Optimization and application of probiotics complex for grouper based on dynamic model

Area of Science:

• Aquaculture
• Microbiology
• Genetics

Background:

• Grouper aquaculture faces challenges from disease and suboptimal growth.
• Developing effective probiotics requires careful strain selection and understanding microbial interactions.

Purpose of the Study:

• To develop and validate a multi-strain probiotic consortium for grouper aquaculture.
• To optimize probiotic formulation using microecological methods and modeling.

Main Methods:

• Screened five marine Bacillus strains for functional and safety traits.
• Utilized the generalized Lotka-Volterra (gLV) model and multiple linear regression for strain selection and interaction optimization.
• Conducted in vitro tests on grouper intestinal communities and a 42-day feeding trial with hybrid grouper (E. fuscoguttatus ♀ × E. lanceolatus ♂).

Main Results:

• Identified an optimal consortium of Bacillus subtilis, Bacillus megaterium, and Bacillus velezensis (1:1:1) with antagonism against Vibrio harveyi.
• The consortium enhanced gut microbiome stability, increased beneficial bacteria, and suppressed pathogens in grouper.
• Feeding trials showed the consortium significantly improved growth performance (weight-specific growth rate, feed intake) and disease resistance (survival rate).

Conclusions:

• The gLV model is effective for designing targeted probiotic consortia.
• The developed multi-strain probiotic offers a promising solution for enhancing grouper aquaculture sustainability and productivity.
• Probiotic supplementation reshaped the gut microbiome, promoting a healthier microbial environment.