7 research outputs found

    Production of fructooligosaccharides and b-fructofuranosidase by batch and repeated batch fermentation with immobilized cells of Penicillium expansum

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    The production of fructooligosaccharides (FOS) and b-fructofuranosidase (FFase) by immobilized cells of Penicillium expansum was evaluated. In an initial stage, different low-cost materials including synthetic fiber, polyurethane foam, stainless steel sponge, loofah sponge, and cork oak were tested as carrier for the fungus immobilization. Additionally, the influence of the inoculum age (1 or 3 weeks) on cells immobilization, FOS and FFase production was also verified. Synthetic fiber and polyurethane foam were the best materials for P. expansum immobilization (2.21 and 1.98 g/g carrier, respectively) and FOS production (120.3 and 104.8 g/l), and gave also high results of FFase activity (23.01 and 32.42 U/ml). Then, the production of FOS and FFase by repeated batch fermentation with P. expansum immobilized on synthetic fiber was studied, aiming to improve the batch fermentation results. The results obtained in this stage were very promising with FOS yields of 87, 72, and 44 %, in the 3 initial cycles (60 h), respectively; the FFase activity was constant throughout the process (6 cycles, 96 h). Repeated batch fermentation with immobilized cells of P. expansum was found as being a technology with great potential for FOS and FFase production on industrial scaleThe financial support from FCT, the Portuguese Foundation for Science and Technology (research grant SFRH/BPD/38212/2007) is gratefully acknowledged

    Novel peptide biomaterials against biofilms

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    The extensive use of antibiotics for human and animal care has resulted in the development of bacterial resistance towards antibiotics. Recently, great attention is devoted to the possibility to build self-assembling peptide structures with antibacterial activity but most studies are limited to self-assembling entities to verify their eventual antibacterial activity.[1,2] The objective of this research project is to have a versatile nanosystem composed of a self-assembling sequences with antimicrobial activity due to the presence of antimicrobial peptides (AMPs). For this purpose, we used two different sequences one shorter which should aid the self-assembling process and the other longer and containing two moieties, the one serving for the assembly and the one serving as antimicrobial. The antimicrobial peptide WMR[3] was used in this study and properly modified in order to be inserted the self-assembling structure. We focus on the possibility of exploiting the multivalent presentation of AMPs on self-assembled nanostructures to improve antibiofilm activity. We used several techniques for a physico-chemical characterization of the self-assembled structures and performed experiments on microorganisms to test the capability to inhibit the biofilm growth or promote the eradication. The study has demonstrated that our peptide structures are promising tool against biofilms

    Plataforma para medição de forças na região plantar de pacientes normais e hemiplégicos

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    This work describes an electronic system implementation with two force plates, 24 load cells with strain gages, signal conditioning circuit, interfacing circuit and data acquisition system, designed for measuring plantar force distribution in patients. The system presented linear response, low hysteresis, with determination coefficient of 0.9997, precision better than 0,84% and resolution less than 0.5 N. The Measurements are presented on a computer screen and easier visualization to specialists, mainly physicians, physiotherapists and occupational therapists. Using the system, the distribution of weight in the plantar region of 100 normal subjects and 10 hemiplegic patients was investigated. There were determined the relationship between weight distribution on the right and left forefoot, hemiplegic patients and normal patients, with the implemented system. © 2013 Springer

    A review of cephalopod-environment interactions in European Seas

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    Cephalopods are highly sensitive to environmental conditions and changes at a range of spatial and temporal scales. Relationships documented between cephalopod stock dynamics and environmental conditions are of two main types: those concerning the geographic distribution of abundance, for which the mechanism is often unknown, and those relating to biological processes such as egg survival, growth, recruitment and migration, where mechanisms are sometimes known and in a very few cases demonstrated by experimental evidence. Cephalopods seem to respond to environmental variation both ‘actively’ (e.g. migrating to areas with more favoured environmental conditions for feeding or spawning) and ‘passively’ (growth and survival vary according to conditions experienced, passive migration with prevailing currents). Environmental effects on early life stages can affect life history characteristics (growth and maturation rates) as well as distribution and abundance. Both large-scale atmospheric and oceanic processes and local environmental variation appear to play important roles in species–environment interactions. While oceanographic conditions are of particular significance for mobile pelagic species such as the ommastrephid squids, the less widely ranging demersal and benthic species may be more dependent on other physical habitat characteristics (e.g. substrate and bathymetry). Coastal species may be impacted by variations in water quality and salinity (related to rainfall and river flow). Gaps in current knowledge and future research priorities are discussed. Key research goals include linking distribution and abundance to environmental effects on biological processes, and using such knowledge to provide environmental indicators and to underpin fishery management
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