A bioprocess for the production of phytase from Schizophyllum commune: studies of its optimization, profile of fermentation parameters, characterization and stability.

Schizophyllum commune produces phytase through solid-state fermentation using different agroindustrial residues. After optimization of phytase production, a maximal level of phytase (113.7 Units/gram of dry substrate) was obtained in wheat bran based medium containing 5% sucrose, 50% humidity, 7.5% of biomass at 33 °C pH 7.0 during 72 h and a 285% improvement in enzyme titre was achieved. Analysis of fermentation parameters profile for phytase production showed the highest productivity (1.466 Units/gram of dry substrate/hour) in 66 h of fermentation. Phytase has an optimal pH of 5.0, an optimal temperature of 50 °C and K (m) and V (max) values of 0.16 mM and 1.85 µmol mL(-1) min(-1), respectively. Phytase activity was stimulated essentially in the presence of K(+), Ca(2+), Mg(2+), Mn(2+), Zn(2+), Cu(2+), Fe(2+), Fe(3+), Co(2+), Ni(2+), acetate and citrate at concentrations of 1 mM. Phytase had the best shelf life when stored at a cooling temperature, maintaining 38% of its initial activity after 112 days of storage, and still presenting enzymatic activity after 125 days of storage. Stability studies of phytase performed in aqueous enzyme extracts showed satisfactory results using polyethyleneglycol 3350, carboxymethylcellulose, methylparaben, mannitol and benzoic acid in concentrations of 0.25, 0.025, 0.025, 0.25, and 0.0025%, respectively. PEG 3350 was shown to be the best stabilizing agent, resulting in 109% of phytase activity from the initial crude extract remaining activity in after 90 days.

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.

Analysis of inducers of xylanase and cellulase activities production by Ganoderma applanatum LPB MR-56.

This manuscript describes the analysis of the effect of cellulose, carboxymethylcellulose (CMC), xylan, and xylose as inducers of cellulase and xylanase activity production by Ganoderma applanatum MR-56 and the optimization of their production in liquid cultures by statistical methods. The Plackett-Burman screening design was applied to identify the most significant inducers of xylanase and cellulase activities production by G. applanatum MR-56. The most significant effect on xylanase and cellulase activities production was exercised by cellulose, even if xylose and CMC were also effective at some times. The combined effect of cellulose, yeast extract, and pH was analyzed by a 2(3) factorial experimental design with four central points that showed that the maximum tested cellulose (1 % w/v) and yeast extract (5 g L(-1)) concentrations gave the maximum production of xylanase (8.24 U mL(-1)) and cellulase (3.29 U mL(-1)) activity at pH 6 and 4, respectively. These values achieved for cellulase and xylanase activity represent 12-25 fold and 36 fold higher values than the maximum so far reported for other strains of G. applanatum, respectively.