title: Dietary administration of Bacillus subtilis HAINUP40 enhances growth, digestive enzyme activities, innate immune responses and disease resistance of tilapia, Oreochromis niloticus.
abstract: The probiotic properties of Bacillus subtilis HAINUP40 isolated from the aquatic environment, and the effects of dietary administration of B. subtilis HAINUP40 on the growth performance, intestinal probiotic recovery, digestive enzyme activities, innate immunity and disease resistance of tilapia (Oreochromis niloticus) were evaluated. The probiotic properties investigated include tolerance to simulated gastrointestinal stress, auto-aggregation, cell surface hydrophobicity and extracellular enzyme production. The cell number of B. subtilis changed little after 4 h in simulated gastric fluid at pH = 2.0, 3.0, 4.0 and simulated intestinal fluid at pH = 6.8.B.subtilis HAINUP40 revealed strong auto-aggregation property (34.6-87.0%) after 24 h incubation period. It exhibited significant cell surface hydrophobicity in xylene (28.8%) and chloroform (41.3%) and produced extracellular proteases and amylase. After tilapia (mean weight = 95 ± 8 g) were fed with a diet containing 108cfu/g B. subtilis HAINUP40, their final body weight, percent weight gain (PWG), specific growth rate (SGR), total antioxidant capacity (T-AOC) and serum superoxide dismutase (SOD) increased significantly (p < 0.05) after 8 weeks; feed conversion rate (FCR) is significantly lower (p < 0.05) after 8 weeks; the protease and amylase activity in the digestive tract increased significantly (p < 0.05) after 4 and 8 weeks; and respiratory bursts and serum lysozyme activity increased significantly (p < 0.05) after 2 weeks. Moreover, being challenged with pathogenic Streptococcus agalactiae for 2 weeks, the relative percent survival (RPS%) is 52.94%. The results of this study strongly suggest that dietary supplement of B. subtilis HAINUP40 can effectively enhances the growth performance, immune response, and disease resistance of Nile tilapia.
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Haitian
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Shifeng
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Guo
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Zhenjie
authors.initials: Z
authors.lastname: Cao
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Yongzheng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Shubin
authors.initials: S
authors.lastname: Liu
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China.
authors.forename: Weiliang
authors.initials: W
authors.lastname: Guo
authors.affiliation: Key Laboratory of Tropical Biological Resources of Ministry of Education, College of Marine Sciences, Hainan University, Haikou 570228, PR China. Electronic address: zychnu@163.com.
authors.forename: Yongcan
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001412:Bacillus subtilis / Q000737:chemistry*; D023681:Cichlids / Q000254:growth & development / Q000276:immunology / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D060467:Disease Resistance; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology; D019936:Probiotics; D011897:Random Allocation; D013290:Streptococcal Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D013292:Streptococcus agalactiae / Q000187:drug effects / Q000502:physiology
keywords: Bacillus subtilis HAINUP40; Digestive enzyme activity; Growth; Innate immunity; Protection; Tilapia (Oreochromis niloticus)