Open AccessPotential of indigenous Bacillus spp. as probiotic feed supplements in an extruded low‐fish‐meal diet for juvenile olive flounder, Paralichthys olivaceus
Author(s) -
Niu KaiMin,
Khosravi Sanaz,
Kothari Damini,
Lee WooDo,
Lee BongJoo,
Lim SangGu,
Hur SangWoo,
Lee SangMin,
Kim SooKi
Publication year - 2021
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/jwas.12724
Subject(s) - olive flounder , paralichthys , biology , bacillus amyloliquefaciens , bacillus licheniformis , probiotic , streptococcus iniae , bacillus subtilis , food science , fish meal , flounder , feed conversion ratio , zoology , juvenile , prebiotic , fishery , fish <actinopterygii> , fermentation , ecology , bacteria , endocrinology , genetics , body weight
A 12‐week feeding trial was designed to assess the probiotic potential of indigenous Bacillus amyloliquefaciens and/or Bacillus subtilis singly or in combination with Bacillus licheniformis in an extruded feed for olive flounder ( Paralichthys olivaceus ) juveniles. A high fish meal (FM) diet (control) and a low‐FM diet containing an alternative protein blend (30% FM replacement, FM30) were formulated. Three other experimental diets were prepared by inclusion of B. amyloliquefaciens (BA), B. subtilis (BS), or a mixture of B. amyloliquefaciens , B. subtilis , and B. licheniformis (BASL) into FM30 diet, with a final concentration of 10 6 CFU/g diet. Results indicated that the FM30 diet was well tolerated by flounder, and the overall performance was not affected by dietary treatments. Lysozyme activity and total immunoglobulin level were significantly reduced in flounders when fed with the FM30 diet compared with the BASL and BA diets, respectively. The Bacillus additives neither enriched the relative abundance of the corresponding Bacillus spp. in the relevant gut microbiota of olive flounder nor modulated the presumptive gene functions of the gut microbiome. Despite the absence of growth‐promoting effect, the tested probiotics could still be economically viable for use as immunostimulants in commercial flounder diets with partial FM replacement.