Effect of Probiotics on the Haematological Parameters of Indian Magur (Clarius batrachus L.)

Effects of probiotics on growth, survival, and intestinal and liver morphometry of Gangetic mystus (Mystus cavasius)

The usage of probiotics proved advantageous in aquaculture due to its positive impact on fish growth, immune response and environment. This study was aimed to assess the effects of probiotics on growth, survival and histometry of intestine and liver in Gangetic mystus (Mystus cavasius) using two separate experiments for a period of 8 weeks (in aquaria) and 16 weeks (in earthen ponds). Three different probiotic treatments were incorporated i.e. commercial probiotic one; CP-1 (T1), commercial probiotic two; CP-2 (T2), Lab developed (Lab dev.) probiotic (T3) including a control. The results indicated that the probiotics usage especially Lab dev. probiotic (T3) significantly improved the growth parameters such as weight gain (g) and specific growth rate (SGR, %/day) as well as ensured better feed conversion efficiency. Zero mortality was observed in aquaria whereas probiotic application enhanced survivability in earthen ponds. Moreover, all probiotic treatment exhibited positive results for different histo-morphometric features of intestine and liver. Mucus secreting goblet cells and fattening of mucosal fold increased significantly with probiotic usage. The amount of regular shaped nucleus was maximum in T3 with least intra cellular distance between liver tissues in earthen ponds. The greatest value for hemoglobin with lowest glucose level was observed in T3 as well. Furthermore, probiotic ensured low concentration of ammonia during culture. Overall, it was anticipated that the application of probiotics in Gangetic mystus culture resulted positive effect on its growth, feed utilization, survivability, histo-morphometry, immunity and hematological parameters.

Assessment of Thepax and Bio Boost for promoting microbial growth in common carp intestines Cyprinus carpio

The study aimed to evaluate the effect of Thepax and BioBoost as food additives on the microorganisms in the intestines of fish. From March 4 to October 22, the total number of common carp was 900 fish with an average weight of 163.41 ±10.16 g and a density of 100 fish/cage; three replicates were used for each treatment. The fish were fed three times daily. The included T1(0%additive), T2(1g/kgThepax)and T3 (1 g/kgBioBoost). The highest final weight value is Thepax treatment (2209.34 g), followed by Bio Boost and control. Microorganisms showed significant differences (P<0.05) in T2 for Lactobacillus sp. (10² x 65 CFU/ml) followed by T3 (10² x 55 CFU/ml) and control T1 (10² x 23 CFU/ml), also for Cellulomonas sp. in T2 (10² x 54 CFU/ml) followed by T3 (10² x 39 CFU/ml) and control T1 (10² x 7 CFU/ml). At the same time, Aeromonas sp. bacteria was higher in T1 (10² x 34 CFU/ml) over the treatments of T2 and T3 (10² x 2 CFU/ml) for both. We concluded the best additive was 1 g of Thepax / kg of feed in the recommended diets for common carp. Keywords: Thepax; Additives; Microorganisms; Intestines; Bacteria; Lactobacillus; Endo Bio Boost

Gut microbiome modulation mediated by probiotics: Positive impact on growth and health status of Labeo rohita

The current study was targeted to determine the effect of probiotics on the growth, physiology, and gut microbiology of Labeo rohita fingerlings. One hundred and twenty fishes were divided into four dietary groups, each in triplicate for a feeding trial of 90 days. These treatments included T0 (control, basal diet) used as the reference, and three probiotic-supplemented diets represented as Tbc (Bacillus cereus), Tgc (Geotrichum candidum), and Tmc (B. cereus and G. candidum). The probiotics were supplemented at a level of 1 × 10⁹ CFU/g feed. Fishes nurtured on probiotic-added diet showed significantly high physiological improvement (p < 0.05) in terms of growth, feed utilization capacity, hematological profile, and digestive enzymes as compared to control. The fish were subjected to a challenge test after a 90-day feeding trial. The Tmc exhibited maximum fish growth when challenged by Staphylococcus aureus and showed fish survival when compared to control, in which fish mortality was examined. Fish gut microbial composition was modulated by probiotic treatments, especially in Tgc and Tmc as compared to control. The absence of opportunistic pathogens such as Staphylococcus saprophyticus and Sporobolomyces lactosus and detection of lower levels of Trichosporon and Cryptococcus in treated groups indicate the gut modulation driven by applied probiotics. The G. candidum QAUGC01 was retrieved in yeast metagenomics data, which might be due to the production of polyamines by them that facilitated adherence and consequent persistence. In conclusion, it can be suggested that the probiotic-supplemented diet could enhance fish growth and feed efficiency through community modulation and digestive enzymes, which could be a milestone in local aquaculture.

