info:eu-repo/semantics/article
Valorization of an Andean crop (yacon) through the production of a yeast cell-bound phytase
Fecha
2021-09Registro en:
Conde Molina, Debora Rocío; Novelli Poisson, Guido Fernando; Kronberg, Maria Florencia; Galvagno, Miguel Angel; Valorization of an Andean crop (yacon) through the production of a yeast cell-bound phytase; Elsevier Ltd; Biocatalysis and Agricultural Biotechnology; 36; 9-2021; 1-8
1878-8181
CONICET Digital
CONICET
Autor
Conde Molina, Debora Rocío
Novelli Poisson, Guido Fernando
Kronberg, Maria Florencia
Galvagno, Miguel Angel
Resumen
The suitability of the yeast Schwanniomyces (f. Debaryomyces) occidentalis to produce phytase activity on a Smallanthus sonchifolius (yacon) extract-based medium (YSM) was studied. Optimal conditions for phytase production were evaluated in YSM at 28 °C and pH 5.5, with an inoculum of 107 cells/mL, in shaken flasks, using a Box-Benkhen optimization design, and analyzed by response surface methodology. Phytase location was determined by subcellular fractioning and protoplast formation. Maximum phytase titres were obtained with 0.11% w/v yacon reducing sugar, 0.65% w/v (NH4)2SO4 and 16 h of fermentation. The maximum phytase activity attained under these conditions was over 6-fold higher than in non-optimized medium. Scaling-up in a STR-type bioreactor further increased phytase productivity by 1.5-fold. Phytase produced was associated to the cell wall fraction, and presented optimal temperature and pH range values of 75–80 °C and 4.0–5.0, respectively, retaining 80% of its activity at 80 °C for 40 min. Progressively increasing phosphorus concentration in the medium inhibited enzyme production, up to 60% with 0.1% w/v KH2PO4. Yeast biomass, phytase production and production kinetics in YSM were similar to those produced in a cane molasses-based medium. Yacon resulted in a promising alternative feed stock to produce a yeast-bound phytase potentially applicable in the feed industry as a nutritional additive.