Optimization Alginate Aloe vera gel Aloe vera gels Bacilli Encapsulation Lactobacillus acidophilus Systems engineering alginate encapsulation Bifidobacterium Biomass Biomass productions Carbon Carbon and nitrogen Concentration ranges Economic production Encapsulated cell Encapsulation yields Engineering research FCCD-RSM FFD Fish Fish gelatin Fractional factorial designs Fructose Genipin Glucose Microencapsulation process Nitrogen