Effects of Bacillus subtilis WB60 and Lactococcus lactis on Growth, Immune Responses, Histology and Gene Expression in Nile Tilapia, Oreochromis niloticus

Abstract

An eight-week feeding trial was conducted to evaluate the effects of a basal control diet (CON), Bacillus subtilis at 107 (BS7) and at 108 CFU/g diet (BS8), Lactococcus lactis at 107 CFU/g (LL7) and at 108 CFU/g diet (LL8), and oxytetracycline (OTC) at 4 g/kg diet on Nile tilapia. Fish with initial body weight of 2.83 ± 0.05 g (mean ± SD) were fed two times a day. Weight gain, specific growth rate, feed efficiency, protein efficiency ratio and lysozyme activity of fish fed BS8, LL8 and LL7 diets were significantly higher than those of fish fed CON diet (p < 0.05). Superoxide dismutase and myeloperoxidase activity of fish fed BS8, LL8, BS7, LL7 and OTC diets were significantly higher than those of fish fed CON diet. Intestinal villi length and muscular layer thickness of fish fed BS8, LL8 and LL7 diets were significantly higher than those of fish fed CON and OTC diets. Also, heat shock protein 70 (HSP70), interleukin (IL-1β), interferon-gamma (IFN-γ) and tumour necrosis factor (TNF-α) gene expression of fish fed BS8 and LL8 diets were significantly higher than those of fish fed CON diet. After 13 days of challenge test, cumulative survival rate of fish fed BS8 and LL8 diets were significantly higher than those of fish fed CON, BS7 and OTC diets. Based on these results, B. subtilis and L. lactis at 108 (CFU/g) could replace antibiotics, and have beneficial effects on growth, immunity, histology, gene expression, and disease resistance in Nile tilapia.

The Effects of Nisin-Producing Lactococcus lactis Strain Used as Probiotic on Gilthead Sea Bream (Sparus aurata) Growth, Gut Microbiota, and Transcriptional Response

“…Indeed, no structural modifications were detected in fish fed with diets supplemented with probiotic (diets B and C), in comparison to the control group fed diet A. In line with our results, other studies have shown that probiotics improve gut morphology, leading to an increase in intestinal absorption capacity (Batista et al, 2016;Won et al, 2020). In contrast, Cerezuela et al (2012; reported several negative effects related to the administration of probiotics in gilthead sea bream.…”

“…As mentioned previously, one of the most interesting effects of probiotics is the increase in the animals' growth performance (Sun et al, 2012;Nguyen et al, 2017;Won et al, 2020). In the present study, gilthead sea bream fed diets C and B, supplemented with high and low doses of L. lactis subsp.…”

Multifaceted applications of probiotic Bacillus species in aquaculture with special reference to Bacillus subtilis

“…2012; Won et al . 2020). Reports confirm that such probiotics can effectively stimulate immune system with elevation of specific and nonspecific immune responses (Salinas et al .…”

“…In a recent study, marked enhancement of growth performance (weight gain, specific growth rate, feed efficiency and protein efficiency ratio); immune responses (lysozyme activity, superoxide dismutase and myeloperoxidase activity); intestinal morphology (intestinal villi length and muscular layer thickness); expression of heat‐shock protein 70 and various cytokines such as interleukin (IL), interferon‐gamma (INF γ) and tumour necrosis factor (TNF); and more disease resistance has been reported in Nile tilapia, O. niloticus , by dietary administration of B. subtilis mixed with L. lactis at 1 × 10 8 CFU g −1 feed for 8 weeks (Won et al . 2020).…”

“…lactis and other microorganisms exerts synergistic beneficial effects on growth and nutrition, immunity and disease resistance of aquatic hosts (EI-Ezabi et al 2011;Mohapatra et al 2012;Won et al 2020). Reports confirm that such probiotics can effectively stimulate immune system with elevation of specific and nonspecific immune responses (Salinas In a recent study, marked enhancement of growth performance (weight gain, specific growth rate, feed efficiency and protein efficiency ratio); immune responses (lysozyme activity, superoxide dismutase and myeloperoxidase activity); intestinal morphology (intestinal villi length and muscular layer thickness); expression of heat-shock protein 70 and various cytokines such as interleukin (IL), interferongamma (INF c) and tumour necrosis factor (TNF); and more disease resistance has been reported in Nile tilapia, O. niloticus, by dietary administration of B. subtilis mixed with L. lactis at 1 9 10 8 CFU g À1 feed for 8 weeks (Won et al 2020). Stimulation of host immuno responses is believed to be one of the perforated mechanisms of probiotics, and aquatic hosts are no exception (Nayak 2010a).…”