1,3-Propanediol production from glycerol with a novel biocatalyst Shimwellia blattae ATCC 33430: Operational conditions and kinetics in batch cultivations

Shimwellia blattae ATCC 33430 as biocatalyst in the conversion of 1,3-propanediol from glycerol is herein evaluated. Several operational conditions in batch cultivations, employing pure and raw glycerol as sole carbon source, were studied. Temperature was studied at shaken bottle scale, while pH control strategy, together with the influence of raw glycerol and its impurities during fermentation were studied employing a 2 L STBR. Thereafter, fluid dynamic conditions were considered by changing the stirring speed and the gas supply (air or nitrogen) in the same scale-up experiments. The best results were obtained at a termperature of 37ºC, an agitation rate of 200 rpm, with free pH evolution from 6.9 and subsequent control at 6.5 and no gas supply during the fermentation, employing an initial concentration of 30 g/L of raw glycerol. Under these conditions, the biocatalyst is competitive, leading to results in line with other previous works in the literature in batch conditions, reaching a final concentration of 1,3-propanediol of 13.84 g/L, with a yield of 0.45 g/g and a productivity of 1.19 g/(L·h) from raw glycerol

Study of the enzymatic activity inhibition on the saccharification of acid pretreated corn stover

The inhibition of the enzymatic saccharification of acid pretreated corn stover (PCS) biomass due to several compounds either present in PCS or produced during saccharification has been studied. The prospective inhibitors tested were glucose ( 110 g L1 ), celobiose ( 24 g L1 ), xylose ( 50 g L1 ), arabinose ( 1.5 g L1 ), furfural ( 2gL1 ), hydroxymethylfurfural ( 1gL1 ), acetic acid ( 4gL1 ), and lignin ( 50 g L1 ). Each of these compounds was added at three different concentrations, being the concentration intervals different according to standard maximum concentrations of such compounds in the reaction medium, previously measured and described in literature. In addition, these experiments were employed to evaluate the standard error present during the evaluation of the results obtained in the inhibition reactions. Those results show that significant inhibition was only detected for lignin (more than 25 g L1 ) and it was also appreciable for glucose at high concentrations (above 75 g L1 ), although it was not remarkable at medium concentrations (40 g L1 ). On the other hand, neither of the remaining compounds tested presented any significant inhibitory effect at the usual process concentration range

Modeling the Succinic Acid Bioprocess: A Review

Succinic acid has attracted much interest as a key platform chemical that can be obtained in high titers from biomass through sustainable fermentation processes, thus boosting the bioeconomy as a critical production strategy for the future. After several years of development of the production of succinic acid, many studies on lab or pilot scale production have been reported. The relevant experimental data reveal underlying physical and chemical dynamic phenomena. To take advantage of this vast, but disperse, kinetic information, a number of mathematical kinetic models of the unstructured non-segregated type have been proposed in the first place. These relatively simple models feature critical aspects of interest for the design, control, optimization and operation of this key bioprocess. This review includes a detailed description of the phenomena involved in the bioprocesses and how they reflect on the most important and recent models based on macroscopic and metabolic chemical kinetics, and in some cases even coupling mass transport.Depto. de Ingeniería Química y de MaterialesFac. de Ciencias QuímicasTRUEpu

Desarrollo de recursos didácticos adaptados para la Generación Z en el ámbito de la Ingeniería Química

En este Proyecto Innova-docencia se van a elaborar una serie de recursos didácticos que sirvan de apoyo a la docencia presencial y virtual de asignaturas del área de la Ingeniería Química a nivel de Grado y de Máster enfocados a la Generación Z

Hidrólisis enzimática de materiales lignocelulósicos

El desarrollo de la biorrefinería como modelo de producción análogo a las refinerías se ha visto favorecido tanto por las políticas ambientales adoptadas por los distintos organismos, tanto nacionales como plurinacionales, como por la previsible escasez futura de los combustibles fósiles y de las materias primas no renovables. La biorrefinería se define en la actualidad como la forma de producción basada en la biomasa que persigue obtener tanto productos químicos, finales o intermedios, como energía y alimentos a través de procesos ambientalmente sostenibles.Existen diversos tipos de biorrefinerías, tanto en función de los procesos que llevan a cabo, y los productos que ponen en el mercado, como del tipo de biomasa que emplean como materia prima. Dentro de las biorrefinerías que se están desarrollando en la actualidad, destacan aquellas que emplean biomasa lignocelulósica como materia prima. Esta biomasa se compone, fundamentalmente, de celulosa, hemicelulosa y lignina. Asimismo, cada uno de estos polímeros naturales puede ser procesado y separado en sus componentes fundamentales, que se pueden emplear como materias primas o productos intermedios en otros procesos.

