Papers by Rui M F Bezerra
Com o objectivo de se conhecer a influência e as interacções entre três complexos enzimáticos (Ce... more Com o objectivo de se conhecer a influência e as interacções entre três complexos enzimáticos (Celulases, β-glucosidase e Xilanase) e a quantidade de sólidos a hidrolisar procedeu-se a um ensaio, utilizando como a matéria-prima resíduos das podas do olival, com granulometria inferior a 0,850 mm (80mesh), sem qualquer tipo de pré-tratamento químico. O delineamento experimental deste ensaio foi realizado no programa de análise estatística “Design Expert 7 Trial Version” utilizando a metodologia de superfície de resposta (Surface Response) com análise central composta. O ensaio foi realizado sobre a biomassa, num volume reaccional de 50ml, utilizando uma solução tampão citrato 0,05M a pH 4,8. A quantificação de açucares redutores após a reacção hidrolítica foi realizada pelo do método do DNS às 42h e 139h de reacção. O modelo de estimativa para libertação de açúcares, em função dos teores de celulase (A), β-glucosidase (B), xilanase (C) e sólidos (D), apresentou valores de R2 de 0,9552...
Produção e quantificação de polissacáridos intracelulares de Ganoderma resinaceum, Phlebia rufa e Trametes versicolor e avaliação da sua acção na viabilidade e crescimento de células HepG2
Produção e quantificação de polissacáridos intracelulares de Ganoderma resinaceum, Phlebia rufa e Trametes versicolor e avaliação da sua acção na viabilidade e crescimento de células HepG2
Chemosphere, 2019
h i g h l i g h t s White-rot fungi present high variability in respect to vinasse pollution abat... more h i g h l i g h t s White-rot fungi present high variability in respect to vinasse pollution abatement. Threefold fungal biomass increase due to degradation and uptake of vinasse compounds. Phenolics, TOC and vinasse color were significantly reduced throughout P. rufa biodegradation. Acute toxicity of treated vinasse decreased for A. fischeri and D. magna (75%). P. rufa almost completely eliminated vinasse phytotoxicity.
Ecotoxicology and Environmental Safety, 2019
Vinasses obtained from the distillation of winemaking by-products (WDV) are complex effluents wit... more Vinasses obtained from the distillation of winemaking by-products (WDV) are complex effluents with variable physicochemical properties. Frequently, WDVs are used to irrigate agricultural soil, and/or discharged into aquatic bodies, which may result in serious environmental pollution, due to the presence of organic acids and recalcitrant compounds (polyphenols, tannins and metals). The present study aimed to evaluate the toxicity impact of an untreated WDV on terrestrial and aquatic organisms, at different levels of biological organization. The effluent was collected at the distillation column exit and characterized according to several physicochemical properties. The WDV potential phytotoxicity was assessed by germination inhibition assays on six agricultural crops, and its acute toxicity was assessed on Aliivibrio fisheri (microtox assay), Daphnia magna neonates (freshwater crustacean), and zebrafish Danio rerio (fish embryo toxicity test, FET). The WDV presented a low pH (3.88), high levels of electrical conductivity, ECond (6.36 dS m −1) and salinity (3.3 ppt), besides high level of potassium (2.1 g L −1) and organic compounds (TOC = 17.7 g L −1), namely polyphenols (1.7 g L −1). The diluted WDV displayed variable inhibitory effects on the plant endpoints (percentage of inhibition of germination and radicle elongation and germination index). Overall, plants' susceptibility to increasing concentrations of WDV were differential (onion ≈ garden cress ≥ tomato > lettuce > maize > green beans) and the germination index EC 50 varied from 10.9 to 64.4% v/v. Also, the acute negative effects toward aquatic organisms were determined, decreasing from the more complex organism to the simpler one: zebrafish embryos (96 h-LC 50 = 0.34% v/v) > D. magna (48 h-LC 50 = 4.8% v/v) > A. fisheri (30min-EC 50 = 7.0% v/v). In conclusion, the findings suggest that WDVs might have a high toxicological impact on both terrestrial plants and aquatic organisms, even at high dilution levels, reinforcing the need for appropriate treatments before considering its discharge or reuse.
