Produção enzimática de biodiesel a partir de resíduos agro-industriais usando a lipase imobilizada de origem microbiana

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Química e Biológica

Licenciamento Ambiental: uma ferramenta de marketing - O caso de uma empresa agro-alimentar

Mestrado em Gestão e Empreendedorismo

Decision tools for bacterial blight resistance gene deployment in rice-based agricultural ecosystems

Attempting to achieve long-lasting and stable resistance using uniformly deployed rice varieties is not a sustainable approach. The real situation appears to be much more complex and dynamic, one in which pathogens quickly adapt to resistant varieties. To prevent disease epidemics, deployment should be customized and this decision will require interdisciplinary actions. This perspective article aims to highlight the current progress on disease resistance deployment to control bacterial blight in rice. Although the model system rice-Xanthomonas oryzae pv. oryzae has distinctive features that underpin the need for a case-by-case analysis, strategies to integrate those elements into a unique decision tool could be easily extended to other crops.

Uncertainties in projecting climate-change impacts in marine ecosystems

Projections of the impacts of climate change on marine ecosystems are a key prerequisite for the planning of adaptation strategies, yet they are inevitably associated with uncertainty. Identifying, quantifying, and communicating this uncertainty is key to both evaluating the risk associated with a projection and building confidence in its robustness. We review how uncertainties in such projections are handled in marine science. We employ an approach developed in climate modelling by breaking uncertainty down into (i) structural (model) uncertainty, (ii) initialization and internal variability uncertainty, (iii) parametric uncertainty, and (iv) scenario uncertainty. For each uncertainty type, we then examine the current state-of-the-art in assessing and quantifying its relative importance. We consider whether the marine scientific community has addressed these types of uncertainty sufficiently and highlight the opportunities and challenges associated with doing a better job. We find that even within a relatively small field such as marine science, there are substantial differences between subdisciplines in the degree of attention given to each type of uncertainty. We find that initialization uncertainty is rarely treated explicitly and reducing this type of uncertainty may deliver gains on the seasonal-to-decadal time-scale. We conclude that all parts of marine science could benefit from a greater exchange of ideas, particularly concerning such a universal problem such as the treatment of uncertainty. Finally, marine science should strive to reach the point where scenario uncertainty is the dominant uncertainty in our projections.

Papel das medidas agro-ambientais na gestão da paisagem rural no concelho de Marvão no PNSSM

As paisagens rurais portuguesas construídas e mantidas ao longo dos tempos por sistemas agrícolas tradicionais, estão hoje ameaçadas por motivos tão diversos como o envelhecimento da população, o abandono rural, a intensificação, a homogeneização dos sistemas de produção e a perda de competitividade. Mas apesar destes problemas, estas paisagens agrícolas, suportam ainda várias funções não produtivas, nomeadamente, constituem, um importante suporte de biodiversidade, pelo que a sua manutenção é importante para a conservação destes habitats e espécies. Eventualmente novas formas de gestão destas paisagens devem ser criadas, nomeadamente com base na combinação de várias funções numa perspectiva de multifuncionalidade, através de uma adaptação e integração de políticas públicas. Estando actualmente em discussão o novo programa de Desenvolvimento Rural e a definição das futuras Medidas Agro-Ambientais, e a gestão e o financiamento da Rede Natura 2000, estamos portanto num momento crítico para decisões futuras, que terão forçosamente que interligar, a agricultura, o ambiente e desenvolvimento das zonas rurais portuguesas. Com o intuito de melhor compreender estas problemáticas, em particular, as transformações em curso na paisagem rural, o papel das Medidas Agro-Ambientais e apresentar possíveis soluções, foi efectuado este estudo de caso no concelho de Marvão, concelho típico das áreas marginais agrícolas do interior sul de Portugal. ABSTRACT; The Portuguese rural landscapes built up and kept throughout the times by traditional agricultural systems, are today threatened by so diverse reasons as the ageing of the population, the agricultural abandonment, the intensification, the homogenization of the production systems and the loss of competitiveness. But despite these problems. These agricultural landscapes still support a multitude of non-commodity functions, and particularly they still constitute an important support of biodiversity and thus their maintenance is important for the conservation of these habitats and species. Probably new management forms must be created based on the combination of various functions and the adaptation and integration of public policies. Being currently in discussion the new program of Rural Development and the definition of the future Agri-Environmental Measures, and the management and the financing of the Natura 2000 Network, we are therefore at a critical moment for future decisions that will forcibly have to establish connections, between the agriculture, the environment and the development of the portuguese agricultural areas. With the intention of better understanding these problems and questions, , the transformations taking place in Portuguese peripheric rural areas, and in particular role of the Agri-Environmental Measures, and also for presenting possible solutions, a case study was analyzed in municipality of Marvão, characteristic of the agricultural marginal areas of the interior Southern Portugal.

