Cultivo de microalgas para produção de biossurfactantes

Há uma crescente procura por alimentos mais saudáveis e seguros para atender uma população cada vez maior e mais exigente. Nos últimos anos o interesse por surfactantes de origem microbiana tem aumentado significativamente em decorrência de serem naturalmente biodegradáveis diminuindo assim o impacto ambiental. Uma grande variedade de microorganismos produz biossurfactantes, sendo que o tipo, a quantidade e a qualidade do biossurfactante são influenciados pelos constituintes do meio, tais como, fontes de carbono, nitrogênio e sais inorgânicos, além das condições de cultivo, como pH, temperatura, agitação e disponibilidade de oxigênio. Os biossurfactantes são metabólitos microbianos de superfície ativa que apresentam uma vasta aplicação no setor industrial. Os objetivos deste trabalho foram selecionar microalgas com potencial para produzir biossurfactantes e estudar a produção por microalgas em diferentes fotobiorreatores e condições nutricionais. O trabalho foi dividido em quatro etapas: 1) cultivo autotrófico e mixotrófico de microalgas para produção de biossurfactantes; 2) Seleção de microalgas para produção de biossurfactantes; 3) Produção de biossurfactantes por microalgas em diferentes fotobiorreatores e 4) Cultivo outdoor da microalga marinha Tetraselmis suecica OR para produção de biossurfactantes. Na primeira etapa Spirulina sp. LEB-18, Synechococcus nidulans LEB-25, Chlorella vulgaris LEB-106, Chlorella minutissima LEB-108 e Chlorella homosphaera foram cultivadas com glicose (cultivo mixotrófico). Spirulina sp. LEB-18 apresentou concentrações máximas de biomassa (2,55 g.L-1 ) quando foi utilizada 5 g.L-1 de glicose no meio de cultivo. A tensão superficial dos meios das microalgas foi reduzida de 70 para 43 mN.m-1 para as microalgas estudadas utilizando glicose como fonte de carbono. Resultados da segunda etapa mostraram que a microalga Scenedesmus sp. 3PAV3 apresentou valor de atividade emulsificante óleo em água (AE o/a) superior (339,8 UE.g-1 ) ao encontrado para as demais microalgas. Os menores valores de tensões superficiais variaram de 27,4 a 31,2 mN.m-1 . Na terceira etapa verificou-se que a microalga Chlorella sp. PROD1 apresentou valor de AE o/a semelhante (258,2 UE g -1 ) ao encontrado para o emulsificante comercial lecitina de soja (257,0 UE g -1 ) e ambas as microalgas estudadas alcançaram valores de tensões superficiais abaixo de 30 mN.m -1 . Na última etapa, Tetraselmis suecica OR cultivada em fotobiorreator do tipo Green Wall Panel apresentou menores valores de tensões superficiais para cultura com limitação de nitrogênio. Os resultados demonstraram a potencialidade das microalgas estudadas na produção de biossurfactantes, tanto pela redução da tensão superficial e interfacial, como pelo aumento da atividade emulsificante, confirmando uma possível aplicação como emulsificante, detergente, lubrificante, estabilizante, entre outras.

Microfluidic platforms for the characterization of in meso membrane protein crystallization

