Microencapsulation of Lactobacillus bulgaricus with alginate-chitosan improves probiotic potency in great sturgeon (Huso huso)

In this study, alginate and chitosan were used as encapsulation material via ionic gelation (IG) and internal emulsification (INE) methods to improve the efficacy of probiotic potency of Lactobacillus bulgaricus in Beluga (Huso huso) following dilatory administration of probiotics. Characterizations and ultrastructure of encapsulated bacteria were studied. Six hundred beluga (27.2 +/- 2.8 g) were divided into five groups in triplicates. Group 1 received alginate/chitosan without L. bulgaricus food; groups 2 and 3 were fed with a basal diet supplemented with L. bulgaricus encapsulated via INE or IG methods, respectively. Group 4 was fed with a basal diet supplemented with L. bulgaricus, and group five was fed with a basal diet. Characterization of microcapsules, zeta potential, ultrastructure, and encapsulation rate of L. bulgaricus showed a well-capsulated, homogenous, and stable product. The survival rate of bacteria in the simulated GIT situation showed a significant increase in the survival rate of encapsulated bacteria compared to other groups (P < 0.05). Most of the hemato-immunological parameters of H. huso following dietary application of L. bulgaricus significantly improved in INE and IG groups compared to the control group (P < 0.05). Although food supplementation with non-capsulated L. bulgaricus significantly promotes growth performance indices in Beluga, encapsulated bacteria with alginate/chitosan did not affect growth indices compared to this group (P > 0.05). In conclusion, microencapsulation via both INE and IG methods effectively protects L. bulgaricus in GI and consequently improved most of the hematological and immunological parameters compared to free capsule bacteria. Growth indices, conversely, were not affected by both encapsulation methods probably because of the anti-nutritional effects of chitosan.

Automated summary

In this study, alginate and chitosan were used to encapsulate Lactobacillus bulgaricus in Beluga using ionic gelation and internal emulsification methods. The encapsulated bacteria showed improved survival rates in simulated gastrointestinal conditions and resulted in significant improvements in hematological and immunological parameters. However, the encapsulation did not affect the growth indices of Beluga compared to non-encapsulated bacteria.