Films of Chitosan and Aloe vera for Maintaining the Viability and Antifungal Activity of Lactobacillus paracasei TEP6

Abstract

The present study aimed to evaluate the effect of Aloe vera addition on the viability and antifungal activity of TEP6 (Lactobacillus paracasei) bacteria immobilized on chitosan films for 28 days. Different chitosan and A. vera proportions and carbon sources at several pH values were tested as formulations for supporting the microorganism. Bacterial viability was maintained in freshly made films, with values of 10.4, 10.8 and 10.9 log CFU·g−1 for the formulations containing 70% (T11), 100% (T8) and 100% (T16) of A. vera, respectively. The same formulations (T8, T11 and T16) maintained bacterial viability for 14 days of film storage with a loss to values of 9.5 log CFU·g−1. By applying a quarter fraction 25–2 experimental design with an array of five factors, the factors with the greatest influence on viability and antifungal activity were determined. The optimal conditions for viability were the formulation with 100% A. vera, pH 4.5 and 0.1 M glucose. The antifungal activity of fresh films was influenced by the formulation with 10 g·L−1 glycerol and 100% A. vera, showing a 60% inhibition of fungal (Colletotrichum gloeosporioides) growth. The films developed in this study may have the potential to be used as coatings on vegetal products susceptible to attack by Colletotrichum gloesporioides.

Recent development on physical and biological properties of chitosan-based composite films with natural extracts: A review

“…They reported that the film containing cinnamon oil showed maximum antimicrobial activity among the three oils against Aspergillus oryzae and Penicillium digitatum fungi than gram-positive (S. aureus) and gram-negative (E. coli) bacteria. Barragán-Menéndez et al 45 evaluated the effect of aloevera incorporated with chitosan to study the feasibility and antifungal activity of TEP6 (Lactobacillus paracasei) bacteria on chitosan films. They reported that maximum viability of the film can be seen with higher aloevera concentration and at pH 4.5.…”

Synthesis and Design of a Synthetic-Living Material Composed of Chitosan, Calendula officinalis Hydroalcoholic Extract, and Yeast with Applications as a Biocatalyst

“…23 Aloe vera was another plant used in the preparation of chitosan films, in this case, to maintain the viability and antifungal activity of Lactobacillus paracasei TEP6, a microorganism integrating into the material; this biomaterial has been used as a coating for vegetables to prevent the growth of the Colletotrichum gloeosporioides fungi. 24 Microbial biosynthesis uses different microorganisms to produce a large variety of industrial products for human interest. 25 Saccharomyces cerevisiae (S. cerevisiae) is a nonpathogenic yeast and the best-studied eukaryote.…”

“…In recent years, plant extracts have been used to modify the physicochemical properties of materials, enhancing their ability to integrate cells by increasing cell adhesion and cell viability within the material. , Calendula officinalis (C. officinalis) is an important medicinal plant with potential biological properties; its hydroalcoholic extract has been used to elaborate films with improved adhesion and viability for human fibroblasts as well as other eukaryotic cells such as Candida albicans …”

“…In recent years, plant extracts have been used to modify the physicochemical properties of materials, enhancing their ability to integrate cells by increasing cell adhesion and cell viability within the material. 23 , 24 Calendula officinalis ( C. officinalis ) is an important medicinal plant with potential biological properties; its hydroalcoholic extract has been used to elaborate films with improved adhesion and viability for human fibroblasts as well as other eukaryotic cells such as Candida albicans . 23 Aloe vera was another plant used in the preparation of chitosan films, in this case, to maintain the viability and antifungal activity of Lactobacillus paracasei TEP6, a microorganism integrating into the material; this biomaterial has been used as a coating for vegetables to prevent the growth of the Colletotrichum gloeosporioides fungi.…”

“…23 Aloe vera was another plant used in the preparation of chitosan films, in this case, to maintain the viability and antifungal activity of Lactobacillus paracasei TEP6, a microorganism integrating into the material; this biomaterial has been used as a coating for vegetables to prevent the growth of the Colletotrichum gloeosporioides fungi. 24 …”