Membrane proteins, which reside in the membranes of cells, play a critical role in many important biological processes including cellular signaling, immune response, and material and energy transduction. Because of their key role in maintaining the environment within cells and facilitating intercellular interactions, understanding the function of these proteins is of tremendous medical and biochemical significance. Indeed, the malfunction of membrane proteins has been linked to numerous diseases including diabetes, cirrhosis of the liver, cystic fibrosis, cancer, Alzheimer's disease, hypertension, epilepsy, cataracts, tubulopathy, leukodystrophy, Leigh syndrome, anemia, sensorineural deafness, and hypertrophic cardiomyopathy.1-3 However, the structure of many of these proteins and the changes in their structure that lead to disease-related malfunctions are not well understood. Additionally, at least 60% of the pharmaceuticals currently available are thought to target membrane proteins, despite the fact that their exact mode of operation is not known.4-6 Developing a detailed understanding of the function of a protein is achieved by coupling biochemical experiments with knowledge of the structure of the protein. Currently the most common method for obtaining three-dimensional structure information is X-ray crystallography. However, no a priori methods are currently available to predict crystallization conditions for a given protein.7-14 This limitation is currently overcome by screening a large number of possible combinations of precipitants, buffer, salt, and pH conditions to identify conditions that are conducive to crystal nucleation and growth.7,9,11,15-24 Unfortunately, these screening efforts are often limited by difficulties associated with quantity and purity of available protein samples. While the two most significant bottlenecks for protein structure determination in general are the (i) obtaining sufficient quantities of high quality protein samples and (ii) growing high quality protein crystals that are suitable for X-ray structure determination,7,20,21,23,25-47 membrane proteins present additional challenges. For crystallization it is necessary to extract the membrane proteins from the cellular membrane. However, this process often leads to denaturation. In fact, membrane proteins have proven to be so difficult to crystallize that of the more than 66,000 structures deposited in the Protein Data Bank,48 less than 1% are for membrane proteins, with even fewer present at high resolution (< 2Å)4,6,49 and only a handful are human membrane proteins.49 A variety of strategies including detergent solubilization50-53 and the use of artificial membrane-like environments have been developed to circumvent this challenge.43,53-55 In recent years, the use of a lipidic mesophase as a medium for crystallizing membrane proteins has been demonstrated to increase success for a wide range of membrane proteins, including human receptor proteins.54,56-62 This in meso method for membrane protein crystallization, however, is still by no means routine due to challenges related to sample preparation at sub-microliter volumes and to crystal harvesting and X-ray data collection. This dissertation presents various aspects of the development of a microfluidic platform to enable high throughput in meso membrane protein crystallization at a level beyond the capabilities of current technologies. Microfluidic platforms for protein crystallization and other lab-on-a-chip applications have been well demonstrated.9,63-66 These integrated chips provide fine control over transport phenomena and the ability to perform high throughput analyses via highly integrated fluid networks. However, the development of microfluidic platforms for in meso protein crystallization required the development of strategies to cope with extremely viscous and non-Newtonian fluids. A theoretical treatment of highly viscous fluids in microfluidic devices is presented in Chapter 3, followed by the application of these strategies for the development of a microfluidic mixer capable of preparing a mesophase sample for in meso crystallization at a scale of less than 20 nL in Chapter 4. This approach was validated with the successful on chip in meso crystallization of the membrane protein bacteriorhodopsin. In summary, this is the first report of a microfluidic platform capable of performing in meso crystallization on-chip, representing a 1000x reduction in the scale at which mesophase trials can be prepared. Once protein crystals have formed, they are typically harvested from the droplet they were grown in and mounted for crystallographic analysis. Despite the high throughput automation present in nearly all other aspects of protein structure determination, the harvesting and mounting of crystals is still largely a manual process. Furthermore, during mounting the fragile protein crystals can potentially be damaged, both from physical and environmental shock. To circumvent these challenges an X-ray transparent microfluidic device architecture was developed to couple the benefits of scale, integration, and precise fluid control with the ability to perform in situ X-ray analysis (Chapter 5). This approach was validated successfully by crystallization and subsequent on-chip analysis of the soluble proteins lysozyme, thaumatin, and ribonuclease A and will be extended to microfluidic platforms for in meso membrane protein crystallization. The ability to perform in situ X-ray analysis was shown to provide extremely high quality diffraction data, in part as a result of not being affected by damage due to physical handling of the crystals. As part of the work described in this thesis, a variety of data collection strategies for in situ data analysis were also tested, including merging of small slices of data from a large number of crystals grown on a single chip, to allow for diffraction analysis at biologically relevant temperatures. While such strategies have been applied previously,57,59,61,67 they are potentially challenging when applied via traditional methods due to the need to grow and then mount a large number of crystals with minimal crystal-to-crystal variability. The integrated nature of microfluidic platforms easily enables the generation of a large number of reproducible crystallization trials. This, coupled with in situ analysis capabilities has the potential of being able to acquire high resolution structural data of proteins at biologically relevant conditions for which only small crystals, or crystals which are adversely affected by standard cryocooling techniques, could be obtained (Chapters 5 and 6). While the main focus of protein crystallography is to obtain three-dimensional protein structures, the results of typical experiments provide only a static picture of the protein. The use of polychromatic or Laue X-ray diffraction methods enables the collection of time resolved structural information. These experiments are very sensitive to crystal quality, however, and often suffer from severe radiation damage due to the intense polychromatic X-ray beams. Here, as before, the ability to perform in situ X-ray analysis on many small protein crystals within a microfluidic crystallization platform has the potential to overcome these challenges. An automated method for collecting a "single-shot" of data from a large number of crystals was developed in collaboration with the BioCARS team at the Advanced Photon Source at Argonne National Laboratory (Chapter 6). The work described in this thesis shows that, even more so than for traditional structure determination efforts, the ability to grow and analyze a large number of high quality crystals is critical to enable time resolved structural studies of novel proteins. In addition to enabling X-ray crystallography experiments, the development of X-ray transparent microfluidic platforms also has tremendous potential to answer other scientific questions, such as unraveling the mechanism of in meso crystallization. For instance, the lipidic mesophases utilized during in meso membrane protein crystallization can be characterized by small angle X-ray diffraction analysis. Coupling in situ analysis with microfluidic platforms capable of preparing these difficult mesophase samples at very small volumes has tremendous potential to enable the high throughput analysis of these systems on a scale that is not reasonably achievable using conventional sample preparation strategies (Chapter 7). In collaboration with the LS-CAT team at the Advanced Photon Source, an experimental station for small angle X-ray analysis coupled with the high quality visualization capabilities needed to target specific microfluidic samples on a highly integrated chip is under development. Characterizing the phase behavior of these mesophase systems and the effects of various additives present in crystallization trials is key for developing an understanding of how in meso crystallization occurs. A long term goal of these studies is to enable the rational design of in meso crystallization experiments so as to avoid or limit the need for high throughput screening efforts. In summary, this thesis describes the development of microfluidic platforms for protein crystallization with in situ analysis capabilities. Coupling the ability to perform in situ analysis with the small scale, fine control, and the high throughput nature of microfluidic platforms has tremendous potential to enable a new generation of crystallographic studies and facilitate the structure determination of important biological targets. The development of platforms for in meso membrane protein crystallization is particularly significant because they enable the preparation of highly viscous mixtures at a previously unachievable scale. Work in these areas is ongoing and has tremendous potential to improve not only current the methods of protein crystallization and crystallography, but also to enhance our knowledge of the structure and function of proteins which could have a significant scientific and medical impact on society as a whole. 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Studying and measuring the amount of detergents in sea-water samples in order to eliminate with adsorbents and inorganic nano-adsorbents for the sake of securing the water for marine nourishment pools