Selection, engineering, and expression of microbial enzymes
Enzymes in Human and Animal Nutrition, 2018
Abstract Native and recombinant enzymes are tools in major sectors of the biopharmaceutical, agri... more Abstract Native and recombinant enzymes are tools in major sectors of the biopharmaceutical, agricultural, and chemical industries, acting in very diverse areas of medicine, diagnostics, food, feed, detergents, textiles, leather, paper, pulp, and plastics. Nowadays, microorganisms are the main source of commercial enzymes and are continuously optimized by selection, recombination, expression, and production of hydrolases for practical use. Biotechnology (genetic engineering) has the more accurate available methods for the optimization of enzyme production, starting from the transfer of the encoding genetic sequence from a plant, animal, or microorganism to the expressing microbe, yeast, or fungi. The safety of the source organism is the fundamental element to be taken into account in the evaluation of a target as an enzymatic source. Success with DNA polymerase has allowed an extensive increase in biotechnological utilization of enzymes from archaea (extremozymes). The diversity of proteins from extremophiles allows the expansion of the ranges of optimal enzyme general hydrolytic performance as well as enables enzymatic biocatalysis under unfavorable conditions. Priorities in the screening and development of improved and/or new enzymes are detergents, drugs, bioremediation, waste treatment, and valorization of nonedible plant biomass. The use of enzymes in “white biotechnology” is expected to grow to over 8 million metric tons in 2018. The initial process of enzyme discovery and optimization is still a limiting factor in the adoption of new biobased industrial processes. There is therefore an increasing opportunity to promote newly discovered archaeal enzymes for sustainable manufacturing. Techniques to achieve such goals are metagenomic and metatranscriptomics-based approaches, high-throughput screening, genetic engineering, and ideal expression organisms.
International Journal of Environmental Research and Public Health, 2020
Grape stalks, an inedible lignocellulosic residue from winemaking and agro-industrial grape juice... more Grape stalks, an inedible lignocellulosic residue from winemaking and agro-industrial grape juice production, can be valorized as a source of bioactive compounds and as feedstock for the saccharification and bioconversion of soluble sugars. Solid-state fermentation (SSF) by six white-rot fungi was applied as pretreatment. Fiber composition, free radical scavenging activity, four ligninolytic, and three hydrolytic enzyme activities were determined. Saccharification kinetics, yield, and productivity were evaluated and complemented with scanning electron microscopy (SEM), high performance liquid chromatography (HPLC) quantification of monosaccharides, and principal component analysis (PCA). After SSF, the biomass exhibited a drastic free radical scavenging activity decrease and the main enzymes produced were manganese-dependent peroxidase and xylanase. Scanning electron microscopy revealed the erosion of cell walls, and PCA exhibited a negative correlation between saccharification, and...
Characterization of Acid Treatment in Olive Tree Pruning
ABSTRACT
Determinação das interacções entre complexos enzimáticos resultantes da hidrólise de resíduos das podas do olival
Com o objectivo de se conhecer a influência e as interacções entre três complexos enzimáticos (Ce... more Com o objectivo de se conhecer a influência e as interacções entre três complexos enzimáticos (Celulases, β-glucosidase e Xilanase) e a quantidade de sólidos a hidrolisar procedeu-se a um ensaio, utilizando como a matéria-prima resíduos das podas do olival, com granulometria inferior a 0,850 mm (80mesh), sem qualquer tipo de pré-tratamento químico. O delineamento experimental deste ensaio foi realizado no programa de análise estatística “Design Expert 7 Trial Version” utilizando a metodologia de superfície de resposta (Surface Response) com análise central composta. O ensaio foi realizado sobre a biomassa, num volume reaccional de 50ml, utilizando uma solução tampão citrato 0,05M a pH 4,8. A quantificação de açucares redutores após a reacção hidrolítica foi realizada pelo do método do DNS às 42h e 139h de reacção. O modelo de estimativa para libertação de açúcares, em função dos teores de celulase (A), β-glucosidase (B), xilanase (C) e sólidos (D), apresentou valores de R2 de 0,9552...
