Estudo do potencial biotecnológico de polissacarídeos de parede celular, produzidos por leveduras isoladas do semi-árido baiano

Abstract

The β-D-glucans and α-D-mannans are structural polysaccharides constituting the cell wall of yeasts and fungi which may be found in other microorganisms such as bacteria, and also on plants and cereals. The degree of branching and the nature of connection (1→4, 1→6 and 1→3) these polysaccharides also differ from each other. Several applications can be assigned the glucans and mannans, depending on its type, can act as immunomodulators. Several papers have been published, proving the ability of these polysaccharides stimulate macrophages to produce cytokines. Another application of these polysaccharides is based on its ability to cause analgesia, thus acting as antiinflammatory, useful in various pathological states associated with inflammation. This study aims to isolate and characterize cell wall polysaccharides of four different yeasts: R. mucilaginous (CCMB 33d1), Aureobasidium pullulans (CCMB 324), Pseudozyma sp. (CCMB 306), Trichosporonoides sp. (CCMB 298) and study their biotechnological applications, regarding the ability to suppress inflammation "in vivo". The yeasts were obtained from the Culture Collection of Microorganisms of Bahia located in the Universidade Estadual de Feira de Santana. The best conditions of pH, temperature and/or extraction time was studied, applying Response Surface Methodology. Polysaccharides extracted from the four fungal sources have been subjected to structural analysis by Infra Red (FT-IR) and Nuclear Magnetic Resonance (NMR) Spectroscopy and High Performance Liquid Chromatography (HPLC). After analysis of the spectra obtained by FT-IR and NMR associated with the result obtained from monomeric composition by HPLC, after acidic hydrolysis, the samples can be identified as mixtures of β-D-glucans and α-D-mannans for Aureobasidium pullulans (CCMB 324), Pseudozyma sp. (CCMB 306), and the majority of D-glucan composition for the cell wall polysaccharides extracted from Trichosporonoides sp. (CCMB 298) and R. mucilaginous (CCMB 33d1). The tests "in vivo" the analgesic activity showed that cell wall polysaccharides extracted from yeast isolated from the semi-arid Northeast were able to cause analgesia, probably by inhibiting the production of inflammatory mediators, except Trichosporonoides sp. Because the tests this last was not performed. Thus, the semi-arid Northeast proved to be a promising source of microorganisms with potential to produce new biomolecules capable of acting as a source of potential drugs.