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- By-catch and discarding practices in five Algarve (southern Portugal) metiersPublication . Borges, Teresa C.; Erzini, Karim; Bentes, L.; Lima Costa, Maria Emília; Gonçalves, J. M. S.; Lino, P. G.; Pais, C.; Ribeiro, J.The catches and discards of trawlers, seiners and trammel netters were studied in the Algarve (southern Portugal) using observers onboard commercial fishing vessels. Species diversity was high, with 236 species recorded as occasionally, frequently or regularly discarded. Mean discard rates per trip were 0.13, 0.20, 0.27, 0.62 and 0.70, respectively, for trammel nets, demersal purse seines, pelagic purse seines, fish trawls and crustacean trawls, with high variability in terms of discard volume and discard rate, This was especially so for se ncrs where from 0 to 100% of the total catch might be discarded. No significant relationships were found between discard quantity or discard rate and characteristics of the fishing vessels sampled within each metier (total length, TAB, hp, kW). Based on the above discard rates and the official landings, it was estimated that in 1996, Algarve trawlers discarded 9000-13000 tonnes (t) while seiners discarded 5500-8200 t. Discarding practices in these fisheries are reviewed and the reasons for discarding are presented by species and metier basis. The results support the need for more studies on the factors contributing to discarding, variability in discard quantities and rates, the fate of discards and their importance to the marine ecosystem, and on ways of reducing by-catch and discarding in these fisheries.
- A comparative study of the species composition of discards from five fisheries from the Algarve (southern Portugal)Publication . Erzini, Karim; Lima Costa, Maria Emília; Bentes, L.; Borges, T. C.Discards from five of the most important fisheries (crustacean trawling, fish trawling, demersal purse seining, pelagic purse seining and trammel netting) in southern Portugal were studied and compared. A total of 236 species of all taxa were discarded, with fish and cephalopods accounting for more than 90% of the discarded biomass, except trammel nets (81%). Although there was some overlapping of species, multivariate analysis using cluster analysis for classification and multidimensional scaling (MDS) for ordination, showed that there were significant differences between the five gears in terms of species composition and biomasses discarded, with the least similarity between crustacean trawling and all other fishing operations. The differences between fisheries were probably as a result of a combination of gear selectivity and depth fished. The results suggest that discarding practices are likely to have different, yet significant impacts on the marine ecosystem, warranting further studies on the fate of discards, the factors influencing discarding and mitigation.
- Application of the focused beam reflectance measurement method (FBRM) to the characterization of plant cells in suspension culturePublication . Jeffers, Paul; Raposo, Sara; Lima-Costa, Maria Emília; Kieran, Patricia; Glennon, BrianThe ability to determine biomass levels and organism morphological characteristics is of importance in many bioprocesses.
- The effect of ethanol on the plasma membrane permeability of spoilage yeastsPublication . Quintas, Célia; Lima-Costa, Maria Emília; Loureiro-Dias, M. C.The effect of ethanol on the passive proton influx and on leakage of compounds absorbing at 260 nm, as representatives of intracellular content, was studied on food spoilage yeasts such as Saccharomyces cerevisiae, Zygosaccharomyces bailii, Pichia sp. and Debaryomyces hansenii. For volume fraction below 10 %, the effect of ethanol on the proton influx was in general weak, but above a certain treshold of ethanol high values were observed. In Z. bailii ethanol had no effect up to 20 % (volume fraction). Previous growth of the cells in the presence of benzoic acid or ethanol did not affect the influx of protons in the presence of ethanol. Leakage of compounds absorbing at 260 nm was not observed at 25 degrees C and occurred at 30 degrees C only after a rather long incubation in high concentrations of ethanol, which induced cell death. This suggests that in the yeasts this process does not control the leakage of compounds in the presence of ethanol.
- Reproductive biology of the blackmouth catshark, Galeus melastomus (Chondrichthyes: Scyliorhinidae) off the south coast of PortugalPublication . Lima Costa, Maria Emília; Erzini, Karim; Borges, Teresa C.The reproductive biology of 1045 female (9.5-67 cm (total length(TL)) and 1007 male (9.4-64.3 cm TL) blackmouth catsharks, Galeus melastomus, was investigated. The sharks were caught off southern Portugal by bottom crustacean trawlers at depths from 209 to 754 m. The sex ratio was 1:1, and this species is sexually dimorphic with males approaching maturity at smaller size than females. Sexual segregation appears to be given for the stork within the study area. Sexual maturity was reached at a total length above 49 cm in males and above 56 cm in females. Mating and egg-deposition take place all year round, with two reproductive peaks of activity, in winter and summer. Egg capsules are, on average, 54 mm long and 21 mm wide, with a maximum of 63 x 25 mm encountered. Morphometric measurements of claspers, testes, ovaries, and oviducal glands were suitable for determining sexual maturity of blackmouth catshark.
