Dietary supplementation withBacillusspecies improves growth, intestinal histomorphology, innate immunity, antioxidative status and expression of growth and appetite‐regulating genes of Nile tilapia fingerlings

Abstract

This study assessed the impact of dietary supplementation of single-and multi-strain Bacillus-based probiotics on growth performance, intestinal morphometry, blood parameters, immune-oxidative status and transcriptomic response of Nile tilapia for 60 days. Fish (N = 150, 1.632 ± 0.035 g) were allocated into five experimental groups:(1) Control group (CG) that was fed on a basal diet; (2) Eco. 0.01%, received basal diet with 0.1 g/kg Ecobiol; (3) Eco. 0.02%, received basal diet with 0.2 g/kg Ecobiol;(4) Pro-F FMC 0.001%, received basal diet with 0.001 g/kg Sanolife PRO-F FMC; (5) Pro-F FMC 0.002%, received basal diet with 0.002 g/kg Pro-F-FMC. Fish received Pro-F FMC 0.002% displayed higher growth performance than CG (p < 0.05), while Pro-F FMC 0.001% exhibited the highest intestinal weight. Sanolife PRO-F FMC supplementation improved intestinal villi length and goblet cell number while decreased inter-villi space (p < 0.05). The best haemoglobin, haematocrit and monocyte per cent were observed in Pro-F FMC 0.001%, whereas Pro-F FMC 0.002% revealed the best leukocyte, lymphocyte and neutrophil contents. Pro-F FMC-supplemented groups showed better phagocytic activity, phagocytic index and lysozyme activity than Ecobiol-supplemented groups and CG. Pro-F FMC 0.001% enrichment induced the highest upregulation level of NPYα, AgRp-2, ghrelin and GH-1, whereas Pro-F FMC 0.002% significantly upregulated IGF-1 and IGF-2 gene expression. Eco. 0.02% induced the highest upregulation level of orexin and galanin gene expression.Conclusively, dietary enrichment with single-or multi-strain Bacillus-based probiotics is likely to improve growth, immunological parameters and transcriptomic response of Nile tilapia.

Effect of probiotic Bacillus spp.-supplemented feed on the growth, length-weight relationship, and condition factor of Nile tilapia (Oreochromis niloticus)

“…Previous studies also reported a significant effect of Bacillus spp. on growth, disease resistance, and hematological parameters of Nile tilapia (Soltan et al 2016;Sutthi et al 2018;Elsabagh et al 2018;Kuebutornye et al 2020;Won et al 2020;Ghalwash et al 2021) and other aquatic species (Hauville et al 2016;Munir et al 2016;da Paixão et al 2017;Kong et al 2017;Wang et al 2017;Amoah et al 2021;Saravanan et al 2021). In this present study, the effect of two previously isolated Bacillus spp.…”

Combined effect of a mixture of Bacillus species and vaccination on haemato‐biochemical parameters, immune response and transcriptomic changes of Nile tilapia challenged with Streptococcus iniae

“…Death specificity was detected using re‐isolation of S. iniae pathogen from freshly dead fish for two weeks (the length of the post challenge observation period), mortalities were monitored, and the relative level of protection (RLP) was performed according to the rules of Diab et al, 2021; Newman and Majnarich (1982). Liver samples were also collected after 24 hours post challenge from each triplicate after the fish were previously anaesthetized with clove oil, then liver samples were instantly shocked in a liquid nitrogen, and stored at −80°C for further RNA extraction (Ghalwash et al, 2022).…”

“…To determine the specificity of the PCR products, dissociation curve analyses were performed. A geometric average of two tilapia reference genes (β-actin and UBCE) was used to standardize quantitative RT-PCR data (Ghalwash et al, 2022).…”

“…Probiotic bacteria produce bacteriostatic and bactericidal molecules (bacteriocins, bacteriolytic enzymes, siderophores, hydrogen peroxide, organic acids, proteases and lysozymes) that could protect from pathogenic microbial populations (Dahiya, 2020; Dahiya et al, 2012; Ghalwash et al, 2022). Probiotics also produce certain substances that act as antagonists for quorum‐sensing mechanisms, improved immunity, increasing phagocyte and macrophage activities and antibody levels (Zorriehzahra et al, 2016).…”

“…Fundamentally, probiotics stimulate both the general innate and cellular immune systems of fish using an increase in the expression of immune‐related cytokines (Beck et al, 2015). Also, they modulate phagocytic and lysozyme activity, respiratory burst and increase immune cell numbers, including total leukocytes, lymphocytes and monocytes (Ghalwash et al, 2022). Furthermore, probiotics elicit changes in cell physiology and maturation such as improvement of neutrophil adherence capacity, migration of neutrophils, and plasma bactericidal activity (Newaj‐Fyzul & Austin, 2015; Soltani et al, 2019).…”