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Desenvolvimento e distribuição de espécies de macrófitas aquáticas em áreas alagadas da represa do Lobo-Broa (UHE Carlos Botelho) em função do estado trófico
(Universidade Federal de São Carlos, 2011-12-22) Medeiros, Guilherme Ruas; Tundisi, José Galizia; https://lattes.cnpq.br/5730659239785432; https://lattes.cnpq.br/9794950718150922
A comunidade de macrófitas aquáticas se constitui como importante componente em ecossistemas lênticos e lóticos, habitando áreas permanentemente alagadas ou sujeitas a inundações. Desta forma o presente estudo caracterizou as áreas alagadas e as possíveis diferenças nas características físicas e químicas dos sedimentos e da água circundante aos estandes das espécies de macrófitas Eichhornia crassipes, Salvinia auriculata e Mayaca fluviatilis ocorrentes no reservatório do Broa em distintos tributários. Estes vegetais possuem importante papel como fonte de matéria orgânica e dos nutrientes fósforo e nitrogênio contribuindo para uma maior estocagem dos mesmos. A qualidade das amostras de água circundante aos estandes foram influenciadas principalmente pela ação dos ventos ocorridas na amostragem do período seco (agosto de 2010), que contribuíram para o revolvimento da coluna d`água agindo diretamente sobre os estandes. A avaliação do estado trófico do reservatório verificou que os ambientes estudados apresentam diferenças nas concentrações de fósforo na água, onde foi possível identificar uma área alagada hiper-eutrófica próximo ao rio Itaqueri e oligo-mesotrófica nas áreas alagadas formadas pelos Ribeirão do Lobo e Córrego das Perdizes. Contatouse que os teores de fósforo e nitrogênio apresentam uma distribuição desigual entre as espécies e também entre as suas estruturas, sendo as raízes responsáveis pelo armazenamento de maiores concentrações destes nutrientes. The aquatic macrophyte communities constitutes an important component in lentic and lotic ecosystems, inhabiting areas permanently flooded or subject to flooding. Thus the present study characterized the wetlands and possible differences in physical and chemical characteristics of sediments and water to the surrounding stands of macrophytes Eichhornia crassipes, Salvinia auriculata and Mayaca fluviatilis occurring in Broa reservoir in different tributaries. These plants play an important role as a source of organic matter and nutrients phosphorus and nitrogen contributing to greater storage of same. The quality of water samples from the surrounding stands were mainly influenced by the wind occurred in the sample of the dry period (August 2010), which contributed to the turning of water column acting directly on the stands. Assessing the trophic state of the reservoir found that the studied environments having different concentrations of phosphorus in the water, where it was possible to identify a hyper-eutrophic wetland near the Itaqueri river and oligomesotrophic in Ribeirão do Lobo and Cóorego das Perdizes. It was noted that the levels of phosphorus and nitrogen have an unequal distribution among species and also between their structures, the roots being responsible for the storage of higher concentrations of these nutrients
Sistema automático de supervisão e controle de cultivos de alta densidade celular de E. coli recombinante
(Universidade Federal de São Carlos, 2011-12-22) Horta, Antonio Carlos Luperni; Zangirolami, Teresa Cristina; https://lattes.cnpq.br/4546701843297248; https://lattes.cnpq.br/5923938048634505
High cell density cultivations of recombinant E. coli are a fast and economical way to produce recombinant proteins. Through this bioprocess, products with high added value and pharmaceuticals of great importance such as insulin, human and bovine growth hormone, protein antigens for formulation of vaccines, enzymes, among others, are obtained. However, keeping these cultivations within the desired conditions becomes a major challenge, since some variables such as dissolved oxygen concentration (DOC) and substrate concentration are difficult to control. Therefore, the development and implementation of an automatic monitoring and control tool are key requirements for the performance of high density cultivation. The present work has as main objectives to study feeding strategies for high cell density cultivation of recombinant Escherichia coli and develop a computational tool capable of ensuring the implementation of the chosen strategies, performing the monitoring, control and supervision of the cultivations. Fed batch cultivations were carried out under the supervision of the tool in a 5 L in-house bioreactor, equipped with sensors for temperature, dissolved oxygen, pH, pressure and biomass (sensor that measures the concentration of viable cells based on permittivity measurements), peristaltic pumps and connected to the gas analyzer. The tool