Bioremediation and biomass production from the cultivation of probiotic Saccharomyces boulardii in parboiled rice effluent.

The parboilization of rice generates 2 L of effluent per kilogram of processed grain. Several methodologies have previously been tested with the aim of reducing the environmental impact of this effluent. The objective of this study was to evaluate the bioremediation of parboiled rice effluent supplemented with sucrose or residual glycerol from the biodiesel during the cultivation of the Saccharomyces boulardii probiotic. In the first stage of the experiment, cultures were grown in orbital shaker, and five media compositions were evaluated: 1) parboiled rice effluent; 2) effluent supplemented with 1% sucrose; 3) effluent supplemented with 3% sucrose; 4) effluent supplemented with 15 g.L-1 of biodiesel glycerol and 5) standard yeast culture medium (YM). The addition of 1% of sucrose generated the most promising results in terms of cell viability, removal of nitrogen, phosphorus and chemical oxygen demand (COD). From these results, four independent cultures were grown in a bioreactor using effluent +1% of sucrose as the medium. This assays generated a mean of 3.8 g.L-1 of biomass, 1.8 × 1011 CFU.L-1, and removal of 74% of COD and 78% of phosphorus. Therefore, the cultivation of Saccharomyces boulardii in parboiled rice effluent supplemented with 1% sucrose may represent a viable method by which the environmental impact of this effluent can be reduced while simultaneously producing probiotic culture for use in animal production.

Effects of chitosan-coated lipid-core nanocapsules on bovine sperm cells.

Toxicology studies have a pivotal role for selection of new nanosystems. As lipid-core nanocapsules (LNC) rise as a potential system not only for drug delivery but also for immunotherapy and gene therapy, the demand for models of toxic screening increases, and sperm arises as a promising model due to the easiness to evaluate its viability parameters. LNCs were coated with chitosan, chitosan-coated lipid-core nanocapsules (LNC-CS), in order to modify the nanocapsule surface. We evaluated the toxicity of LNC and LNC-CS after incubation with bovine sperm in different concentrations (2.5%, 5%, 10%, 20%, 40% and 80%) (v/v) and periods of exposure (0h and 1h). CASA parameters and flow cytometry assays were performed to assess LNC and LNC-CS effects. The results corroborated with previous studies indicating that there is no toxicity from LNCs and LNC-CS below 40% (v/v) concentration.