EFFECT OF CHITOSAN AT DIFFERENT CONCENTRATIONS ON ANTIBACTERIAL ACTIVITY OF E. COLI ON ALGINATE BEADS EMPLOYED ON CRYOPRESERVATION

CATARINA F. FERNANDES; ALINE SCHNEIDER TEIXEIRA; MANUELA PINTADO; ANTONIO D. MOLINA-GARCÍA

Porto

Congreso; 11th International Conference of the European Chitin Society-EUCHIS 2013; 2013

European Chitin Society

Chitosan has been evaluated for various uses in food, medical, pharmaceutical, agricultural and chemical industries because of its non-toxic, biocompatible, mucoadhesive, and biodegradable properties, its high protein affinity and easy derivatization; moreover, it is worldwide available and inexpensive since it is derived from chitin, a by-product of the fishing industry and, actually, one of the most common natural polysaccharides. Calcium alginate gel beads readily interchange solutes with the bulk solution and water with the surrounding media. The transfer properties are often critical for its use, either for its stability and preservation or textural modulation, or for the convenient treatment of contained tissues for cryopreservation. In these cases, the antimicrobial protection conferred by chitosan can be also of great interests, as often cultivation and growth after cryopreservation can be impaired by microbial contamination. Alginate beads can, finally, be used as a model of food (and other substrates) behavior. Microbial proliferation is often a surface affair and gel beds can constitute a suitable model for the study of the interface microbial growth and, in this case, be helpful to study the mode of action of chitosan towards microorganisms. With the purpose of study the possible application of chitosan to both protect against microbial-derived damages and to consider permeability modulation on alginate gel beads employed in cryopreservation, the effect of chitosan treatments on the proliferation of E. coli on these beads has been evaluated. Results obtained suggest a promising utility of this polysaccharide for this purpose.