Increasing the amount of detergent industries in world in spite of having abundant benefits; entering a new kind of contamination into environment and attract the attention of environment liable of different countries to itself. Entering detergents into an aqueous solution cause pollution of water sources and environment in respect of appearing e problem and charges like: nutritive phenomenon, decomposition of hard group of detergent and producing foam. After using Detergents, they were poured into rivers, seas and lakes and have destructive effect on environment. A lot of hygiene problems were attributed to the water having detergents more than allowed value. So, it is specified the importance of eliminating detergents from contaminated water and it is application for secondary use. In order to attain to this aim, we can use inorganic nano and micro-caolin. In this study the adsorptive properties of detergent on the micro and nano caolin adsorbents were studied and the effect of various parameters like the amount of adsorptive materials, initial concentration of detergent, speed of stirring, electrolyte, temperature, time and pH were determined. The surface area of micro- and nano-caoline was reported 11.867 and 49.1438 m2 g-1, respectively. That increasing in nano-caoline surface area confirms increasing in capacity and more rate of adsorption. The results gained by this research recommend using micro- and nano-caolin as a plentiful, available and effective adsorbents. Also in comparison, using nano-caoline was recommended in order to have more effectiveness.

Développement et validation d’une méthode de dosage des traces de détergents inactivants totaux du prion

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Grazing behavior of lactating Murrah buffalo cows supplemented with cupuassu byproduct.

The goal of this work was to evaluate grazing behavior of lactating Murrah buffalo cows supplemented with cupuassu byproduct containing 16.8, 51.4, 8.3, 83.5 and 3.4% of ether extract (EE), neutral detergent fiber (NDF), crude protein (CP), total digestible nutrients (TDN) and nonfibrous carbohydrate (NFC), respectively. Experimental rations were balanced for reaching levels of 22.0 % of crude protein (CP) and 80.1 % of total digestible nutrient (TDN).

Effects of forage type and extruded linseed supplementation on methane production and milk fatty acid composition of lactating dairy cows

Replacing dietary grass silage (GS) with maize silage (MS) and dietary fat supplements may reduce milk concentration of specific saturated fatty acids (SFA) and can reduce methane production by dairy cows. The present study investigated the effect of feeding an extruded linseed supplement on milk fatty acid (FA) composition and methane production of lactating dairy cows, and whether basal forage type, in diets formulated for similar neutral detergent fiber and starch, altered the response to the extruded linseed supplement. Four mid-lactation Holstein-Friesian cows were fed diets as total mixed rations, containing either high proportions of MS or GS, both with or without extruded linseed supplement, in a 4×4 Latin square design experiment with 28-d periods. Diets contained 500 g of forage/kg of dry matter (DM) containing MS and GS in proportions (DM basis) of either 75:25 or 25:75 for high MS or high GS diets, respectively. Extruded linseed supplement (275 g/kg ether extract, DM basis) was included in treatment diets at 50 g/kg of DM. Milk yields, DM intake, milk composition, and methane production were measured at the end of each experimental period when cows were housed in respiration chambers. Whereas DM intake was higher for the MS-based diet, forage type and extruded linseed had no significant effect on milk yield, milk fat, protein, or lactose concentration, methane production, or methane per kilogram of DM intake or milk yield. Total milk fat SFA concentrations were lower with MS compared with GS-based diets (65.4 vs. 68.4 g/100 g of FA, respectively) and with extruded linseed compared with no extruded linseed (65.2 vs. 68.6 g/100 g of FA, respectively), and these effects were additive. Concentrations of total trans FA were higher with MS compared with GS-based diets (7.0 vs. 5.4 g/100 g of FA, respectively) and when extruded linseed was fed (6.8 vs. 5. 6g/100 g of FA, respectively). Total n-3 FA were higher when extruded linseed was fed compared with no extruded linseed (1.2 vs. 0.8 g/100 g of FA, respectively), whereas total n-6 polyunsaturated FA were higher when feeding MS compared with GS (2.5 vs. 2.1 g/100 g of FA, respectively). Feeding extruded linseed and MS both provided potentially beneficial decreases in SFA concentration of milk, and no significant interactions were found between extruded linseed supplementation and forage type. However, both MS and extruded linseed increased trans FA concentration in milk fat. Neither MS nor extruded linseed had significant effects on methane production or yield, but the amounts of supplemental lipid provided by extruded linseed were relatively small.

