Selenium-Enriched Probiotic Saccharomyces boulardii CCT 4308 Biomass Production Using Low-Cost Sugarcane Molasses Medium

Abstract

Food supplements have been increasingly investigated. Probiotics have several benefits for human and animal health and selenium (Se) is widely recommended against oxidative stress. In this context, the aim of this study was to develop a low-cost bioprocess to produce a functional food product comprising both probiotic and Se accumulation. Yeast cells of Saccharomyces boulardii CCT 4308 were cultivated using sugarcane molasses as substrate. Optimization studies were performed to evaluate the best medium composition for biomass production and Se-accumulation in batch and fed-batch systems. Optimized conditions were defined with a medium composed of 150 g L -1 sugarcane molasses and 12 g L -1 yeast extract, with feeding of 100 g L -1 sugarcane molasses and 100 μg mL -1 of Se incorporation after 4 h and 10 h of fermentation, respectively, during 48 h in STR (stirred tank reactor). Best biomass production reached 14.52 g L -1 with 3.20 mg Se g -1 biomass at 12 h. Process optimization led to 4.82-fold increase in biomass production compared to initial condition. A final Se-enriched S. boulardii CCT 4308 biomass was obtained, which is comparable to commercial products. An alternative probiotic yeast biomass was efficiently produced as a new food-form of Se supplement in a sustainable process using an inexpensive agro-industrial residue.

Mineral-Enriched Postbiotics: A New Perspective for Microbial Therapy to Prevent and Treat Gut Dysbiosis

“…In this condition, two Lactobacillus paracasei strains (ML13 and CH135) were able to bioaccumulate approximately 40 mg Se/g biomass. Optimization studies to produce Se-enriched Saccharomyces boulardii CCT 4308 probiotic biomass in a batch system noted that the best Se accumulation was observed at 100 μg/mL while the strain can tolerate 400 μg/mL, and a good strategy to avoid a metal toxic effect is the addition of selenium at the end of the logarithmic phase [ 53 ]. In this case, the best biomass production (14.52 g/L) was obtained after 12 h cultivation, and cells accumulated 3.2 mg Se/g biomass, a result comparable with the selenium bioaccumulation by some commercial probiotics.…”

“…In this case, the best biomass production (14.52 g/L) was obtained after 12 h cultivation, and cells accumulated 3.2 mg Se/g biomass, a result comparable with the selenium bioaccumulation by some commercial probiotics. Natural mediums were used to grow Se-enriched yeasts, sugar molasses—a complex carbon source with small amounts of proteins, vitamins, and nitrogen compounds in the case of S. boulardii —and juices from germinated brown rice, beewort, and soybean sprouts in a ratio of 4:4:2 for S. cerevisiae , where different concentrations of sodium selenite were added [ 53 , 54 ]. S. cerevisiae grew with lower amounts of inorganic selenium (15 μg/mL Na 2 SeO 3 ) but produced 8.5 g/L biomass, and total Se achieved 3.53 mg/L.…”