The effect of inclusion rate of pea meal (PM), pea protein concentrate (PPC), soybean meal (SBM), soy protein concentrate (SPC), canola meal (CM) and canola protein concentrate (CPC) in salmonid diets was determined through six corresponding meta-analyses of all data available in the literature for these six feed ingredients, which was followed by weighted regression analysis. Increasing dietary inclusion levels of SBM, SPC, CM and CPC reduced specific growth rate (SGR). Regression analysis determined all of these relationships to be linear declines in SGR (P < 0.05). Inclusion levels of PM or PPC did not influence salmonid SGR (P > 0.05). These results showed that the influence plant proteins have on salmonid SGR is dependent on ingredient type and inclusion level. PM, PPC, SBM, SPC, CM an aqueous-extracted CPC and a high phytate CPC (PCPC) were analyzed for chemical nutrient (proximate, amino acid and phosphorus analysis) and antinutrient composition and total tract digestibility (two separate digestibility trials) in rainbow trout (Oncorhynchus mykiss). The digestibility of proximate chemical components and amino acids were significantly higher for the soy products than the pea products. These digestibilities were also significantly higher in protein concentrates than in plant meals. Dry matter and gross energy digestibility was higher in CPC than in CM (P < 0.05). Phosphorus digestibility was higher in CPC-fed fish than in CM-fed fish (P < 0.05), which is likely due to the fact that CPC did not contain phytic acid. Six consecutive growth studies (one trial per test ingredient) were conducted over a 361-day period to determine the effects of feeding increasing inclusion rates of PM, PPC, SBM, SPC, CM and CPC on the growth performance of rainbow trout. Diets were formulated based on the digestible nutrient content of all ingredients as determined in the previously conducted digestibility trials, to contain 0, 75, 150, 225 or 300 g/kg of each test ingredient. All diets were nutritionally equal and contained 17.6 MJ/kg digestible energy, 386.2 g/kg digestible crude protein and were balanced for digestible essential amino acids to meet or exceed the requirements of rainbow trout. Linear and quadratic analysis was conducted on the experimental data. There were no significant regressions resulting from feeding PM, SPC or CPC at 0-300 g/kg for average daily feed intake (ADFI), specific growth rate (SGR), feed conversion ratio (FCR) or protein efficiency ratio (PER). A positive relationship was associated between PPC inclusion and ADFI (P < 0.05). There was a significantly negative quadratic equation associated with the inclusion level of SBM on SGR and FCR and significantly negative linear and quadratic equations for PER. There were significantly negative linear relationships between the inclusion rate of CM and the SGR, FCR and PER of rainbow trout (P < 0.05). Growth trial results suggest at inclusion levels up to 300 g/kg, PM, PPC, SPC and CPC are feasible plant-based fish meal replacements with predictable growth effects, provided the nutritional constraints set in this experiment are followed. The results of these growth experiments were further analyzed using structural equation modeling to determine the relationship between ANF in the six ingredients and ADFI and SGR, which were transformed (tSGR and tADFI, respectively) to enable comparisons between experiments. All possible models between ingredient ANF (starch, phytic acid, glucosinolates, tannins, isoflavones, total NSP, soluble NSP, insoluble NSP and saponins) and ADFI and SGR were calculated. The model with the highest likelihood, as determined by the Akaike Information Criteria0, contained 29 parameters and six degrees of freedom. tADFI positively influenced tSGR. Glucosinolates, saponins, and phytates had a significantly negative impact on tADFI, whereas tannins had a significantly positive impact. The presence of saponins in the diet resulted in a decrease in tSGR. This structural equation model had significant correlations between all ANF, with the exception of phytates and saponins. Future applications of this work will be to develop a nutritional model for optimal inclusion of plant-based feed ingredients in rainbow trout diets, based on their ANF content, which may improve the accuracy of diet formulation and growth prediction.

Este trabalho iniciou-se com o objetivo de superexpressar proteínas com atividade ATPase, como tentativa de alterar a conservação de energia livre na levedura S. cerevisiae, de maneira a aumentar o rendimento da fermentação alcoólica. Para isso, duas ATPases nativas de S. cerevisiae, as chaperonas codificadas pelos genes HSP104 e CDC48, foram superexpressas, individualmente, sob o controle de quatro promotores de diferentes forças, provocando diferentes gastos energéticos na levedura. Entretanto, não foi possível obter aumento no rendimento em etanol. Em seguida, foi feito um estudo que visou comparar essas linhagens em situação de estresse térmico, ácido ou osmótico, tipicamente encontrados no processo brasileiro de produção de etanol. A 40 °C, uma linhagem superexpressando CDC48 apresentou velocidade específica máxima de crescimento 17 % maior que a linhagem de referência, indicando maior tolerância ao estresse térmico. Finalmente, avaliou-se Hsp104 e Cdc48 em um contexto fisiológico no qual as atividades dessas proteínas pudessem ser mais requeridas. Como as chaperonas moleculares são conhecidas por agirem como primeira linha de defesa contra a formação de proteínas incorretamente enoveladas e agregados proteicos, estudaram-se a morfologia e a fisiologia da superexpressão de HSP104 e CDC48 em linhagens com desarranjo no controle de qualidade de proteínas intracelulares, causado por mutações no proteassomo 20S. A superexpressão de CDC48 ou HSP104 reverteu em parte a morfologia alterada de alguns desses mutantes de proteassomo. / The initial goal of this work was to overexpress proteins with ATPase activity in Saccharomyces cerevisiae, as an attempt to alter the conservation of free energy in this yeast, in order to increase alcoholic fermentation yield. Therefore, two native S. cerevisiae ATPases, the chaperones encoded by HSP104 and CDC48, were individually overexpressed under the control of four promoters with different strengths, in order to provoke different levels of energy expenditure. Increments in the ethanol yield could not be observed in any of the constructed strains. Subsequently, a study was carried out to compare these mutant strains with reference strains under heat, acid or osmotic stress, which are typically found in the industrial fuel ethanol production in Brazil. At 40 oC a strain overexpressing CDC48 displayed a maximum specific growth rate 17 % higher than that of the reference strain, indicating a greater tolerance to heat stress. Finally, Hsp104 and Cdc48 were evaluated in a physiological context in which the activity of these proteins would be required in a higher level. Since molecular chaperones are known to act as the first defense line against the formation of misfolded proteins and aggregates, the physiological and morphological effects of HSP104 or CDC48 overexpression were analyzed in strains with protein quality control disarrangements caused by mutations in proteasome 20S. The overexpression of either CDC48 or HSP104 partially reversed the altered morphology of some of these proteasome mutants.