Increasing the value of household appliances by adding a heat pump system

Historically, domestic tasks such as preparing food and washing and drying clothes and dishes were done by hand. In a modern home many of these chores are taken care of by machines such as washing machines, dishwashers and tumble dryers. When the first such machines came on the market customers were happy that they worked at all! Today, the costs of electricity and customers’ environmental awareness are high, so features such as low electricity, water and detergent use strongly influence which household machine the customer will buy. One way to achieve lower electricity usage for the tumble dryer and the dishwasher is to add a heat pump system. The function of a heat pump system is to extract heat from a lower temperature source (heat source) and reject it to a higher temperature sink (heat sink) at a higher temperature level. Heat pump systems have been used for a long time in refrigerators and freezers, and that industry has driven the development of small, high quality, low price heat pump components. The low price of good quality heat pump components, along with an increased willingness to pay extra for lower electricity usage and environmental impact, make it possible to introduce heat pump systems in other household products. However, there is a high risk of failure with new features. A number of household manufacturers no longer exist because they introduced poorly implemented new features, which resulted in low quality and product performance. A manufacturer must predict whether the future value of a feature is high enough for the customer chain to pay for it. The challenge for the manufacturer is to develop and produce a high-performance heat pump feature in a household product with high quality, predict future willingness to pay for it, and launch it at the right moment in order to succeed. Tumble dryers with heat pump systems have been on the market since 2000. Paper I reports on the development of a transient simulation model of a commercial heat pump tumble dryer. The measured and simulated results were compared with good similarity. The influence of the size of the compressor and the condenser was investigated using the validated simulation model. The results from the simulation model show that increasing the cylinder volume of the compressor by 50% decreases the drying time by 14% without using more electricity.  Paper II is a concept study of adding a heat pump system to a dishwasher in order to decrease the total electricity usage. The dishwasher, dishware and water are heated by the condenser, and the evaporator absorbs the heat from a water tank. The majority of the heat transfer to the evaporator occurs when ice is generated in the water tank. An experimental setup and a transient simulation model of a heat pump dishwasher were developed. The simulation results show a 24% reduction in electricity use compared to a conventional dishwasher heated with an electric element. The simulation model was based on an experimental setup that was not optimised. During the study it became apparent that it is possible to decrease electricity usage even more with the next experimental setup.

Composição botânica e qualidade do pasto selecionado por ovelhas em caatinga raleada e enriquecida.

