A model of plant residues utilization for selenium enriched yeast production under submerged fermentation

Abstract

Selenium is an essential micronutrient in animal and human health. In animals it improves reproductive performance, meat, milk and egg quality and it reduces mortality rate. Yeast incorporates selenium directly to its aminoacids and they are able to grow in different kinds of substrates. The use of plant biomass in fermentative process it's a cheaper alternative rather than synthetically growth media because it uses agroindustrial residues to produce more valuable substrates. The mainly goal of this study is to produce selenium enriched yeast using agroindustrial residues for application in animal feeding. Tests will be made using different hydrolysates, that will be obtained from acid hydrolysis of rice, corn and soy bran and also sugar cane bagasse in which 15.0 mg/L of selenium as sodium selenite will be added in order to evaluate cell growth, cell viability and selenium uptake. After the selection of the hydrolysate, a fractionated5-1 factorial study will be designed with three central points to evaluate the influence of the growth media in biomass production and selenium uptake. It will be used for the tests a shake flask under 30pC, 200 rpm for 72h collecting periodic samples to keep up with the fermentative process. In the end of the growth phase the cells will be digested using HNO3 for spectrometry selenium analysis. The formation of secondary products such as ethanol and glycerol will be analyzed by High Performance Liquid Chromatography (HPLC) while sugar, proteins and phenolic compounds by spectrometry. This study contributes for a valuable use of agroinduatrial residues in economical and social important byproducts.