The recombinant product is secreted to the periplasm in many processes where E. coli is used as host. One drawback with secretion is the undesired leakage of the periplasmic products to the medium. The aim of this work was to find strategies to influence the periplasmic retention of recombinant products. We have focused on the role of the specific growth rate, a parameter that is usually controlled in industrial bioprocesses. The hypothesis was that the stability of the outer membrane in E. coli is gained from a certain combination of specific phospholipids and fatty acids on one side and the amount and specificity of the outer membrane proteins on the other side, and that the specific growth rate influences this structure and therefore can be used to control the periplasmic retention. We found that is possible to control the periplasmic retention by the growth rate. The leakage of the product increased as the growth rate increased. It was however also found that a higher growth rate resulted in increased productivity. This resulted in equal amounts of product inside the cells regardless of growth rate. We also showed that the growth rate influenced the outer membrane composition with respect to OmpF and LamB while OmpA was largely unaffected. The total amount of outer membrane proteins decreased as the growth rate increased. There were further reductions in outer membrane protein accumulation when the recombinant product was secreted to the periplasm. The lowered amount of outer membrane proteins may have contributed to the reduced ability for the cell to retain the product in the periplasm. The traditional way to control the growth rate is through a feed of substrate in a fed-batch process. In this work we used strains with a set of mutations in the phosphotransferase system (PTS) with a reduced uptake rate of glucose to investigate if these strains could be used for growth rate control in batch cultivations without the use of fed-batch control equipment. The hypothesis was that the lowering of the growth rate on cell level would result in the establishment of fed-batch similar conditions. This study showed that it is possible to control the growth rate in batch cultivations by using mutant strains with a decreased level of substrate uptake rate. The mutants also produced equivalent amounts of acetic acid as the wild type did in fed-batch cultivation with the same growth rate. The oxygen consumption rates were also comparable. A higher cell density was reached with one of the mutants than with the wild type in batch cultivations. It is possible to control the growth rate by the use of the mutants in small-scale batch cultivations without fed-batch control equipment. / QC 20101108

The main objective of this diploma thesis is compare the production efficiency of special types of feed for African catfish in experimental conditions in a recirculating system with biological treatment of water. It was tested four different types of floating feed, differing in the proportion of main components, the chemical composition and determining - for catfish (CatCo GROWER - 12 EF, CatCo SELECT - 13 EF and CatCo GROWER - 13 EF), respectively salmonid fish species (Dibaq Trout Evolution). The primary outcome indicators was the growth rate, individual weight (and it's variability), feed conversion ratio, the cost of feed consumed per unit of growth and product quality, evaluated according the average dress-out percentage of skinless fillets, organoleptic assessment and chemical composition of flesh.

The present thesis employs ideas of set invariance and sliding modes in order to deal with different relevant problems control of nonlinear systems. Initially, it reviews the techniques of set invariance as well as the more relevant results about sliding modes control. Then the main methodologies used are presented: sliding mode reference conditioning, second order sliding modes and continuous approximation of sliding modes. Finally, the methodologies are applied to different problems in control theory and to a variety of biologically inspired applications. The contributions of the thesis are: The development of a method to coordinate dynamical systems with different dynamic properties by means of a sliding mode auxiliary loop shaping the references given to the systems as function of the local and global goals, the achievable performance of each system and the available information of each system. Design methods for second order sliding mode algorithms. The methods decouple the problem of stability analysis from that of finite-time convergence of the super-twisting sliding mode algorithm. A nonlinear change of coordinates and a time-scaling are used to provide simple, yet flexible design methods and stability proofs. Application of the method to the design of finite-time convergence estimators of bioprocess kinetic rates and specific biomass growth rate, from biomass measurements. Also the estimators are validated with experimental data. The proposal of a strategy to reduce the variability of a cell-to-cell communication signal in synthetic genetic circuits. The method uses set invariance and sliding mode ideas applied to gene expression networks to obtain a reduction in the variance of the communication signal. Experimental approaches available to modify the characteristics of the gene regulation function are described. / Vignoni, A. (2014). Invariance and Sliding Modes. Application to coordination of multi-agent systems, bioprocesses estimation, and control in living cells [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37743 / Alfresco

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