Resíduos da indústria agro-alimentar como possíveis fontes de ácido ferúlico

A indústria agro-alimentar produz anualmente uma grande quantidade de subprodutos, ainda tratados como desperdício. A indústria cervejeira, em particular, está associada à produção de vários resíduos, entre os quais o bagaço de malte, também designado bagaço de cerveja ou dreche. Sendo produzida numa razão de 20 kg por cada 100 litros de cerveja, só na Ilha da Madeira a produção de dreche ultrapassa as 2000 toneladas/ano. O presente trabalho foi realizado com o intuito de estudar a utilização da dreche como material de partida para a extracção de ácido ferúlico, um ácido hidroxicinâmico com elevada bioactividade e aplicações. A caracterização físico-química da dreche permitiu determinar um teor de humidade de aproximadamente 70% e um teor de cinzas de cerca de 3,6%. A distribuição granulométrica da dreche seca, revelou que cerca de 70% das partículas que a constituem têm dimensão entre 1 e 0,25 mm. A extracção com acetona produziu um extracto contendo 5 compostos de natureza fenólica, determinados por LC-MS. A hidrólise alcalina – uma das técnicas que permitem a extracção de compostos como o ácido ferúlico a partir de matrizes lenhocelulósicas – foi estudada em amostras de dreche submetidas a tratamento prévio. O pré-tratamento com ácido diluído demonstrou ser eficiente na extracção do ácido ferúlico a partir da dreche. A extracção em autoclave mostrou ser eficiente na extracção do ácido ferúlico [0,28% (m/m)] e uma simplificação do procedimento posterior à reacção de hidrólise alcalina fez aumentar o rendimento de extracção em cerca de 84%, comparativamente ao procedimento habitual. As condições óptimas de hidrólise alcalina em tubos autopressurizados aconteceram a 120 ºC, por 1,5 horas, num rácio de 20 mL/g e NaOH (1,5%). O processo de purificação do ácido ferúlico extraído por adsorção numa resina sintética resultou em percentagens de adsorção de 90,83% e de dessorção em torno dos 68,70%.

Hardpan and maize root distribution under conservation and conventional tillage in Agro-Ecological Zone IIA, Zambia

Hardpans (plough/hoe pans) are commonly believed to restrict plant root growth and crop yields under conventional small-scale agriculture in sub-Saharan Africa. This study questions the notion of widespread hardpans in Zambia and their remedy under conservation tillage. Soil penetration resistance was measured in 8x12 grids, covering 80 cm wide and 60 cm deep profiles in 32 soil pits. Large and fine maize roots were counted in 8x6 grids. Soil samples from mid-rows were analysed for pH, exchangeable H+, exchangeable Al3+, cation exchange capacity, total N and extractable P (Bray 1) at six depths from 0-10 to 50-60 cm. Cultivation-induced hardpans were not detected. Soils under conservation tillage were more compact at 5 cm depth than soils under conventional tillage. No differences in root distributions between conservation and conventional tillage were found. Maize ( Zea mays L. ) roots were largely confined to a relatively small soil volume of about 30 cm x 30 cm x 30 cm. Root growth appeared to be restricted by a combination of low concentrations of N and P. Soil acidity and Al saturation appeared to play a minor role in root distribution. L-shaped taproots in soils under manual tillage reported earlier were not necessarily due to hardpans, but may rather be caused by temporarily dry, impenetrable subsoils early in the rain season. There is no scientific basis for the recommendation given to farmers by agricultural extension workers to “break the hardpan” in fields under manual or animal tillage in the study areas.

Bioconversion of agro-industrial wastes for the production of fibrinolytic enzyme from Bacillus halodurans IND18: Purification and biochemical characterization

