Adsorption of Lactobacillus acidophilus on attapulgite: Kinetics and thermodynamics and survival in simulated gastrointestinal conditions

In the present study, we investigated the optimum adsorption conditions, adsorption characteristics and surviva of Lactobacillus acidophilus adsorbed on attapulgite (AIT). Results of single factor experiments showed that the optimum adsorption parameters were AlT concentration of 10%, initial pH of 6.5 and temperature of 35 degrees C. From the static experiments of adsorption characteristics, we found that the experimental data were fitted best to the pseudo-secondorder kinetics and Langmuir isotherm models, and the adsorption was a spontaneous and endothermic process. Bacteria survival test showed that the microencapsulated L. acidophilus stored at -18 degrees C for 30 days achieved the highest survival rate (83.2% +/- 5.8) and obtained better protection at simulated conditions of gastric pH and at high bile salt concentrations when compared with free bacteria. The study demonstrated that microencapsulation of L. acidophilus in ATT was an effective technique of protection against low-temperature injury and under simulated gastrointestinal environment. (C) 2016 Elsevier Ltd. All rights reserved.