2-Phenylethanol (2-PE) is an alcohol that emits an aroma of the fresh and delicate roses. Natural 2-PE is present in many plants, especially in the rose oil. Because of its delicate aroma and sweet taste, 2-PE is the second-most commonly used flavor after vanillin. 2-PE and its high valued derivatives can be used in food, tobacco, and cosmetics industries. The global annual output of 2-PE is nearly 10,000 tons in 2010. Chemical synthesis is the basic method used to produce 2-PE. However, benzene or styrene—the raw materials used to synthesize 2-PE—are regulated chemicals. Methods to produce natural 2322-PE include plant extraction and microbial transformation. The production of 2-PE through biotransformation presents broad application prospects. Several microorganisms can produce 2-PE. However, yeasts with generally recognized as safe (GRAS) designation Kluyveromyces marxianus and Saccharomyces cerevisiae stand out among them. The drawback of the biocatalytic process is the inhibition of yeast growth by the accumulating product. To overcome this challenging limitation, production strategies have been developed, including identification of highly productive microorganism, biocompatible in situ product removal techniques (ISPR), use of industrial wastes as substrates, and more recently, genetic modification of microorganisms.

Polymers and specifically hybrid polymeric membranes have been identified as effective formulations in adsorption processes. Nevertheless, the adsorption mechanisms associated with their thermodynamics and kinetics are not fully understood, particularly when these polymeric membranes are used to adsorb 2-Phenylethanol (2-PE) to intensify its production in a specific bioconversion process. This work was aimed at giving phenomenological insights on the adsorption of 2-PE on a set of novel porous hybrid membranes based on polyurethane and keratin biofiber obtained from chicken feathers. Feathers, considered as a waste by-product of the poultry industry, represent an alternative source of keratin, a biopolymer that can be used to design low-cost materials from natural resources. Two types of hybrid membranes were prepared. i. e. composite and copolymer. Firstly, these materials were characterized by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) (before and after the adsorption process) and X-Ray (WAXD) analysis. Secondly, these materials, including the reference ones (keratin biofiber and polyurethane), were evaluated during the removal of 2-PE, relating their adsorption capabilities to physiochemical properties elucidated during the characterization. Particularly a composite with 0.1 g of chicken-feather-keratin (C1) presented the highest removal percentage (60.68%), a significant initial adsorption rate (0.2340 mg _PE .h ⁻¹ .g _A ⁻¹ ), the maximum adsorption capacity (12.13 mg _PE .g _A ⁻¹ ) and the best stability and mechanical properties at studied operating conditions. In comparison with results reported in literature, in this composite carbonyl functional groups from polyurethane showed rather major affinity to 2-PE than amino groups from the keratin biofiber. To this end, parameters associated with its industrial application were obtained, namely thermodynamic and kinetic information was obtained from a proper design of experiments and phenomenological models based on adsorption macroscopic fundamentals.

Las bacterias ácido-lácticas (BAL) son microorganismos de gran importancia para la industria de alimentos y para la salud. Inicialmente estos microorganismos se utilizaron principalmente para conservar alimentos, sin embargo, a través de los años se ha estudiado su potencial actividad biológica y la producción de compuestos con potencial bioactivo, como el caso de los exopolisacáridos (EPS). Los EPS son polisacáridos presentes fuera de la pared celular microbiana con una composición heterogénea basada principalmente en carbohidratos y una matriz proteica. Son sintetizados por diversos microorganismos como el caso de las microalgas, bacterias, hongos y levaduras, como una respuesta al estrés ambiental. En alimentos los EPS se emplean como agentes de viscosidad, estabilizadores, emulsionantes, gelificantes, entre otros. Por otro lado, algunos EPS han mostrado propiedades inmunomoduladoras, reducción de colesterol, anticancerígenas, anticoagulantes e interfieren con el crecimiento de patógenos, por lo que son de gran interés para el área de salud.