Effect of slurry application and its acidification or injection on soil biochemistry indicators in an ongoing field trial
ABSTRACT Injection of slurry and band application of acidified slurry are considered alternative ... more ABSTRACT Injection of slurry and band application of acidified slurry are considered alternative efficient solutions to minimize ammonia emissions during and after slurry application to soil. The aim of the present work was to assess the effect of those alternatives relative to traditional slurry broadcast and mineral N application on soil quality indicators, assuming that soil management may impact on the microbial processes over a shorter time scale.
Effect of cattle slurry amendment on soil enzymatic activity: impact of slurry treatment and application method
ABSTRACT
Trivial nomenclature of gluco-hexose in Portuguese language and other Latin based languages
Scientific research and essays
Portuguese is ranked seventh among the world's languages in number of native speakers (o... more Portuguese is ranked seventh among the world's languages in number of native speakers (over 200 million) and the universe of all Latin daughter languages is over 700 million people (eg Spanish, French, Italian and Romanian). There is confusion in Portuguese ...
Efeito da acidificação de chorume na actividade enzimática e no potencial de nitrificação no solo (Effect of slurry acidification on enzymatic activities and nitrification potential in soil)
Animal slurry is commonly used in soils as an organic amendment but its superficial application w... more Animal slurry is commonly used in soils as an organic amendment but its superficial application without led to significant ammonia emissions. To avoid such emissions, injection or slurry acidification can be performed prior to soil application but the global effect of such practice in terms of enzymatic activities and N cycling is still unclear, namely the acidification option. The aim of the present work was to assess the impact of acidified slurry application to soil on enzyme activity (one endoenzyme and one exoenzyme) and on nitrification potential of soils over three cycles of slurry application.
Effect of slurry acidification on enzymatic activities and nitrification potential in soil
Effect of Organic Residues on the Enzyme Activity in Soils
ABSTRACT Organic farming tends to promote soil health through the use of cover crops, crop residu... more ABSTRACT Organic farming tends to promote soil health through the use of cover crops, crop residues and organic fertilizers and amendments, since incorporation of organic materials in soil increases microbial and enzyme activity. Derived either from microorganisms, its main source, as from plant roots and soil animals, soil enzymes mediate biochemical reactions related to nutrient cycling and essential for nutriente provision to crops, especially in conditions when no mineral nutrient sources are utilized.
Chemosphere, 2014
h i g h l i g h t s First report on WW treatment by two basidiomycetous yeasts followed by Fenton... more h i g h l i g h t s First report on WW treatment by two basidiomycetous yeasts followed by Fenton's reagent. Both yeasts had identical pollution abatement performances but C. laurentii was faster. H 2 O 2 concentration was critical in COD and TPP removal. WW treated by biological and Fenton reagent is within legal limits for released in natural waters.
Decolorization of Azo Dyes by Yeasts
The Handbook of Environmental Chemistry, 2010
Azo dyes are synthetically produced organic molecules and represent the largest group of commerci... more Azo dyes are synthetically produced organic molecules and represent the largest group of commercial dyes. Industrial use for coloring purposes generates huge volumes of dyed effluents, which are of environmental concern. Color removal has been achieved by using ...
