Browsing by Author "Baeta-Hall, Lina"
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- Biodegradation ability of three bacterial strains isolated from a Jacto reactor used for the treatment of an agro-industrial effluentPublication . Eusebio, Ana; Mateus, Marta; Baeta-Hall, Lina; Sàágua, M. C.; Gadanho, M.; Tenreiro, R.; Almeida-Vara, Elsa; Duarte, José Cardoso
- Bioethanol production from agricultural wastesPublication . Duarte, José Cardoso; Sàágua, M. C.; Baeta-Hall, Lina; Correia, Anabela; Ribeiro, Belina; Lourenço, V.; Pereira, J.; Paixão, Susana M.In this study, different strains of Saccharomyces cerevisiae have been screened for the ability of bioethanol production. Yeasts were grown in synthetic liquid medium containing two different substrates: sucrose at different concentrations (10 to 400g/l) and cane molasses (120g/l of sucrose). The screening was made in batch regime and the growth rates, ethanol and biomass productions were determined. The results indicate a flocculent yeast strain – F as the more suitable microorganism to produce ethanol, presenting the highest value of growth rate (0.49h-1) and ethanol yield (0.40g/g) with 120g/l of sucrose concentration. In addition, ethanol production was also studied in a continuous process with the selected yeast strain (F strain), with sucrose and cane molasses (120g/l) at different dilution rates (0.05-0.5 h-1). Data showed that when dilution rate raised to 0.4h-1 the highest sugar conversion, 85% and 90%, were achieved with an ethanol production of 40.5g/l and 50.8g/l for sucrose and molasses, respectively.
- Characterisation of a microbial consortium involved in the winery effluent bio-treatmentPublication . Eusebio, Ana; Mateus, Marta; Baeta-Hall, Lina; Almeida-Vara, Elsa; Duarte, José Cardoso
- Detoxification of olive mill wastewaters using a packed-bed batch reactorPublication . Paixão, Susana M.; Sàágua, M. C.; Baeta-Hall, Lina; Correia, Anabela; Ribeiro, Belina; Duarte, José CardosoOlive oil production is a traditional agricultural industry in Mediterranean countries and Portugal is one of the ten major producers. This industry generates an effluent, olive mill wastewater (OMW), which does not undergo any treatment and, usually, is stored in evaporation lagoons or spread on the land. Disposal of olive oil mill wastewaters is a serious environmental problem due to its high organic loading, presence of polyphenols and tannins, high content in suspended solids and acidity, which contributes to its ecotoxicity. In this work, a biological treatment system: a packed-bed batch reactor was applied to a Portuguese OMW using its autochthon microbial population as inoculum. Thus, the biodegradation potential of OMW’ microrganisms naturally present in these wastewaters was assessed monitoring several physico-chemical parameters along the process. Ecotoxicity tests (Pseudomonas putida growth inhibition test and Vibrio fisheri growth inhibition test) were carried out to follow the detoxification capacity of the system as well as its potential to be used in the treatment of this type of agroindustrial effluent. In this aerobic treatment, an active microbial community with high degradation ability for the OMW organic load was detected, accounting for 80%, 71% and 61% removal of COD, TSS and phenols, respectively. In addition, a significant decrease in the chronic toxicity of the treated OMW to both bacteria, V. fisheri (62.8%) and P. putida (64.3%), was also observed after 140 days of treatment, highlighting the detoxification potential of the system studied
- Ethanol production from enzymatically pretreated wheat strawPublication . Duarte, José Cardoso; Pereira, Joana; Paixão, Susana M.; Baeta-Hall, Lina; Ribeiro, Belina; Sàágua, M. C.Lignocellulosic biomass can be utilized to produce ethanol, a promising alternative energy source for the limited crude oil. Wheat straw is an abundant agricultural residue which can be used as lignocellulosic raw material for bioconversion. There are mainly two processes involved in the bioconversion: hydrolysis of cellulose in the lignocellulosic biomass to produce reducing sugars, and fermentation of the sugars to ethanol. The current study involved the optimization of enzymatic hydrolysis of a wheat straw pretreated by acid hydrolysis, using a mixture of commercial cellulases: celluclast 1.5L + Novozym 188, with further fermentation of the hydrolisate’ sugar content by three ethanologenic strains, namely two yeast of Saccharomyces cerevisiae (strains F and K) and a bacterial strain, Zymomonas mobilis (strain CP4). The fermentation assays, using undiluted hydrolisate with or without nutrient supplements, were monitored by the evaluation of glucose and ethanol yields. In the assays using no supplemented hydrolisate the results obtained for the two yeasts strains F and K, and Zymomonas mobilis were 74%, 79% and 58% of ethanol yield, respectively. However, when the hydrolisate was supplemented the fermentation results showed a better bioconversion process by the Z. mobilis, reaching 98% ethanol yield while the two strains of S. cerevisiae used maintained their behaviour. So, the fermentation results showed the necessity of the addition of nutrients for a good bioconversion process by the Z. mobilis, resulting in better ethanol yield than S. cerevisiae strains (F and K) from WSP hydrolisate.
