MANGO INDUSTRIAL RESIDUES AS A SOURCE FOR ENZYME INDUCTION IN Trichoderma harzianum: POTENTIAL FOR DENTAL BIOFILM DEGRADATION

Abstract

A polysaccharide extracted from mango (Mangifera indica L.) has been suggested as a new alternative for the induction of glucanase in Trichoderma harzianum. Glucanase can degrade glucans, the main constituent of cariogenic biofilms, such as those produced by Streptococcus mutans. Mango is one of the most consumed fruits in Brazil and its processing in the food industry is capable of generating waste that is discarded, such as the seed kernel and peel. In this context, the possibility of studying the bioactive properties of the industrial residues of this fruit can bring contributions to the areas of Health, Industry and Environment. Therefore, this project aims at evaluating the effect of the industrial residues of the mango (peel and seed kernel) as an enzyme-inducing source in T. harzianum, studying the effect of the enzymes produced by the fungus and the effect of glucanases isolated on cariogenic biofilm. Besides, the chemical structures of the fractions studied (peel and seed kernel), as well as the bacterial polysaccharides resulting from enzymatic degradation, will be elucidated. Polysaccharides of the mango (Tommy Atkins variety) epicarp (peel), mesocarp (pulp), endocarp (seed kernel) and seed cotyledons will be extracted, characterized and quantified. For this, the polymers will be added to a growth medium containing T. harzianum for induction of glucanases. After 192 hours of incubation, the medium will be centrifuged, and the supernatant containing the enzymes induced (enzyme extract) will be purified for the isolation of glucanases, using ion exchange chromatography and molecular weight exclusion, and its purity certified by denaturing electrophoresis gel. Pathogenic biofilms of S. mutans will be formed for 5 days on glass slides. On the 3rd day of the growth, the biofilms will be exposed to the following treatments (n=3): a) NaCl 0.9%, as negative control; b) 0.12% chlorhexidine digluconate solution, positive control; c) extract of T. harzianum enzymes induced by mango epicarp, mesocarp, endocarp or seed cotyledons polysaccharides; d) purified glucanases from T. harzianum induced by mango epicarp, mesocarp, endocarp or seed polysaccharides. The acidogenicity and bacterial viability of the biofilms will be determined, and the bacterial polysaccharides will be extracted, quantified and their chemical structure determined by gas chromatography associated with mass spectrometry and nuclear magnetic resonance. Polymer quantification data and microbiology analysis will be statistically analyzed by applying the most appropriate test for the replicates to be performed. The accepted level of significance will be 5%. To analyze the chemical structure results, the polysaccharides extracted from each biofilm after treatment will be pooled and compared to ensure the reliability of the results. It is expected that, instead of being a source of pollution, mango waste can be reused as a source of glucanase enzyme inducers and are readily available for the production of enzymes that would degrade oral biofilm. (AU)