Background: Agro-wastes were used for the production of fibrinolytic enzyme in solid-state fermentation. The process parameters were optimized to enhance the production of fibrinolytic enzyme from Bacillus halodurans IND18 by statistical approach. The fibrinolytic enzyme was purified, and the properties were studied. Results: A two-level full factorial design was used to screen the significant factors. The factors such as moisture, pH, and peptone were significantly affected enzyme production and these three factors were selected for further optimization using central composite design. The optimum medium for fibrinolytic enzyme production was wheat bran medium containing 1% peptone and 80% moisture with pH 8.32. Under these optimized conditions, the production of fibrinolytic enzyme was found to be 6851 U/g. The fibrinolytic enzyme was purified by 3.6-fold with 1275 U/mg specific activity. The molecular mass of fibrinolytic enzyme was determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis, and it was observed as 29 kDa. The fibrinolytic enzyme depicted an optimal pH of 9.0 and was stable at a range of pH from 8.0 to 10.0. The optimal temperature was 60°C and was stable up to 50°C. This enzyme activated plasminogen and also degraded the fibrin net of blood clot, which suggested its potential as an effective thrombolytic agent. Conclusions: Wheat bran was found to be an effective substrate for the production of fibrinolytic enzyme. The purified fibrinolytic enzyme degraded fibrin clot. The fibrinolytic enzyme could be useful to make as an effective thrombolytic agent.

Impacts of high-nitrate freshwater inputs on macrotidal ecosystems. I. Seasonal evolution of nutrient limitation for the diatom-dominated phytoplankton of the Bay of Brest (France)

The chemical factors (inorganic nitrogen, phosphate, silicic acid) that potentially or actually control primary production were determined for the Bay of Brest, France, a macrotidal ecosystem submitted to high-nitrate-loaded freshwater inputs (winter nitrate freshwater concentrations >700 mu M, Si:N molar ratio as low as 0.2, i.e. among the lowest ever published). Intensive data collection and observations were carried out from February 1993 to March 1994 to determine the variations of physical [salinity, temperature, photosynthetically active radiation (PAR), freshwater discharges] and chemical (oxygen and nutrients) parameters and their impacts on the phytoplankton cycle (fluorescence, pigments, primary production). With insufficient PAR the winter stocks of nutrients were almost nonutilized and the nitrate excess was exported to the adjacent ocean, due to rapid tidal exchange. By early April, a diatom-dominated spring bloom developed (chlorophyll a maximum = 7.7 mu g l(-1); primary production maximum = 2.34 g C m(-2) d(-1)) under high initial nutrient concentrations. Silicic acid was rapidly exhausted over the whole water column; it is inferred to be the primary limiting factor responsible for the collapse of the spring bloom by mid-May. Successive phytoplankton developments characterized the period of secondary blooms during summer and fall (successive surface chlorophyll a maxima = 3.5, 1.6, 1.8 and 1.0 mu g l(-1); primary production = 1.24, 1.18 and 0.35 g C m(-2) d(-1)). Those secondary blooms developed under lower nutrient concentrations, mostly originating from nutrient recycling. Until August, Si and P most likely limited primary production, whereas the last stage of the productive period in September seemed to be N limited instead, this being a period of total nitrate depletion in almost the whole water column. Si limitation of spring blooms has become a common feature in coastal ecosystems that receive freshwater inputs with Si:N molar ratios <1. The peculiarity of Si Limitation in the Bay of Brest is its extension through the summer period.

Sistema da cadeia agro-alimentar : atitudes do consumidor face aos OGMs

No âmbito da uc Sistemas da Cadeia Agroalimentar, do Mestrado em Ciências do Consumo Alimentar, este texto de apoio considera o modo como o consumidor perceciona os organismos geneticamente modificados

Sistema da cadeia agro-alimentar : comunicação do produto alimentar

Neste documento (slides) considera-se a problemática do mix da comunicação (publicidade e promoções de vendas), aplicada aos bens agroalimentares. Este documento deve ser lido em sintonia com o texto de apoio sobe o mesmo tema.

Sistema da cadeia agro-alimentar : comunicação do produto alimentar

Neste documento (texto de a apoio) considera-se a problemática do mix da comunicação (publicidade e promoções de vendas), aplicada aos bens agroalimentares. Este documento deve ser lido em sintonia com os Slides sobe o mesmo tema.

Sistema da cadeia agro-alimentar : produto

Neste documento (texto de apoio) considera-se a particularmente a diferenciação dos produtos alimentares: marca e produtos tradicionais com nomes protegidos. Este documento deve ser lido em sintonia com os Slides sobe o mesmo tema.

Sistema da cadeia agro-alimentar : variáveis não controláveis pelas empresas agro-alimentares

Neste documento (Texto de apoio) considera-se a problemática das políticas de preço e de distribuição alimentar. Este documento deve ser lido em sintonia com os Slides sobe o mesmo tema.

Sistema da cadeia agro-alimentar : introdução ao sistema da cadeia agro-alimentar

Neste documento (texto de apoio) consideram-se as dimensões do sistema agroalimentar. Este documento deve ser lido em sintonia com os Slides sobe o mesmo tema.