Abstract: Nisin is a broad spectrum antimicrobial effective against Gram-positive bacteria. Antibacterial activity of Nisin is reduced when it is applied in food, due to binding with food matrix components. Encapsulation of Nisin in pectin-chitosan polyelectrolyte complex was prepared to protect Nisin from losing efficacy. Systematically, a number of parameters, pectin degree of esterification (DE), m (PE): m (CHI) mass ratio and solution pH were explored and their effect on the formation of stable polyelectrolyte nano complex colloid between pectin (PE) and chitosan (CS) was determined. Electrostatic interactions between carboxyl groups on pectin and amino groups on chitosan are confirmed by FTIR. The effects of DE of pectin on Nisin-loaded encapsulation properties were studied. Nanocapsules prepared by low methoxyl pectin (LPE) had higher encapsulation efficiency (EE) and loading capacity (LC) with smaller particle size, compared with those prepared by high methoxyl pectin (HPE). The largest EE is 65.9% when m (LPE): m(CHI) ratio was 20:15 and Nisin was 7 mg. Increasing amount of Nisin had a tendency to form nanocapsules with lower EE and higher LC and particle size. Release profile of Nisin from nanocapsules was affected by pH, more amounts of Nisin released at pH 3 than at pH 6. Encapsulated Nisin showed more active antibacterial activities against S. aureus than free Nisin. Encapsulation offers great promise to improve antibacterial effectiveness of Nisin.Abstract: Nisin is a broad spectrum antimicrobial effective against Gram-positive bacteria. Antibacterial activity of Nisin is reduced when it is applied in food, due to binding with food matrix components. Encapsulation of Nisin in pectin-chitosan polyelectrolyte complex was prepared to protect Nisin from losing efficacy. Systematically, a number of paramet...Show More
Abstract: Microbial exopolysaccharides (EPS) obtained from microbial sources, became simply available for a broad range of applications, especially for medicine and pharmaceutical industries. One of these EPS bacterial cellulose known as biocellulose (BC). BC is a pure extracellular cellulose, which accumulate outside the cells, produced by several species of microorganisms, like Gluconacetobacter; Achromobacter; Sarcina and Agrobacterium with a great number of applications. It is an organic unbranched polysaccharide, type β-1,4-glucan, composed of glucopyranose residues. Biocellulose is used as artificial skin and occlusive dressings to treat chronic wounds and to heal burns, in microsurgeries as artificial blood vessels, scaffolds in tissue engineering and many other applications. This work represents a review on this remarkably microbial biomaterial and thus an update of a collection of scientific data from original research between 1979 and 2016. The paper started on structural, composition, properties and characterization and biogenesis of this biopolymer, then it gives a synthesis on a variety of biomedical applications.Abstract: Microbial exopolysaccharides (EPS) obtained from microbial sources, became simply available for a broad range of applications, especially for medicine and pharmaceutical industries. One of these EPS bacterial cellulose known as biocellulose (BC). BC is a pure extracellular cellulose, which accumulate outside the cells, produced by several species o...Show More