Gut probiotic bacteria of Barbonymus gonionotus improve growth, hematological parameters and reproductive performances of the host

This study aimed to isolate and identify probiotic bacteria from the gut of Barbonymus gonionotus and evaluate their effects on growth, hematological parameters, and breeding performances of the host. Five probiotic bacteria viz. Enterococcus xiangfangensis (GFB-1), Pseudomonas stutzeri (GFB-2), Bacillus subtilis (GFB-3), Citrobacter freundii (GFB-4), and P. aeruginosa (GFB-5) were isolated and identified using 16S rRNA gene sequencing. Application of a consortium of probiotic strains (1-3 × 1.35 × 109 CFU kg-1) or individual strain such as GFB-1 (1.62 × 109 CFU kg-1), GFB-2 (1.43 × 109 CFU kg-1), GFB-3 (1.06 × 109 CFU kg-1), GFB-4 (1.5 × 109 CFU kg-1) or GFB-5 (1.43 × 109 CFU kg-1feed) through feed significantly improved growth, histological and hematological parameters and reproductive performances of B. gonionotus compared to untreated control. Moreover, the application of these probiotics significantly increased gut lactic acid bacteria and activities of digestive enzymes but did not show any antibiotic resistance nor any cytotoxicity in vitro. The highest beneficial effects on treated fishes were recorded by the application of GFB-1, GFB-2, GFB-3, and a consortium of these bacteria (T2). This is the first report of the improvement of growth and health of B. gonionotus fishes by its gut bacteria.

Beneficial effects of dietary probiotics mixture on hemato-immunology and cell apoptosis of Labeo rohita fingerlings reared at higher water temperatures

Probiotics play an important role in growth increment, immune enhancement and stress mitigation in fish. Increasing temperature is a major concern in present aquaculture practices as it markedly deteriorates the health condition and reduces the growth in fish. In order to explore the possibilities of using probiotics as a counter measure for temperature associated problems, a 30 days feeding trial was conducted to study the hemato-immunological and apoptosis response of Labeo rohita (8.3±0.4 g) reared at different water temperatures, fed with or without dietary supplementation of a probiotic mixture (PM) consisting of Bacillus subtilis, Lactococcus lactis and Saccharomyces cerevisiae) (10¹¹ cfu kg⁻¹). Three hundred and sixty fish were randomly distributed into eight treatment groups in triplicates, namely, T1(28°C+BF(Basal feed)+PM), T2(31°C+BF+PM), T3(34°C+BF+PM), T4(37°C+BF+PM), T5(28°C+BF), T6(31°C+BF), T7(34°C+BF) and T8(37°C+BF). A significant increase (P<0.01) in weight gain percentage was observed in the probiotic fed fish even when reared at higher water temperature (34–37°C). Respiratory burst assay, blood glucose, erythrocyte count, total serum protein, albumin, alkaline phosphatase and acid phosphatase were significantly higher (P<0.01) in the probiotic fed groups compared to the non-probiotic fed groups. A significant (P<0.01) effect of rearing temperature and dietary probiotic mixture on serum myeloperoxidase activity, HSP70 level and immunoglobulin production was observed. Degree of apoptosis in different tissues was also significantly reduced in probiotic-supplemented groups. Hence, the present results show that a dietary PM could be beneficial in enhancing the immune status of the fish and also help in combating the stress caused to the organism by higher rearing water temperature.

Probiotics in fish and shellfish culture: immunomodulatory and ecophysiological responses

Aquaculture is emerging as one of the most viable and promising enterprises for keeping pace with the surging need for animal protein, providing nutritional and food security to humans, particularly those residing in regions where livestock is relatively scarce. With every step toward intensification of aquaculture practices, there is an increase in the stress level in the animal as well as the environment. Hence, disease outbreak is being increasingly recognized as one of the most important constraints to aquaculture production in many countries, including India. Conventionally, the disease control in aquaculture has relied on the use of chemical compounds and antibiotics. The development of non-antibiotic and environmentally friendly agents is one of the key factors for health management in aquaculture. Consequently, with the emerging need for environmentally friendly aquaculture, the use of alternatives to antibiotic growth promoters in fish nutrition is now widely accepted. In recent years, probiotics have taken center stage and are being used as an unconventional approach that has numerous beneficial effects in fish and shellfish culture: improved activity of gastrointestinal microbiota and enhanced immune status, disease resistance, survival, feed utilization and growth performance. As natural products, probiotics have much potential to increase the efficiency and sustainability of aquaculture production. Therefore, comprehensive research to fully characterize the intestinal microbiota of prominent fish species, mechanisms of action of probiotics and their effects on the intestinal ecosystem, immunity, fish health and performance is reasonable. This review highlights the classifications and applications of probiotics in aquaculture. The review also summarizes the advancement and research highlights of the probiotic status and mode of action, which are of great significance from an ecofriendly, sustainable, intensive aquaculture point of view.