weight=9.03±0.02 g) were randomly allotted into 4 groups,namely,the group fed a basal diet without probiotic inclusion (control,B0),the group fed the basal diet with Bacillus velezensis GPSAK4 (BV),the group fed the basal diet with Bacillus subtilis GPSAK9 (BS),and the group fed the basal diet with Bacillus tequilensis GPSAK2 (BT) strains at 1.0×10^(9)CFU/g.After a 6-week feeding trial,the results revealed significant improvements (P<0.05) in the growth performance,whole fish-body proximate composition,blood haematological parameters,serum,liver,and intestinal biochemical indexes,intestinal morphology,and protection against V.harveyi pathogen in the probiotic-treated groups compared with the untreated.Additionally,the expressions of intestinal tight junction genes (occludin and ZO1),pro-and anti-inflammatory genes,including IL1β,IL6,IL8,TNFa,MyD88,IL10,and TGFβ,were upregulated (P<0.05) after Bacillus species administration.Host gut-derived Bacillus supplementation shaped the gut microbiota by significantly increasing (P<0.05) the relative abundance of Proteobacteria,Bacteroidetes,Actinobacteria (except the BS group),Acidobacteria(except the BT group),Cyanobacteria (except the BV and BT groups),and Verrucomicrobia phyla,as well as known beneficial genera (Romboutsia,Turicibacter,Epulopiscium,Clostridium_sensu_stricto 1 and 13,Lactobacillus,and Bacillus),but significantly decreased (P<0.05) the abundance of Firmicutes,Chloroflexi,and Fusobacteria phyla,and purported pathogenic genera (Staphylococcus and Photobacterium) compared with the control group.Collectively,the results suggest that B.velezensis GPSAK4,B.subtilis GPSAK9(especially this strain),B.tequilensis GPSAK2 dietary supplementation at 1.0×10^(9)CFU/g has positive effects on the intestinal health of hybrid grouper via microbial composition modulation,thus enhancing the assimilation and absorption of nutrients to boost fish growth,immunity,and disease resistance.展开更多
在盐度5、10、15、20、25、30条件下,以全人工配合饵料饲喂龙虎斑[鞍带石斑鱼（Epinephelus lanceolatus♂）×棕点石斑鱼（E.fuscoguttatus♀）]60 d,研究不同盐度对龙虎斑生长和摄食的影响。结果表明,不同盐度对龙虎斑生长的影响...在盐度5、10、15、20、25、30条件下,以全人工配合饵料饲喂龙虎斑[鞍带石斑鱼（Epinephelus lanceolatus♂）×棕点石斑鱼（E.fuscoguttatus♀）]60 d,研究不同盐度对龙虎斑生长和摄食的影响。结果表明,不同盐度对龙虎斑生长的影响有统计学意义（P〈0.05）,盐度5-20组增长率、特定生长率均高于盐度25、30组,差异有统计学意义（P〈0.05）,盐度10组的增长率最高,为55.08%,盐度15组的特定生长率最大,为2.30%/d,盐度和龙虎斑生长速率的回归方程为K=0.000 09 S 4-0.006 S 3＋0.131 S 2-1.055 S＋4.832（R 2=0.984）;不同盐度对龙虎斑的摄食率和饵料系数影响有统计学意义（P〈0.05）,盐度15组的摄食率最高,为1.64%/d,其次为盐度10组,为1.60%/d,饵料系数在盐度15组最低,为0.820,其次为盐度10组,为0.827。因此,龙虎斑在低盐度条件下生长比高盐度快,摄食率高,饵料利用率高,最佳生长盐度为10-15。展开更多
基金supported financially by the General Program of Natural Science Foundation of Guangdong Province(2021A1515011165)the Department of Education of Guangdong Province (2021ZDZX4005)+2 种基金the National Natural Science Foundation of China (31972808)the Research and Demonstration of Precision Functional Compound Feed Technology of Major Cultured Fishes and Shrimps in South China (2021B0202050002)the China Agriculture Research System of MOF and MARA (CARS-47)。
