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The species of the genus Pleurotus produce large amounts of biomass and exopolysaccharide (EPS) in submerged cultures, which may be used for biotechnological purposes. In the present work two Brazilian autochthonous strains of edible Pleurotus (P. ostratoroseus Sing. and P. ostreatus "florida") were used. The fungi grown in liquid Potato Dextrose medium (PD) were used as inocula to cultivate those microorganisms in the POL culture medium. After a 9-day incubation, the optimal growth time for biomass production, P. ostreatus "florida" presented higher biomass production (22.8 g d.w./l) than P. ostreatoroseus (16.8 g d.w./l). After a 7-day incubation, the optimal growth time for EPS production, P. ostreatoroseus produced higher amounts of crude EPS (5.8 g d.w./l) than P. ostreatus "florida" (1.4 g d.w./l). Relative carbohydrate composition for P. ostreatoroseus and P. ostreatus "florida" EPS were: glucose (95.5-87.7), galactose (traces - 4.9), mannose (traces - 3.1), xylose (1.3-2.5), and arabinose (3.2-1.8). Lower ammonium sulfate concentration in the POL culture medium increased the exopolysaccharides production by P. ostreatoroseus.

The aim of this study was to evaluate in fibroblast cultures the direct cytotoxic effects of etch-and-rinse, self-etch, and universal adhesive systems. The sterile glass cover slips (n = 3) were then immersed in culture medium to obtain the eluates for the experimental groups: (1) Adper™ Single Bond 2; (2) Ambar; (3) Adper™ Scotchbond™ Multi-Purpose; (4) Scotchbond™ Universal; (5) Ambar Universal; and (6) OptiBond All-In-One. As a negative control, sterile glass cover slips were immersed in culture medium only. After 24 h, the eluate obtained was applied on fibroblast culture. Cell viability and cell morphology were evaluated by MTT assay and SEM, respectively. Data were analyzed by Kruskal–Wallis and Mann–Whitney tests (α = 0.05). All adhesive systems except universal reduced cell viability in 3T3 cells to between 26.04% and 56.57%, and Scotchbond Universal and Ambar Universal reduced cell viability to 2.13% and 3.57%, respectively, when compared to the negative control. Cytoplasmic membrane shrinkage and cell-free areas with residual membrane fragments from dead cells were observed. In conclusion, improvements in universal adhesive system formulations and their mechanisms of action are not accompanied by increased toxicity compared with those in other systems, warranting commitment to the use of these dentin-pulp complexes.

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