World Journal of Microbiology and Biotechnology, 2003
Bioremediation is considered a promising eco-efficient alternative for industrial wastewater trea... more Bioremediation is considered a promising eco-efficient alternative for industrial wastewater treatment. Particular attention is currently being given to biological degradation of synthetic dyes and more specifically to colour removal by fungi. This work looks at the extracellular enzymatic system of strain Euc-1. Its ability to decolourize 14 xenobiotic azo dyes was evaluated and compared with the well-known species Phanerochaete chrysosporium. Strain Euc-1 is a mesophilic white-rot basidiomycete, the main secreted ligninolytic enzyme being laccase (0.38 U ml)1). Although low manganese-dependent peroxidase activity (0.05 U ml)1) was also detected, neither lignin peroxidase nor aryl alcohol oxidase could be found in batch culture. Optimum pH values of 4.0 and 5.0 were obtained in the laccase-catalysed oxidation of guaiacol and syringaldazine, respectively. Laccase activity increased with the temperature rise up to 50-60°C and remarkable thermal stability was observed at 50°C with a half-life of 12 h and no deactivation within the first 2 h. Solid-plate decolourization studies showed that basidiomycete Euc-1 decolourized 11 azo dyes whereas P. chrysosporium only two. Moreover, it is shown that purified laccase from basidiomycete Euc-1 efficiently decolourizes the azo dye acid red 88.
Screening of fungal isolates and properties of Ganoderma applanatum intended for olive mill wastewater decolourization and dephenolization
Letters in Applied Microbiology, 2007
To investigate different autochthonous isolates of wood-rotting fungi for the removal of both col... more To investigate different autochthonous isolates of wood-rotting fungi for the removal of both colour and phenolic compounds from olive mill wastewaters (OMW). The isolates Bjerkandera adusta Ba-100, Fomes fomentarius Ff-106, Ganoderma applanatum Ga-20, Irpex lacteus Il-3, Trametes versicolor Tv-101 and Tv-103 were preliminarily screened for their OMW-decolourizing potential on potato dextrose agar supplemented with different OMW concentrations. A further screening of batch cultures under different agitation speeds, to test the effect of shear stress, resulted in the selection of isolate G. applanatum Ga-20. Batch cultures grown in OMW-based medium exhibited strong laccase induction and significant decrease in the values of phenols, colour and chemical oxygen demand. Concomitant onset of laccase activity and colour removal was observed, and apart from laccase, neither lignin peroxidase nor manganese-dependent peroxidase activities were detected. Moreover, the depletion of aromatic compounds with high and low apparent molecular mass was observed by chromatographic analysis. Isolate G. applanatum Ga-20 exhibited interesting properties for its use in bioremediation of OMW, namely high removal of recalcitrant phenolic compounds and strong colour abatement. For the first time, the white-rot fungus G. applanatum proves to be effective for the decolourization and dephenolization of OMW.
Gallic acid photochemical oxidation as a model compound of winery wastewaters
Journal of Environmental Science and Health, Part A, 2008
Winery wastewaters (WW) are characterized by their high organic load and by the presence of non-b... more Winery wastewaters (WW) are characterized by their high organic load and by the presence of non-biodegradable compounds such as phenolic compounds. This study was undertaken to evaluate the capacity of different Advanced Oxidation Processes (AOP) combined with several radiation sources to degrade the phenolic compound Gallic Acid (GA). A toxicological assessment was also carried out to evaluate the subproduct's harmful effect generated during the most efficient AOP in the GA photoxidation. Through the course of the study it was verified that the UV radiation lamp TNN 15/32 showed the capacity to degrade 34.7% of GA, the UV radiation lamp TQ 150 achieved a value of 20.2% and the solar radiation presented only a value of 2.3% in 60 minutes. The combination of different advanced oxidation processes (Fenton's reagent, ferrioxalate and heterogeneous photocatalysis) were evaluated with the previously studied sources of radiation. From the experiments conducted it was possible to suggest that the AOP in combination with Fe(2 +) + H(2)O(2) + UV TNN 15/32 (photo-Fenton process) was the most efficient process thereby achieving the GA degradation value of 95.6% in 7.5 minutes and resulting in a total elimination of toxicity.
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Papers by Rui M F Bezerra