Preparation of pH-sensitive carboxymethyl cellulose/chitosan/alginate hydrogel beads with reticulated shell structure to deliver Bacillus subtilis natto.

pH-sensitive hydrogels have been applied in delivering probiotics and drugs. However, pH sensitivity has been found to be contradictory with structural stability in hydrogel preparation. In this work, a novel strategy based on two systems of sodium carboxymethyl cellulose (CMC)/chitosan (CS) and sodium alginate (SA)/calcium chloride was designed to construct a reticulated shell structure stable for 3 h in simulated gastric fluid (pH 1.

Inhibition of nattokinase against the production of poly (γ-glutamic Acid) in Bacillus subtilis natto.

Objective: To study the effect of nattokinse (NK) on the synthesis of poly(γ-glutamic acid) (γ-PGA) in Bacillus subtilis natto.

Results: γ-PGA yield significantly decreased as NK was added in the original medium. With the increment of NK dosage, the yield decreased increasingly, but biomass increased instead of decreasing.

Fabrication of a porous chitosan/poly-(γ-glutamic acid) hydrogel with a high absorption capacity by electrostatic contacts.

A porous chitosan (CS)/poly-(γ-glutamic acid) (γ-PGA) hydrogel was prepared by polymerization by electrostatic contacts of CS with γ-PGA without linker. The porosity of the hydrogel remarkably depends on γ-PGA content, pH regulator, and drying way. The optimization of them had given the hydrogel a high swelling capacity of 1398%, 11-fold higher than that of neat CS hydrogel.