- Functional screening of a metagenomic library obtained from soils water of S. Domingos's minePublication . Pereira, Paula Sá; Baeta-Hall, Lina; Sàágua, M. C.; Paixão, Susana M.; Duarte, José Cardoso; Anselmo, Ana
- Kinetics of a packed-bed bacth reactor for the treatment of olive oil wastewaters from a Portuguese millPublication . Ribeiro, Belina; Correia, Anabela; Baeta-Hall, Lina; Sàágua, M. C.; Duarte, José CardosoOlive oil production is a traditional agricultural industry in Mediterranean countries and Portugal is one of the ten major producers. This industry generates an effluent, olive mill wastewater. This effluent does not undergo any treatment and is usually stored in evaporation lagoons or spread on the land. This can have a negative impact in the environment since this effluent has a high level of organic matter leading to a high chemical oxygen demand. In addition it has also a high content of polyphenols that contributes to the ecotoxicity of this effluent.Different techniques for the treatment of these wastewaters have been studied. In this work a 60 litre vessel was filled with a packaging of plastic material consisting of a cubic geometry (Biological Carrier Media from Rauschert). The non-inoculated reactor was filled with effluent from an olive mill farm (from Alfândega da Fé, Trás-os-Montes) and the effluent was re-circulated daily for homogeneity. COD, colour, nitrogen, solids and phosphorous were measured to follow the evolution of the system. Microbial composition and polyphenols were also evaluated. As an indicator of the microbial activity in the reactor, lipase activities were measured. Ecotoxicity tests were carried out to follow the detoxification capacity of the system as well as its potential for using in the treatment of this type of agroindustrial effluent.
- Kinetics of a packed-bed bacth reactor for the treatment of olive oil wastewaters from a Portuguese millPublication . Ribeiro, Belina; Correia, Anabela; Paixão, Susana M.; Baeta-Hall, Lina; Sàágua, M. C.; Duarte, José CardosoOlive oil production is a traditional agricultural industry in Mediterranean countries and Portugal is one of the ten major producers. This industry generates an effluent, olive mill wastewater. This effluent does not undergo any treatment and is usually stored in evaporation lagoons or spread on the land. This can have a negative impact in the environment since this effluent has a high level of organic matter leading to a high chemical oxygen demand. In addition it has also a high content of polyphenols that contributes to the ecotoxicity of this effluent.Different techniques for the treatment of these wastewaters have been studied. In this work a 60 litre vessel was filled with a packaging of plastic material consisting of a cubic geometry (Biological Carrier Media from Rauschert). The non-inoculated reactor was filled with effluent from an olive mill farm (from Alfândega da Fé, Trás-os-Montes) and the effluent was re-circulated daily for homogeneity. COD, colour, nitrogen, solids and phosphorous were measured to follow the evolution of the system. Microbial composition and polyphenols were also evaluated. As an indicator of the microbial activity in the reactor, lipase activities were measured. Ecotoxicity tests were carried out to follow the detoxification capacity of the system as well as its potential for using in the treatment of this type of agroindustrial effluent.
- Metals recovery from mine lead concentrates:screening of bioleaching microbial communitiesPublication . Duarte, José Cardoso; Sàágua, M. C.; Paixão, Susana M.; Baeta-Hall, Lina; Nogueira, Carlos; Pereira, Paula Sá; Anselmo, Ana
- Microflora evaluation on aerobic treatment of olive oil wastewaterPublication . Eusebio, Ana; Mateus, Marta; Baeta-Hall, Lina; Almeida-Vara, Elsa; Duarte, José Cardoso