Resumo: O presente estudo foi conduzido com o objetivo de determinar a composição botânica e a qualidade da dieta selecionada por ovelhas, através da técnica de micro-histologia fecal, em caatinga raleada e enriquecida com capim massai (Panicum maximum cv. Massai), recebendo diferentes quantidades de concentrado (0; 200; 350 e 500 g de concentrado por dia), e em diferentes períodos do ano (águas, transição água-seca e seca). Foram estimados também o consumo e digestibilidade dos nutrientes, bem como a degradabilidade de espécies forrageiras ingeridas pelas ovelhas. Os experimentos foram realizados na Fazenda Crioula do Meio, pertencente a Embrapa Caprinos e Ovinos em Sobral, CE no período de março a novembro de 2013. No Experimento 1, para a determinação da composição botânica e qualidade da dieta selecionada, foram utilizadas dezesseis ovelhas Somalis brasileira, gestantes, multíparas e peso médio de 30,58+2,48 kg. O acompanhamento da ingestão do pasto pelas ovelhas foi feito em três períodos (águas, transição água-seca e seca), referentes aos meses de abril, junho e agosto de 2013, respectivamente. Amostras das plantas foram coletadas para o preparo das lâminas de referência, e posterior identificação e caracterização dos descritores epidérmicos. O mesmo foi feito para as fezes coletadas nas ovelhas. Com base na proporção de cada espécie identificada nas lâminas fecais que compuseram a dieta, e na composição química das forrageiras identificadas, foi possível determinar a qualidade da dieta ingerida. De 76 espécies observadas no pasto, 33 foram identificadas na dieta das ovelhas, destacando as espécies sabiá (Mimosa caesalpiniaefolia), centrosema (Centrosema sp.), ervanço (Alternanthera brasiliana), massai (Panicum maximum cv Massai) e paco-paco (Wissadula rostrata) como as mais selecionadas pelos animais ao longo dos períodos, chegando a compor mais de 50% da dieta selecionada. Com a chegada do período seco, espécies indesejáveis como o marmeleiro (Croton sonderianus) e o mofumbo (Combretum lepreosum), também fizeram parte das plantas selecionadas. Quanto ao valor nutritivo da dieta selecionada, os animais selecionaram uma dieta com valor nutritivo superior ao amostrado no pasto. No Experimento 2, na mesma condição do experimento anterior, trinta e duas ovelhas Somalis brasileira foram utilizadas para determinação do consumo e digestibilidade dos nutrientes, realizado em três ensaios (abril - terço final de gestação; junho - lactação e agosto - desmame). Para predição do consumo, o indicador LIPE® foi utilizado. Pesagens quinzenais foram realizadas para avaliação do desempenho das ovelhas e dos cordeiros nascidos. O concentrado oferecido favoreceu a maior ingestão e digestibilidade da MS e PB, com efeito substitutivo em relação ao consumo de pasto (P<0,05). Para o período seco, menores consumos foram observados em relação aos períodos das águas e de transição água-seca (P<0,05). Maiores consumos e digestibilidades dos constituintes fibrosos foram observados para as ovelhas não suplementados (P<0,05). Na avaliação do desempenho, a suplementação oferecida determinou os maiores pesos verificados durante a lactação, ao desmame e para os pesos ao nascer e ao desmame dos cordeiros (P<0,05). No Experimento 3, dois ovinos Morada Nova foram utilizados para determinação da degradabilidade da matéria seca (MS), proteína bruta (PB) e fibra em detergente neutro (FDN) de cinco das forrageiras selecionadas pelas ovelhas no Experimento 1: M. caesalpiniaefolia, A. brasiliana, P. maximum cv. Massai, jurema-preta (Mimosa tenuiflora), C. leprosum, nos tempos 0, 6, 24, 48, 72 e 96 horas de incubação. Para cada forrageira, foram determinadas equações para o desaparecimento da MS, PB e FDN. Também foi feito o fracionamento da proteína em suas porções degradáveis e não degradáveis no rúmen. Foi observado maior desaparecimento da MS, PB e FDN, além dos melhores níveis de proteína efetivamente degradada no rúmen para A. brasiliana, seguido pelo P. maximum cv. Massai e M. caesalpiniaefolia. Com as informações obtidas, conclui-se que a micro-histologia fecal apresenta-se como uma técnica viável para avaliações da composição botânica da dieta selecionada por ovinos na caatinga. Ovelhas na caatinga possuem uma grande habilidade de selecionar a dieta, modificando-a ao longo das fases fenológicas, sempre na tentativa de estabelecer uma dieta com melhor valor nutritivo. Forrageiras como A. brasiliana, M. caesalpiniaefolia e o P. maximum cv. Massai, podem ser consideradas um interessante recurso alimentar, em virtude de