文摘Several reports have revealed the vital role that probiotics play in fish growth and health.However,few works are available for host gut-derived probiotics on the growth,immunity,and gut microbiota of fish,especially in hybrid grouper (♀Epinephelus fuscoguttatus×♂Epinephelus lanceolatus) due to their isolation difficulty and functional verification.This study aimed at assessing 3 host gut-derived Bacillus species?effects on the growth,immune and antioxidant-biochemical responses,haematological parameters,intestinal morphology,immune-related gene expression,gut microbiota,and disease resistance against Vibrio harveyi in hybrid grouper.A total of 480 hybrid grouper (initial weight=9.03±0.02 g) were randomly allotted into 4 groups,namely,the group fed a basal diet without probiotic inclusion (control,B0),the group fed the basal diet with Bacillus velezensis GPSAK4 (BV),the group fed the basal diet with Bacillus subtilis GPSAK9 (BS),and the group fed the basal diet with Bacillus tequilensis GPSAK2 (BT) strains at 1.0×10^(9)CFU/g.After a 6-week feeding trial,the results revealed significant improvements (P<0.05) in the growth performance,whole fish-body proximate composition,blood haematological parameters,serum,liver,and intestinal biochemical indexes,intestinal morphology,and protection against V.harveyi pathogen in the probiotic-treated groups compared with the untreated.Additionally,the expressions of intestinal tight junction genes (occludin and ZO1),pro-and anti-inflammatory genes,including IL1β,IL6,IL8,TNFa,MyD88,IL10,and TGFβ,were upregulated (P<0.05) after Bacillus species administration.Host gut-derived Bacillus supplementation shaped the gut microbiota by significantly increasing (P<0.05) the relative abundance of Proteobacteria,Bacteroidetes,Actinobacteria (except the BS group),Acidobacteria(except the BT group),Cyanobacteria (except the BV and BT groups),and Verrucomicrobia phyla,as well as known beneficial genera (Romboutsia,Turicibacter,Epulopiscium,Clostridium_sensu_stricto 1 and 13,Lactobacillus,and Bacillus),but significantly decreased (P<0.05) the abundance of Firmicutes,Chloroflexi,and Fusobacteria phyla,and purported pathogenic genera (Staphylococcus and Photobacterium) compared with the control group.Collectively,the results suggest that B.velezensis GPSAK4,B.subtilis GPSAK9(especially this strain),B.tequilensis GPSAK2 dietary supplementation at 1.0×10^(9)CFU/g has positive effects on the intestinal health of hybrid grouper via microbial composition modulation,thus enhancing the assimilation and absorption of nutrients to boost fish growth,immunity,and disease resistance.
文摘在盐度5、10、15、20、25、30条件下,以全人工配合饵料饲喂龙虎斑[鞍带石斑鱼（Epinephelus lanceolatus♂）×棕点石斑鱼（E.fuscoguttatus♀）]60 d,研究不同盐度对龙虎斑生长和摄食的影响。结果表明,不同盐度对龙虎斑生长的影响有统计学意义（P〈0.05）,盐度5-20组增长率、特定生长率均高于盐度25、30组,差异有统计学意义（P〈0.05）,盐度10组的增长率最高,为55.08%,盐度15组的特定生长率最大,为2.30%/d,盐度和龙虎斑生长速率的回归方程为K=0.000 09 S 4-0.006 S 3＋0.131 S 2-1.055 S＋4.832（R 2=0.984）;不同盐度对龙虎斑的摄食率和饵料系数影响有统计学意义（P〈0.05）,盐度15组的摄食率最高,为1.64%/d,其次为盐度10组,为1.60%/d,饵料系数在盐度15组最低,为0.820,其次为盐度10组,为0.827。因此,龙虎斑在低盐度条件下生长比高盐度快,摄食率高,饵料利用率高,最佳生长盐度为10-15。