was developed with LabView 8.0 and MatLab 6.5, being the acquisition and communication with the different bioreactor accessories via compact Field Point. Twenty two fed-batch cultivations with 5 different clones of E. coli, BL21(D3) expressing the enzyme penicillin G acylase (PGA) as well as antigenic proteins of S. pneumoniae (PspA3, PspA245 and PspA4Pro) and E. rhusiopathiae (SpaA) were performed during the development of the tool and the studies of feeding strategy. Both defined medium (HDF modified) as complex medium (ZYM-5052 modified), usually having glycerol as main carbon source and IPTG or lactose as inducers were used. In all cultivations, samples were collected to quantify the concentration of cells (dry weight method in filter of 0.22 m and optical density at 600 nm), organic acids, glucose, glycerol and lactose (HPLC) as well as protein expression (densitometry and NIPAB method for PGA) and plasmid stability (plating). The tool SUPERSYS_HCDCR (registered as a free software) developed, implemented and validated in the performed cultivations, carries out the basic functions of bioreactor supervision software, such as monitoring and data acquisition of pressure, temperature, pH, DOC, fraction of CO2 and O2 in the outlet gas as well as real-time estimate of the respiratory quotient, the rate of oxygen consumption and CO2 production. However, it also has the following special features, including: i) automatic control of air and oxygen flow according to cellular demand, ii) automatic activation of the feed pump at the end of the batch; iii) automatic control of feeding flow rate as function of the specific growth rate inferred in real time; iv) automatic control of feeding flow rate constrained by the concentration of dissolved oxygen, v) audible alarms indicating failures in the process; vi) failure messages sent via email; vii) automatic control of dissolved oxygen concentration; viii) control of the bioreactor pressure; and ix) control of bath temperature. Regarding the studies of feeding strategies aimed at biomass productivity increase in high cell density cultivations of recombinant E. coli, using the supervision tool developed together with changes in the composition of the synthetic culture medium available in the literature, a cellular concentrations greater than 150 g/L was achieved in less than 24 hours of cultivation, corresponding to a productivity of 9.2 g/Lh. This value, which is higher than the reported in the literature, was obtained without acetate accumulation and allowing high production of recombinant protein.
Estudos preliminares de produção de ácido glucônico a partir de sacarose invertida em biorreator airlift
(Universidade Federal de São Carlos, 2011-12-22) Lopes, Sidney Magalhães; Badino Júnior, Alberto Colli; https://lattes.cnpq.br/4796007900701417
The use of sucrose for the production of industrial inputs with higher added value has a great industrial interest, especially glucose and fructose which present many advantages over sucrose in industrial processes. Gluconic acid and its derived salts can be mentioned as second generation products also having wide industrial applicability. This study aimed to perform a preliminary evaluation of the enzymatic process for simultaneous production of gluconic acid and, consequently, its derived salts and a high-fructose syrup from sucrose inverted using glucose oxidase (GOD) enzyme in a concentric draft tube airlift bioreactor with 2.0 working volume. For this propose, the volumetric oxygen transfer coefficient (kLa), obtained under different aeration conditions using solutions with different inverted sucrose concentrations, was firstly evaluated. The results led to a correlation to estimate kLa during the oxidation of glucose to gluconic acid in an airlift bioreactor as a function of air flow rate and medium viscosity. Experimental trials were carried out in batch at 35 °C and pH 5.5 in order to produce gluconic acid with different initial glucose concentrations (20 and 40 g.L-1) in the presence or absence of fructose, and with two different enzyme concentrations. The consumption of glucose and dissolved oxygen was monitored throughout the trials. The kinetic parameters for the process (Vmax, KS and KO) were obtained by fitting of the kinetic model to the experimental values. The results showed that the presence of fructose did not significantly affect the affinity of GOD for glucose due to the small variation of KS, as well as it did not alter Vmax values for equal concentrations of KO showed that, although the dissolved O2 concentration was small compared to that of glucose in the medium, the oxygen was not the limiting factor of the process. The results, even though preliminary, demonstrate the viability of developing a simultaneous production process for gluconic acid and highfructose syrup from inverted sucrose.