seu valor nutricional e aproveitamento por ovelhas criadas na caatinga. Abstract: This study was conducted in order to determine the botanical composition and diet quality selected by sheep through fecal micro-histological technique, in thinned and enriched caatinga with Massai grass (Panicum maximum cv Massai.), receiving different amounts of concentrate (0; 200; 350 and 500 g of concentrate per day) at different periods (wet, transition wet-dry and dry). Were also estimated the intake, digestibility, as well as the degradability of forage species eaten by sheep. The experiments were performed in the "Fazenda Crioula do Meio", owned by Embrapa Goats and Sheep, in Sobral, Ceará State, Brazil, from march to november 2013. In Trial 1, sixteen female, pregnant, multiparous, with average body weight of 30,58+2,48 kg Somalis brasileira breed sheep were used to determine the botanical composition and the quality of the selected diet. The monitoring of pasture intake of sheep were conducted in three phenological periods of the caatinga's pasture (wet season, transition wet-dry and dry season). Plant samples were collected for the preparation of the reference slides, with subsequent identification and characterization of epidermal descriptors. The same was done for the feces collected in sheep. Considering the proportion of each species identified in fecal slides which composed the diet, and the chemical composition of forage identified, it was possible to determine the quality of the selected diet. From 76 species observed in the pasture, 33 species was identified in the sheep selected diet, emphasizing the Sabiá (Mimosa caesalpiniaefolia), centrosema (Centrosema sp.), ervanço (Alternanthera brasiliana), massai (Panicum maximum cv Massai) e paco-paco (Wissadula rostrata) as the most selected species by sheep during the study, composing more than 50% of the selected diet. In the Dry Season, undesirable species like marmeleiro (Croton sonderianus) and mofumbo (Combretum leprosum), were also constituent of the diet. Regarding to the nutritional value of selected diet, the sheep selected a diet with more protein than the sampled in the pasture. In the final late gestation, the sheep without supplementation ate a diet above 16% of CP, higher than the selected diet by treatments 350 and 500 g of concentrate per day (P<0.05). Were also observed to the non supplemented sheep, less fiber content intake (P<0.05). In the Trial 2, in the same condition of the first Trial, thirty two Somalis brasileira female sheep were used to determine the intake and digestibility, conducted in three assays (April - third late pregnancy; June - lactation and August - weaning). To predict the intake, the marker LIPE was used. Sheep and lambs were weighted every two weeks to performance evaluation. The concentrate offered to sheep favored to higher intake and digestibility of DM and CP than non supplemented sheep, with inverse relationship to the pasture intake (P<0.05). For the Dry Season, lower intake were observed than for Wet Season and Transition Wet-Dry (P<0.05). Higher intakes and digestibility of the fiber constituents were verified to non supplemented sheep (P<0.05). To performance evaluation, the offered supplementation determined the higher weights observed during lactation and weaning of sheep, and to birth and weaning weights of lambs (P<0.05). In Trial 3, two male sheep were used to determine the degradability of dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) of five forages selected by sheep in Trial 1: M. caesalpiniaefolia, A. brasiliana, P. maximum cv. Massai, jurema-preta (Mimosa tenuiflora) and C. lepreosum, at zero, 6, 24, 48, 72 and 96 hours of incubation. For each forage, were determined equations for the disappearance of DM, CP and NDF. It was also realized the protein fractions in their degradable and non-degradable in the rumen parts. Was detected a higher disappearance of DM, CP and NDF, as also better proportion of the rumen degradable protein to A. brasiliana, followed by P. maximum cv. Massai and M. caesalpiniaefolia. With the information obtained, it is concluded that the fecal micro histological technique presents as a viable technique to evaluate the selected diet by sheep in caatinga's pasture. On this pasture, the sheep are skilled to select the diet, changing during the phenological phases, trying to form a diet of better nutritive value. Forages as A. brasiliana, P. maximum cv. Massai and M. caesalpiniaefolia, can be considered an interesting food source to ewes kept in the caatinga.

