Evaluation of Dietary Probiotic Bacteria and Processed Yeast (GroPro-Aqua) as the Alternative of Antibiotics in Juvenile Olive Flounder Paralichthys olivaceus

Abstract

We investigated the three probiotic bacteria and a processed yeast (GroPro-Aqua) as the replacers of antibiotics in juvenile olive flounder. A total of seven diets were used, that is, one basal or control (CON) diet; and six other diets, of which, three diets were prepared by supplementing probiotic bacteria such as Bacillus subtilis WB60 (BSWB60) at 1 × 108 CFU/g diet, Bacillus subtilis SJ10 (BSSJ10) at 1 × 108 CFU/g diet, and Enterococcus faecium SH30 (EFSH30) at 1 × 107 CFU/g diet; one diet with processed yeast (GRO) at 0.35% diet; and two other diets were supplemented with oxytetracycline (OTC) and amoxicillin (AMO) at 4 g/kg of each. Triplicate groups of fish (average 12.1 g) were fed one of the diets for eight weeks. At the end of the feeding trial, the fish that were fed the probiotic bacteria-supplemented diets had a significantly higher final weight, weight gain, and specific growth rate compared to the CON, OTC, and AMO diets. Fish that were fed the GRO diet had significantly higher feed efficiency and protein efficiency ratios than those of the fish that were fed the CON diet. Serum glutamic pyruvic transaminase, glutamic oxaloacetic transaminase, glucose, and total protein were not affected by the diets. Lysozyme activity in fish that were fed the BSSJ10, BSWB60, and EFSH30 diets were significantly higher compared to the CON and OTC diets, whereas myeloperoxidase activity of fish fed the BSWB60 and EFSH30 diets were significantly higher than those of fish fed the CON and AMO diets. Flounder growth hormone gene expressions of fish that were fed BSWB60 and GRO diets were significantly higher compared to the CON, OTC, and AMO diets. The interleukin-1β gene expression of fish that were fed the BSSJ10, BSWB60, EFSH30, OTC, and GRO diets was significantly higher than those of fish fed the CON diet. The interleukin-10 gene expression of fish that were fed the BSSJ10, EFSH30, and GRO diets was significantly higher than those of fish fed the CON and AMO diets. Posterior intestinal histology of fish showed significantly higher villi length in fish that were fed the BSSJ10, BSWB60, EFSH30, and GRO diets compared to the CON diet. After 15 days of challenge test with pathogenic bacteria Edwardsiella tarda, the cumulative survival rate of fish that were fed the BSSJ10, BSWB60, EFSH30, and GRO diets were significantly higher than those of fish that were fed the CON diet. Overall, the results indicate that dietary supplementation of B. subtilis (108 CFU/g diet), E. faecium (107 CFU/g diet), and processed yeast (GroPro-Aqua at 0.35% diet) could replace the antibiotics in terms of improving growth, immunity, gut health, and disease resistance in juvenile olive flounder.

The effects of two dietary synbiotics on growth performance, haematological parameters, and non-specific immune responses in Japanese eel (Anguilla japonica)

“…On the other hand, B. subtilis at 1 × 10 8 CFU g -1 with MOS did not show a significant 16 influence on the MPO activity of Japanese eel (Park et al 2020), suggesting that supplementation with the inclusion of B. subtilis at 1 × 10 7 CFU g -1 with MOS may be more effective for the Japanese eel. Interestingly, there was no significant difference in MPO activity of juvenile Olive Flounder (Paralichthys olivaceus) fed two strains of B. subtilis at 1 × 10 8 CFU kg -1 diet, E. faecium at 1 × 10 7 CFU g -1 , and an antibiotic-based diet (Choi et al 2022). Confirming earlier suggestions that the host-associated probiotics might be more effective, but an additional investigation is required (Ringø 2020).…”

Effect of Four Functional Feed Additives on Growth, Serum Biochemistry, Antioxidant Capacity, Gene Expressions, Histomorphology, Digestive Enzyme Activities and Disease Resistance in Juvenile Olive Flounder, Paralichthys olivaceus

“…The feed additives used in this experiment were a control (CON) without additive supplementation, taurine (TW, 0.5%), peptide (PT, 0.3%), mineral water (MW 0.217%), Gro-pro ® (GRO 0.35%), Gro-pro + taurine (GRO + TW 0.35% + 0.5%), Gro-pro + peptide (GRO + PT 0.35% + 0.3%), Gro-pro + mineral water (GRO + MW 0.35% + 0.217%) and oxytetracycline (OTC 0.5%). The dietary inclusion levels of four feed additives were based on previous studies, such as Choi et al [ 36 ] for Gro-pro ® (GroPro Aqua, Angel Yeast Co. Ltd., Yichang, China), which is a yeast-derived protein and nucleic acid-based commercial feed additive used as a growth and palatability enhancer in aquaculture, and Kim et al [ 25 ] and Jo et al [ 27 ] for taurine. Additionally, according to the manufacturer’s recommendation, peptide, which is rich in peptide, nucleotide, glutamic acid, amino acids and inositol (NuPro, Alltech Inc., Seoul, Republic of Korea), and laboratory-made mineral water (consisting of 95% water and 5% minerals such as Ca, P, Na, K, etc.…”

“…Furthermore, IMP and SSE were found to be easily obtainable from waste valorization processes, which would be economically feasible and involve fast production at lower costs. In a recent study, Choi et al [ 36 ] found that a dietary yeast-extracted nucleotide with probiotics could replace antibiotics in terms of improving growth, immunity, gut health and disease resistance in juvenile olive flounder. These single-cell protein meals have a remarkably high protein content, with a well-balanced essential amino acid profile that does not compromise growth performance, and improve gut health and reduce enteritis associated with high-soybean feeds without being detrimental to the growth, antioxidation or immunity of fish.…”

“…These single-cell protein meals have a remarkably high protein content, with a well-balanced essential amino acid profile that does not compromise growth performance, and improve gut health and reduce enteritis associated with high-soybean feeds without being detrimental to the growth, antioxidation or immunity of fish. All the mentioned feed additives have shown great potential to enhance the growth and immune responses of fish [ 21 , 31 , 35 , 36 ].…”

Brown Seaweed (Padina australis) Extract can Promote Performance, Innate Immune Responses, Digestive Enzyme Activities, Intestinal Gene Expression and Resistance against Aeromonas hydrophila in Common Carp (Cyprinus carpio)

“…In case of infection, chemotherapies are usually prescribed to relieve the impacts of A. hydrophila infection on common carp [ 8 ]. Although fish farmers are currently using some antibiotics for the treatment/control of this bacterial disease, a continuous supply of antibiotics can enhance bacterial resistance, environmentally hazardous factors, and food safety issues [ 9 , 10 ]. Hence, antibiotics may be substituted with ecologically safe feed additives such as probiotics/prebiotics, seaweeds, and herbal drugs [ 11 , 12 , 13 ].…”