ABSTRACT The robustness of the simulation of bioethanol concentration from sugarcane faces two major challenges: the presence of several minor components and the nonlinear behavior of vapor-liquid equilibrium (VLE) calculations. This work assesses the effect of simplifications to overcome these difficulties. From a set of seventeen substances, methanol, n-propanol, isobutanol, 2-methyl-1-butanol and 3-methyl-1-butanol were selected through the examination of the influence of each minor component on vapor-liquid equilibrium calculations of ethanol-water-third component systems. The selection procedure was based on Txy diagrams built using the modified Raoult's law. The influence of the ratio between the vapor phase fugacity coefficients and of the Poynting correction factor were verified. The accuracy of four correlations for vapor pressure was evaluated, and two functional-group activity coefficient models were scrutinized: the recent Functional-Segment Activity Coefficient (F-SAC) and the UNIFAC-Do model.

Genetically attenuated microorganisms, pathogens, and some commensal bacteria can be engineered to deliver recombinant heterologous antigens to stimulate the host immune system, while still offering good levels of safety. A key feature of these live vectors is their capacity to stimulate mucosal as well as humoral and/or cellular systemic immunity. This enables the use of different forms of vaccination to prevent pathogen colonization of mucosal tissues, the front door for many infectious agents. Furthermore, delivery of DNA vaccines and immune system stimulatory molecules, such as cytokines, can be achieved using these special carriers, whose adjuvant properties and, sometimes, invasive capacities enhance the immune response. More recently, the unique features and versatility of these vectors have also been exploited to develop anti-cancer vaccines, where tumor-associated antigens, cytokines, and DNA or RNA molecules are delivered. Different strategies and genetic tools are constantly being developed, increasing the antigenic potential of agents delivered by these systems, opening fresh perspectives for the deployment of vehicles for new purposes. Here we summarize the main characteristics of the different types of live bacterial vectors and discuss new applications of these delivery systems in the field of vaccinology.

Bacillus megaterium is a promising host for expression of heterologous proteins. This paper reports the nutrient consumption patterns and production of metabolites for three different strains of B. megaterium, ATCC 14945, QMB 1551 and PV 361, which is QMB 1551 with seven constitutive plasmids deleted. 14 h cultivations in agitated flasks were run, for two different media: A (LB plus 10g/L glucose) and B (medium A, with the yeast extract replaced by tryptone). Strains PV361 and QMB 1551 showed higher maximum specific growth rates in medium B, reaching 0.42 h-1 and 0.48 h-1 respectively. The main by-products of the glucose overflow mechanism were acetate and lactate, for all three strains, which had preferential amino acids for substrate: Ala, Asp, Glu, Ser. No production of alcohols was detected.

A síntese enzimática de ampicilina oferece menor impacto ambiental em relação ao processo utilizado atualmente pela indústria farmacêutica. Mas seu rendimento e produtividade devem ser melhorados para tornar essa rota competitiva. Alguns estudos empíricos para otimizar a rota enzimática de síntese de antibióticos beta-lactâmicos vêm sendo realizados. Entretanto, a utilização sistemática de métodos matemáticos de otimização nesse processo não é encontrada na literatura. Neste trabalho, utilizaram-se técnicas de controle ótimo para otimizar a alimentação de reagentes na síntese enzimática de ampicilina em reator operando em batelada alimentada. Resultados simulados mostram que, em reator integrado (com precipitação dos produtos) operado em batelada alimentada, conversões de 6-APA e rendimento de EMFG de 88% a 92% são factíveis, assim como produtividades entre 3,5 e 5,5 mM.min-1.

In this work, optimal control techniques were used to optimize the feed of reactants during the enzymatic synthesis of ampicillin in a semi-batch reactor. Simulation results showed that a semi-batch integrated reactor (with product crystallization) might achieve 88% 6-APA (6-aminepenicillanic acid) conversion and 92% of PGME (phenylglycine methyl ester) yield, with a productivity between 3.5 and 5.5 mM min-1.

A hidrólise parcial de proteínas do soro de queijo, realizada por enzimas imobilizadas em suporte inerte, pode alterar ou evidenciar propriedades funcionais dos polipeptídeos produzidos, aumentando assim suas aplicações. O controle do pH do reator de proteólise é de fundamental importância para modular a distribuição de pesos moleculares dos peptídeos formados. Os sinais de pH e temperatura utilizados pelo algoritmo de controle e inferência de estado podem estar sujeitos a ruído considerável, tornando importante sua filtragem. Apresentam-se aqui resultados da implementação, no sistema de monitoramento do processo, de algoritmo suavizador, que utiliza mínimos quadrados com penalização para o pós-tratamento dos dados. Compara-se ainda o desempenho de diferentes algoritmos na filtragem em tempo real dos sinais utilizados pelo sistema de controle, a saber: redes neurais artificiais, média móvel e o sobredito suavizador.

This work presented the results of the implementation of an off-line smoothing algorithm in the monitoring system, for the partial hydrolysis of cheese whey proteins using enzymes, which used penalized least squares. Different algorithms for on-line signals filtering used by the control were also compared: artificial neural networks, moving average and smoothing algorithm.