BACKGROUND: The consumption of probiotics in aquaculture is constantly growing due to the numerous benefits conferred on the fish health. Degradation of probiotics in gastrointestinal tract is one of the most important challenges in probiotic efficacy. Encapsulating of probiotics within a physical barrier has been found to increase probiotic viability in fish gastrointestinal tract. Objectives: In this study the effect of encapsulation of Lactobacillus plantarum with alginate/chitosan nano particles in in vitro situation and their effects in Huso huso were evaluated. Methods: Firstly, in vitro probiotic potential including: pH and bile resistance, gastrointestinal juice tolerance was evaluated. Then effects of encapsulated probiotic were evaluated in Huso huso. 480 juvenile H. huso were randomly divided into four treatments in triplicates. Fish in T1 were fed with alginate/chitosan enriched free probiotic diet, T2 received encapsulated Lactobacillus plantarum, T3 received bacteria without any encapsulation and T4 received basic diet as a control group. All treatments were fed with experimental diets for 60 days and study lasted for 15 days with control diet in all fish. Fish samples were taken on days 30, 60 and 75 and bio chemically compared among the treatments. Results: Results of first phase of study showed that mostly all probiotic properties of encapsulated bacteria were more appropriate than control treatment (P<0.05). Encapsulation of bacteria in both procedures enhanced almost all immunological parameters compared to control treatment (P<0.05). Higher Ca and Mg of plasma were observed in fish fed with Lactobacillus plantarum nano/microencapsulated and alginate/chitosan at day 30 and 60, whereas decreased TRI of plasma was observed in fish fed with Lactobacillus plantarum nano/microencapsulated at day 30. Conclusions: It can be concluded that nano encapsulation of Lactobacillus plantarum with alginate/chitosan not only improved in vitro probiotic effects of L. plantarum, but also it can increase Biochemical parameters of H. huso and could improve the positive performance of probiotics activity.

Introduction: Immune-potentiating functions of Lactobacillus plantarum strains in the common carp were evaluated. Material and Methods: Fourteen days of feeding fish dry diet supplemented with the bacteria provided parameters of nonspecific humoral immunity (lysozyme, ceruloplasmin, γ-globulin, total protein levels, and serum bactericidal activity) and cellular immunity (pinocytosis, respiratory burst activity, and potential killing activity of organ phagocytes), as well as the proliferative response of organ lymphocytes stimulated with mitogens. The resistance of fish to infection with Aeromonas hydrophila was also determined. Results: Dietary supplementation with L. plantarum had a substantial influence on the activity of organ phagocytes, especially the potential killing activity of head kidney cells. A significant increase in the proliferative activity of LPS-stimulated B lymphocytes and in the levels of γ-globulins and total protein was observed. The supplemented diet conveyed higher resistance than the control diet as the cumulative fish mortalities after infection with A. hydrophila were 65% and 85%, respectively. Conclusion: The results indicate that dietary supplementation with L. plantarum stimulates the antibacterial resistance of common carp and may reinforce defence against bacterial infections, but further studies need to be conducted.

OBJECTIVE To culture Lactobacillus spp from veterinary probiotics and measure their in vitro oxalate-degrading capacity. SAMPLE 2 commercial veterinary probiotics containing Lactobacillus spp. PROCEDURES Lactobacillus spp were cultured anaerobically on selective deMan, Rogosa, Sharpe agar medium and subcultured for speciation by 16S rDNA gene sequencing. Isolates were inoculated into broth containing sodium oxalate (5 mg/L) and incubated anaerobically for 72 hours. An oxalate-degrading isolate of Lactobacillus acidophilus (American Type Culture Collection [ATCC] 53544) was the positive control sample; sterile broth containing a known quantity of sodium oxalate was the negative control sample. Oxalate concentrations were detected with ion chromatography. Oxalate degradation was assessed with Dunnett tests to detect differences in mean oxalate concentration for each isolate, compared with results for the negative control. RESULTS Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus casei or Lactobacillus zeae (too closely related to differentiate) were isolated from probiotic 1, and L plantarum was isolated from probiotic 2. Sequencing of the 16S rDNA gene confirmed 100% homology to type species. Lactobacillus acidophilus (ATCC 53544) and L acidophilus from probiotic 1 significantly decreased oxalate concentrations by 85.3 and 161.9 mg/L, respectively. Lactobacillus plantarum from probiotics 1 and 2 significantly increased oxalate concentrations by 56.1 and 36.1 mg/L, respectively. Lactobacillus casei did not alter oxalate concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Lactobacillus acidophilus isolates significantly reduced oxalate concentrations. In vivo studies are needed to determine whether probiotics containing L acidophilus decrease urine oxalate concentrations and reduce risk of urolith recurrence in dogs with a history of calcium oxalate urolithiasis.