- A structured growth model for Cynara cardunculus cell suspensionPublication . Cabral, Paula Pires; Lima Costa, Maria Emília; Cabral, J. M. S.In this study a model was developed to describe the growth of Cynara cardunculus L. suspended cells as a function of the availability of two substrates, sucrose as the carbon and energy source and phosphate. It was assumed that the maintenance energy need was fulfilled by the consumption of extracellular carbohydrates, in nonlimiting conditions, or by the consumption of structural biomass when sucrose is depleted. A production of secondary metabolites was also assumed. This model was developed based on a structured model previously described by Van Gulik et al. (1993). The model was applied to the experimental results of C. cardunculus suspended cells grown in a Gamborg B-5 medium supplemented with 2% sucrose, using a non-linear regression program.
- Reactores para cultura de células vegetaisPublication . Emília Lima-Costa, Maria; Raposo, SaraAs plantas são um valioso recurso natural para obtenção, de diversos produtos químicos com aplicações medicinais, na indústria alimentar, na indústria de detergentes, de curtumes, pesticidas, tintas entre outras. Usualmente estes compostos são obtidos por via extractiva em que a indústria química tem tido um papel determinante. Cerca de 25% dos medicamentos farmacêuticos que hoje se utiliza, são obtidos por extracção química a partir da planta in vivo. Estes produtos são, em geral, compostos com uma estrutura química nãoproteica e complexa. Os compostos de origem vegetal mais interessantes do ponto de vista comercial são aqueles em que a síntese química, devido à complexidade da estrutura molecular, é pouco viável quer por razões tecnológicas ou económicas, ou em que a síntese realizada por microrganismos não seja possível.
- Cultura em substratos orgânicos de GerberasPublication . Rosa, A.; Lima Costa, Maria Emília; Monteiro, Ileana Pardal; Reis, M.; Cabral Silva, R.; Caço, J.; Osório, JúlioO cultivo sem solo de Gerbera (Gerbera jamesonii) tem-se revelado uma técnica adequada, permitindo ultrapassar alguns dos problemas surgidos na cultura tradicional, em solo. No âmbito do Projecto Agro no197 “Cultura sem solo com reutilização do efluente, em estufa com controle ambiental melhorado”, desenvolvido pela Direcçao Regional de Agricultura do Algarve, pelo Cento de Hidroponia e Utilidades Hortofrutícolas e pela Universidade do Algarve testou-se o cultivo de gerbera em substratos alternativos, no Centro de Experimentação Hortofrutícola do Patacão. Cultivaram-se quatro cultivares de gerbera: Monika, Junkfrau, Venice e Lady, em substratos preparados à base de resíduos orgânicos: casca de pinho e bagaço de uva, durante dois anos consecutivos. Os resultados obtidos sugerem que os substratos testados apresentam características adequadas à cultura da gerbera, tendo-se obtido as produções mais elevadas com o bagaço de uva compostado e a casca de pinho não compostada. Das cv. em estudo, no 1o ano a Venice apresentou o maior número de flores comercializáveis, seguida da Lady com mais flores na classe Extra. No 2o ano, a produção foi mais equilibrada entre as cultivares, sendo de registar o aumento da produção em duas cv., Junkfrau e Monica.
- Oleaginous microorganisms as sustainable feedstock for biodiesel productionPublication . Raposo, Sara; Pardão, J.; Lima-Costa, Maria EmíliaBiodiesel has had a considerable development in the past decade. High cost of oil feedstocks and problems associated with extensive cultivation of oleaginous plants to face growing market demand, competing with the agro-food industry for agricultural resources have limited production development. This situation has raised an intense global I&D effort in the search for raw materials alternative to oleaginous plants, which are the main energy resource for biodiesel production. Promising results have been obtained with oleaginous microorganisms, Rhodosporidium toruloides and Yarrowia lipolytica, being one of the potential sources of oils for biodiesel production.
- Focussed beam reflectance measurement (FBRM) monitoring of particle size and morphology in suspension cultures of Morinda citrifolia and Centaurea calcitrapaPublication . Jeffers, Paul; Raposo, Sara; Lima-Costa, Maria Emília; Connolly, Patricia; Glennon, Brian; Kieran, PatriciaLaser light scattering technology, as applied in the Lasentec focussed beam reflectance measurement (FBRM) system, was used to characterise two morphologically dissimilar plant cell suspension cultures, Morinda citrifolia and Centaurea calcitrapa. Shake-flask suspensions were analysed in terms of biomass concentration and aggregate size/shape over the course of typical batch growth cycles. For the heavily aggregated C. calcitrapa, biomass levels [from 10-160 g fresh weight (fw) l-1)] were linearly correlated with FBRM counts. For M. citrifolia, which grows in unbranched chains of 2-10 elongated cells, linear correlation of biomass concentration with FBRM counts was applicable in the range 0-100 g fw l-1; at higher levels (100-300 g fw l-1), biomass was non-linearly correlated with FBRM counts and length-weighted average FBRM chord length. For both cell systems, particle morphology (size/shape) was quantified using semi-automated digital image analysis. The average aggregate equivalent diameter (C. calcitrapa) and average chain length (M. citrifolia), determined using image analysis, closely tracked the FBRM average chord length. The data clearly demonstrate the potential for applying the FBRM technique for rapid characterisation of plant cell suspension cultures.