Determinación de la velocidad máxima de transferencia de oxígeno y la velocidad específica máxima de consumo de oxígeno en cultivos por lote de la bacteria (Bacillus subtilis DS23) en un biorreactor

Abstract

This research was carried out with the purpose of optimizing the production of biosurfactant with amphipathic activity from Bacillus subtilis DS23, which has been characterized as one of the microorganisms that have the best performance when producing this type of compounds. The experimentation was carried out in a 5-liter bioreactor maintaining constant parameters such as pH at 6.5, temperature at 30 Celsius degrees and aeration in 1 volume of air per volume of medium per minute (vvm), working with speeds of agitation of 150, 200 and 300 revolutions per minute (rpm) being this the only parameter that was varied. It was shown that the production of biomass and bio-surfactant in a stirred tank bioreactor is strongly influenced by agitation. The best results of both biomass and biosurfactant were obtained at 300 rpm, agitation speed that was used to determine the parameters proposed in this investigation. Using the Humphrey dynamic method using air as an oxygen-carrying gas, the effect of dissolved oxygen in the medium on the growth and production of biosurfactant was assessed by estimating the volumetric oxygen transfer coefficient (KLa), the specific rate of oxygen consumption (qO2) and the oxygen transfer rate (VTO) obtaining 0.002 h-1, 0.079 mmol O2 for L * h and 0.312 h-1 respectively. It was decided to evaluate these parameters because they are key in aerobic crops, and they are intended to serve as scaling criteria in future research.