페이지 정보작성자 : 생물의소재공학 날짜 : 작성일14-12-02 11:33 조회 : 1,141회
- Application of Chitosan-alginate Microspheres for the Sustained Release of Bacteriophage in Simulated Gastrointestinal Conditions.pptx (1.4M) 53회 다운로드 DATE : 2014-12-02 11:33:59
This study was designed to evaluate the acid stability, release property, and antimicrobial efficacy of Escherichia coli O157:H7 bacteriophages encapsulated in chitosan-alginate microspheres under the simulated gastric and intestinal conditions. E. coli O157:H7 bacteriophages, belonging to Myoviridae family, were isolated from chicken fecal sample. The susceptibility of bacteriophages were evaluated at various pH levels ranging from 2 to 8. The acid stability of bacteriophage-encapsulated chitosan-alginate microspheres was evaluated at 37oC for 1 h in the simulated gastric conditions (pH 2.0 and pH 2.5). The release and lytic activity of free and microencapsulated bacteriophages were examined at 37oC for 6 and 10 h, respectively, in the simulated intestinal conditions (pH 7.5). The bacteriophages isolated were stable at the pH above 4 in trypticase soy broth (TSB). The chitosan-alginate microspheres exhibited protective effect on the viability of bacteriophages in the simulated gastric conditions at pH 2.0 and pH 2.5, showing 4.8 and 5.6 log PFU/ml, respectively, after 1 h of incubation at 37oC. The release rate of bacteriophages from microspheres gradually increased up to 65% (5.7 log PFU/ml) in the simulated intestinal condition (pH 7.5) after 6 h of incubation at 37oC. The lytic efficacy of chitosan-alginate encapsulated bacteriophages against E. coli O157:H7 was significantly maintained in the simulated intestinal conditions to 10 h of incubation (1.3 log reduction) when compared to free bacteriophages (0.3 log reduction). The chitosan-alginate microspheres effectively protected bacteriophages against gastric acids and provided the sustained release of bacteriophages in the simulated intestinal conditions. The results suggest that the chitosan-alginate microspheres can be used as a reliable delivery system for bacteriophages.