RESUMEN
The sustainable production of fine/bulk chemicals is often hampered by product toxicity and inhibition to the producing micro-organisms. Consequently, the product must be removed from the micro-organisms' environment. To achieve this, so-called solvent-impregnated resins (SIRs) as well as commercial resins have been added to a Pseudomonas putida S12TPL fermentation that produces phenol as a model compound from glucose. The SIRs contained an ionic liquid which extracts phenol effectively. It was observed that the addition of these particles resulted in an increased phenol production of more than a fourfold while the commercial resin (XAD-4) which is widely used in aromatic removal from aqueous phases, only gave a 2.5-fold increase in volumetric production.
Asunto(s)
Fermentación , Microbiología Industrial/métodos , Fenol/metabolismo , Pseudomonas putida/crecimiento & desarrollo , Pseudomonas putida/metabolismo , Resinas Sintéticas/química , 1-Octanol/química , Adsorción , Glucosa/metabolismo , Fenol/química , Fenol/aislamiento & purificación , Ácidos Fosfínicos/química , Poliestirenos/química , Polivinilos/química , Solventes/químicaRESUMEN
This paper evaluates frontal analysis for routine sugar isotherm measurements at industrial conditions, that is concentrations up to 400 kg/m3 and a temperature of 60 degrees C. Sugar isotherms for a gel type cation-exchange resin loaded with metal ions were measured in a HPLC setup equipped with a UV detector. It is shown experimentally that isotherms obtained with large concentration steps (step series method) underestimated the isotherm. The underestimation is larger for larger resin particle size. In contrast, isotherms obtained with small concentration steps (staircase method) yielded correct isotherms. The seldom-mentioned change of the sorbent volume during the course of an isotherm measurement is discussed. It is shown that shrinking of 4% cross-linked resin at high sugar concentration has a negligible effect on the isotherm. Furthermore, the isotherms obtained with staircase frontal analysis agreed very well with those obtained with the independent, though more laborious and time-consuming, adsorption-desorption method. Staircase frontal analysis is shown to be convenient and accurate and is therefore recommended for isotherm measurements covering large concentration ranges.
