Modelagem e simulação da produção de lipídios pela levedura rhodotorula mucilaginosa.

Abstract

This study aimed to model and simulate the lipid production process using Rhodotorulamucilaginosa yeast. The production from the liquid fraction remaining from the processing of the roots (popularly known as manipueira) of cassava (Manihot esculenta Crantz) was considered.The simulations were performed through a central composite design (22), and the independent variables were the initial cell (X0) and substrate (S0) concentrations for 120 hours. The fourth order Runge-Kutta method was also used to solve the differential equations during the simulation of the initial process conditions in order to evaluate the effects on dependent variables, cell (PX) and lipid (PL) productivity. For all testable conditions an increase in initial substrate concentration (S0) stimulated cell growth (PX) and lipid productivity (PL). The yield in biomass ranged from 0.012 to 0.083 g/L.h and in lipids ranged from 0.90 to 6.34 mg/L.h. Within the testable conditions under which the tests were performed, test 4 showed the highest yields, and the conditions of test 7, were the ones that provided the lowest productivity. Therefore, the concentration of 2.00 g/L cells and 40.00 g/L substrate is the most suitable condition for biomass and lipid generation. Thus, from the results obtained in the simulation, it was found that the manipueira tree proved to be a good substrate for the growth of Rhodotorulamucilaginosa yeast and for lipid production.