Modeling the Succinic Acid Bioprocess: A Review

Succinic acid has attracted much interest as a key platform chemical that can be obtained in high titers from biomass through sustainable fermentation processes, thus boosting the bioeconomy as a critical production strategy for the future. After several years of development of the production of succinic acid, many studies on lab or pilot scale production have been reported. The relevant experimental data reveal underlying physical and chemical dynamic phenomena. To take advantage of this vast, but disperse, kinetic information, a number of mathematical kinetic models of the unstructured non-segregated type have been proposed in the first place. These relatively simple models feature critical aspects of interest for the design, control, optimization and operation of this key bioprocess. This review includes a detailed description of the phenomena involved in the bioprocesses and how they reflect on the most important and recent models based on macroscopic and metabolic chemical kinetics, and in some cases even coupling mass transport

Kinetic Modeling of Dihydroxyacetone Production from Glycerol by Gluconobacter oxydans ATCC 621 Resting Cells: Effect of Fluid Dynamics Conditions

Dihydroxyacetone production from glycerol has been studied. Cultures of Gluconobacter oxydans ATCC 621, a promising microorganism that is able to convert glycerol into dihydroxyacetone, has been employed. In this work, the influence of oxygen transport rate and the fluid dynamic conditions have been studied working with resting cells cultures. Several experiments were carried out at two different scales: 250 mL Erlenmeyer flasks and a 2 L stirred tank bioreactor, varying the agitation speed. Product and substrate concentration were determined employing high-performance liquid chromatography. Additionally, oxygen concentration was measured in the runs carried out in stirred tank reactors. Taking into account the results obtained in these experiments, three different behaviors were observed, depending on the mass transfer and chemical reactions rates. For experiments with low stirring speed (below 200 rpm for shake flasks and 300 rpm for reactors), the oxygen transport rate is the controlling step, while at high stirring speed (over 300 rpm in shake flasks and 560 rpm in the bioreactor), the chemical reaction is controlling the overall process rate. In some runs conducted at medium agitation, a mix control was found. All the kinetic models were able to reproduce experimental data and fulfill thermodynamic and statistical criteria, highlighting the importance of the mass transfer rate upon this system

1,3-Propanediol production by Klebsiella oxytoca NRRL-B199 from glycerol. Medium composition and operational conditions

Production of 1,3-propanediol from glycerol using Klebsiella oxytoca NRRL-B199 has been studied. Medium composition has been optimized by means of a statistical design based on the Taguchi method. Strong influences of glycerol and phosphate concentrations have been detected on biomass and product yields. Other factors, such as magnesium concentration and K:Na ratio, have shown a small influence on both responses, biomass and product concentrations. An optimized medium composition has been proposed, leading to a final 1,3-propanediol concentration of 12.4 g/L with a selectivity of 72% with respect to glycerol consumed at shaken bottle-scale. Once the medium composition had been optimized, the scale-up from shaken bottles to STBR was conducted. Several experiments in a 2 L STBR have been conducted in order to determine the best operating conditions concerning temperature and agitation. Under the best operating conditions, i.e., a programmed variable stirring rate ranging from 50 to 100 rpm and a temperature of 37 �C, a final concentration of 13.5 g/L of 1,3-propanediol with a selectivity of 86% with respect to the glycerol consumed was obtained

Multi-feedstock lignocellulosic biorefineries based on biological processes: An overview

26 Pág.  Instituto de Ciencias Forestales (ICIFOR)The evolution of lignocellulosic biorefineries increasing the process complexity and integration through the processing of multiple raw biomass-based materials into several products is described. This critical overview deals with available lignocellulosic feedstocks, pretreatment operations, enzymatic saccharification to monosaccharides and their final transformation into bioethanol and other bio-based products. Aspects as process operating conditions, modes of operation, underlying physical and chemical phenomena, and mathematical modelling are addressed. Pretreatment stage is a key step for any further processing, specially when using multifeedstock. The use of ethanol-water mixtures for biomass fractionation is a promising treatment able to compete with the nowadays more employed pretreatment such as steam explotion and diluted acid processes. Enzymatic saccharification of pretreated biomass has been analysed considering its complexity and selectivity. Its mathematical modelling is described in detail, together with the underlying phenomena, highlighting the importance of mass transfer in a biphasic system. An adequate operation unit design, scale-up and control, and process design and integration can be ensured in this way. Finally, biotransformations of monosaccharides to biofuels and platform chemicals is analysed as they are becoming key processes within bioeconomy, in the framework of integrated biorefinery to fuels, chemicals and materials.The authors acknowledge the support of the Science and Innovation Ministry , which funded this work through Projects CTQ2017-84963-C2 (R-1 and R-2) and PCI2018-093114, and Madrid Regional Government for funding via Project RETOPROSOST P2013-MAE2907. We also thanks to CONICYT – Doctorado Becas Chile/2015- 72160108, for funding PV post-doctoral grant. This work has also been facilited by the network RESALVALOR supported by CYTED with ref. 319RT0575.Peer reviewe