Combined effects of dietary malic acid andBacillus subtilison growth, gut microbiota and blood parameters of Nile tilapia (Oreochromis niloticus)

Abstract

The study investigated effect of dietary supplementation with malic acid, Bacillus subtilis and a mixture of the two (3 × 2 factorial trial) on Nile tilapia (Oreochromis niloticus) health. Treatment groups (T1-T6) were fed diets containing three levels of malic acid bacterial count in the gut and faeces was detected in fish from group T6. The values of haematocrit, haemoglobin, red blood cells, white blood cells, total protein, albumin and globulin were significantly higher (p < .05) in fish from groups T4 and T6 (diets supplemented with malic acid and B. subtilis). As compared to the control fed fish, te mixture of these substances are promising as immune enhancher in aquacultured fish. K E Y W O R D SBacillus subtilis, blood parameters, growth, gut microbiota, Nile tilapia, organic acid | INTRODUCTIONMicrobial balance and proper pH in the digestive tract eliminate pathogenic microorganisms. This is necessary to maintain fish health in a satisfactory state and to achieve expected production levels.Over the last decade, research has focused on the application of probiotics and prebiotics to replace antibiotic growth promoters in the fish farming industry (Irianto & Austin, 2002;Yanbo & Zirong, 2006) and to enhance the growth and health of the host (Gatesoupe, 1999;Kesarcodi-Watson, Kaspar, Lategan, & Gibson, 2008).Most commercial probiotics currently being tested in aquaculture are lactic acid bacteria (e.g., Lactobacillus), the genus Bacillus, photosynthetic bacteria (e.g., Rhodobacter sphaeroides) and the yeasts foods as a flavour enhancer and for pH (1% malic acid solution is about 2.3) and microbial control, because it inhibits the growth of pathogenic bacteria and pathogenic fungi (Ricke, 2003). An exceptionally valuable nutritional property of this acid is that after oral administration, it stimulates the secretion of gastric juices and increases peristalsis. Small doses of malic acid have prebiotic properties, stimulating the development of non-pathogenic, acidophilic and saprophytic bacteria whereas at higher doses it can exhibit bacteriostatic and bactericidal properties (Salou, Leroy, Goma, & Pareilleux, 1991).An extensive review of the literature on this topic revealed that there are no reports on the in vivo kinetics of probiotic bacterial growth in the presence of organic acids. In in vitro studies, Lactobacillus plantarum exhibited better growth in the presence of malic acid as compared to the control group (Passos, Fleming, Hassan, & McFeeters, 2003).Therefore, in the authors' opinion, the current study is innovative and facilitates a better understanding of the interactions occurring among probiotics and malic acid in the gastrointestinal tract of fish. In summation, the aim of the current investigation was to assess the dietary inclusion of malic acid, Bacillus subtilis or a mix of the two on the growth performance, feed utilization, gut microbiota and haematological and biochemical blood parameters of Nile tilapia (Oreochromis niloticus;Linnaeus, 1758). After carp, the tilapia species c...

Dietary trans‐cinnamic acid application for rainbow trout (Oncorhynchus mykiss): II. Effect on antioxidant status, digestive enzyme, blood biochemistry and liver antioxidant gene expression responses

“…In the present study, it was found that dietary TrCin supplementations resulted in a decline of the stomach and intestinal pH levels at 4 hr postfeeding. This finding was consistent with previous reports, which noted that organic acid reduced stomach or gut pH in fish (Hassaan et al, ; Koh, Romano, Zahrah, & Ng, ; Ng et al, ). Organic acids decreased the pH value of experimental diets steadily, but they did not always create a significant effect on stomach and/or gut pH (Ng & Koh, ).…”

“…Some reports demonstrated that organic acids (citric, malic, acetic, formic, etc.) can accelerate growth and feed utilization of some fish species without affecting biochemical compositions and body indices of fish (Castillo, Rosales, Pohlenz, & Gatlin, ; Hassaan et al, ; Hoseinifar et al, ; Ng & Koh, ). These different results might be attributed to variations in the experimental conditions, feeding periods, organic acid types, fish size and fish species, or a combination of these factors.…”

“…Furthermore, they can facilitate feed digestion and absorption by chelating various cations and increasing activities of some digestive enzymes for animals (Chen et al, ; Lala, Oso, Okwelum, Ajao, & Adegbenjo, ). Recently, the inclusion of several organic acids or their salts alone or in combination in fish feed has yielded fruitful results on growth performance, feed utilization and disease resistance (Hassaan, Soltan, Jarmołowicz, & Abdo, ; Ng & Koh, ; Ng, Koh, Sudesh, & Siti‐Zahrah, ; Yilmaz, ; Yilmaz, Ergün, & Yıgıt, ; Yilmaz, Sova, & Ergün, ; Yilmaz, ).…”

Performance of Oreochromis niloticus in recirculating aquaculture systems at different levels of daily protein intake

“…Azim and Little, () found levels of 55% protein, 26% crude lipid and 17% ash in a juvenile O. niloticus (wet weight, clean water, 35% of protein in feed). Hassaan, Soltan, Jarmołowicz, and Abdo () described tilapia (whole body) with sizes of 34.1–38.8 g and supplemented the basal diet with Bacillus subtillis ; and the malic acid values of protein were 57.6%–62.2%, the crude lipid values were 17.0%–21.8% and the ash contents were 13.4%–15.0%. Mansour, Omar, Srour, and Yousef () determined values (wet weight) of 15.8%–17.0% protein, 6.9%–7.4% crude lipids and 3.3%–3.9% ash for juvenile tilapia (38.7–49.9 g).…”

Dietary supplementation with Bacillus subtilis LT3‐1 enhance the growth, immunity and disease resistance against Streptococcus agalactiae infection in genetically improved farmed tilapia, Oreochromis niloticus

“…Bacillus species, used as probiotics, contain B. subtilis , B. cereus , B. coagulans , B. clausii and B. licheniformis (Jeon et al, ). Among the probiotic candidates, B. subtilis , one of the most studied probiotics in fish, has been supplemented extensively in fish diets because of its various beneficial traits (Hassaan, Soltan, Jarmołowicz, & Abdo, ). Bacillus subtilis was reported to enhance immune responses and disease resistance, and positively affect the activities of digestive enzymes, anti‐inflammatory and antioxidant capacity in many cultured fish (Addo et al, ; Cerezuela, Guardiola, Gonzalez, Meseguer, & Esteban, ; He et al, ; Zaineldin et al, ).…”