Uso da espectroscopia de reflectância do infravermelho próximo (NIRS) para previsão da composição bromatológica de vagens de algaroba e palma forrageira.

Espécies forrageiras adaptadas às condições semiáridas são uma alternativa para reduzir os impactos negativos na cadeia produtiva de ruminantes da região Nordeste brasileira devido à sazonalidade na oferta de forragem, além de reduzir custo com o fornecimento de alimentos concentrados. Dentre as espécies, a vagem de algaroba (Prosopis juliflora SW D.C.) e palma forrageira (Opuntia e Nopalea) ganham destaque por tolerarem o déficit hídrico e produzirem em períodos onde a oferta de forragem está reduzida, além de apresentam bom valor nutricional e serem bem aceitas pelos animais. Porém, devido à variação na sua composição, seu uso na alimentação animal exige o conhecimento profundo da sua composição para a elaboração de dietas balanceadas. No entanto, devido ao custo e tempo para análise, os produtores não fazem uso da prática de análise da composição químico-bromatológica dos alimentos. Por isto, a espectroscopia de reflectância no infravermelho próximo (NIRS) representa uma importante alternativa aos métodos tradicionais. Objetivou-se com este estudo desenvolver e validar modelos de predição da composição bromatológica de vagem de algaroba e palma forrageira baseados em espectroscopia NIRS, escaneadas em dois modelos de equipamentos e com diferentes processamentos da amostra. Foram coletadas amostras de vagem de algaroba nos estados do Ceará, Bahia, Paraíba e Pernambuco, e amostras de palma forrageira nos estados do Ceará, Paraíba e Pernambuco, frescas (in natura) ou pré-secas e moídas. Para obtenção dos espectros utilizaram-se dois equipamentos NIR, Perten DA 7250 e FOSS 5000. Inicialmente os alimentos foram escaneados in natura em aparelho do modelo Perten, e, com o auxílio do software The Unscrambler 10.2 foi selecionado um grupo de amostras para o banco de calibração. As amostras selecionadas foram secas e moídas, e escaneadas novamente em equipamentos Perten e FOSS. Os valores dos parâmetros de referência foram obtidos por meio de metodologias tradicionalmente aplicadas em laboratório de nutrição animal para matéria seca (MS), matéria mineral (MM), matéria orgânica (MO), proteína bruta (PB), estrato etéreo (EE), fibra solúvel em detergente neutro (FDN), fibra solúvel em detergente ácido (FDA), hemicelulose (HEM) e digestibilidade in vitro da matéria seca (DIVMS). O desempenho dos modelos foi avaliado de acordo com os erros médios de calibração (RMSEC) e validação (RMSECV), coeficiente de determinação (R2 ) e da relação de desempenho de desvio dos modelos (RPD). A análise exploratória dos dados, por meio de tratamentos espectrais e análise de componentes principais (PCA), demonstraram que os bancos de dados eram similares entre si, dando segurança de desenvolver os modelos com todas as amostras selecionadas em um único modelo para cada alimento, algaroba e palma. Na avaliação dos resultados de referência, observou-se que a variação dos resultados para cada parâmetro corroboraram com os descritos na literatura. No desempenho dos modelos, aqueles desenvolvidos com pré-processamento da amostra (pré-secagem e moagem) se mostraram mais robustos do que aqueles construídos com amostras in natura. O aparelho NIRS Perten apresentou desempenho semelhante ao equipamento FOSS, apesar desse último cobrir uma faixa espectral maior e com intervalos de leituras menores. A técnica NIR, associada ao método de calibração multivariada de regressão por meio de quadrados mínimos (PLS), mostrou-se confiável para prever a composição químico-bromatológica de vagem de algaroba e da palma forrageira. Abstract: Forage species adapted to semi-arid conditions are an alternative to reduce the negative impacts in the feed supply for ruminants in the Brazilian Northeast region, due to seasonality in forage availability, as well as in the reducing of cost by providing concentrated feedstuffs. Among the species, mesquite pods (Prosopis juliflora SW DC) and spineless cactus (Opuntia and Nopalea) are highlighted for tolerating the drought and producion in periods where the forage is scarce, and have high nutritional value and also are well accepted by the animals. However, its use in animal diets requires a knowledge about its composition to prepare balanced diets. However, farmers usually do not use feed composition analysis, because their high cost and time-consuming. Thus, the Near Infrared Reflectance Spectroscopy in the (NIRS) is an important alternative to traditional methods. The objective of this study to develop and validate predictive models of the chemical composition of mesquite pods and spineless cactus-based NIRS spectroscopy, scanned in two different spectrometers and sample processing. Mesquite pods samples were collected in the states of Ceará, Bahia, Paraiba and Pernambuco, and samples of forage cactus in the states of Ceará, Paraíba and Pernambuco. In order to obtain the spectra, it was used two NIR equipment: Perten DA 7250 and FOSS 5000. sSpectra of samples were initially obtained fresh (as received) using Perten instrument, and with The Unscrambler software 10.2, a group of subsamples was selected to model development, keeping out redundant ones. The selected samples were dried and ground, and scanned again in both Perten and FOSS instruments. The values of the reference analysis were obtained by methods traditionally applied in animal nutrition laboratory to dry matter (DM), mineral matter (MM), organic matter (OM), crude protein (CP), ether extract (EE), soluble neutral detergent fiber (NDF), soluble acid detergent fiber (ADF), hemicellulose ( HEM) and in vitro digestibility of dry matter (DIVDM). The performance of the models was evaluated according to the Root Mean Square Error of Calibration (RMSEC) and cross-validation (RMSECV), coefficient of determination (R2 ) and the deviation of Ratio of performance Deviation of the models (RPD). Exploratory data analysis through spectral treatments and principal component analysis (PCA), showed that the databases were similar to each other, and may be treated asa single model for each feed - mesquite pods and cactus. Evaluating the reference results, it was observed that the variation were similar to those reported in the literature. Comparing the preprocessing of samples, the performance ofthose developed with preprocessing (dried and ground) of the sample were more robust than those built with fresh samples. The NIRS Perten device performance similar to FOSS equipment, although the latter cover a larger spectral range and with lower readings intervals. NIR technology associate do multivariate techniques is reliable to predict the bromatological composition of mesquite pods and cactus.