Browsing by Author "La Cara, F."
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- Anaerobic digestion process for biogas and biomolecules production: microflora identification and characterizationPublication . Eusebio, Ana; Chaves, S.; Tenreiro, R.; Almeida-Vara, Elsa; Morana, A.; Ionata, E.; La Cara, F.; Marques, Isabel PaulaThe anaerobic process was efficient in organic matter removal. During the process, an interesting compound as quercetin was produced inside of reactor. Phylogenetic analysis showed the presence of phylotypes affiliated with gamma-Proteobacteria, Choroflexi, and Bacteroidetes. Archaea were represented by phylotypes belonging to the genus Methanosarcina and Methanosaeta.
- Bioactive compounds through anaerobic digestion of heterotrophic microalgae residuesPublication . Morana, A.; Squillaci, G.; Santos, Carla A.; La Cara, F.; Marques, Isabel PaulaSeveral important biomolecules are available into anaerobically digested effluents that were obtained from the biodiesel production process using heterotrophically grown microalga Chlorella protothecoides. Defatted microalgae residues and crude glycerol may undergo anaerobic digestion, separately and in admixture, providing methane/hydrogen and a digestate exploitable for agriculture applications. Furthermore, industrial interesting bioactive compounds such as polyphenols provided with antioxidant activity can be obtained. Anaerobic process offers a promising chance and can be advantageously combined with algae lipid-extraction techniques in order to make it more sustainable.
- Cork boiling wastewater anaerobic digestion process leads to biogas and valuable enzymes productionPublication . Gil, Luís; La Cara, F.; Marques, Isabel PaulaCork is the outer bark of the cork-tree (Quercus suber L.) and it is a very important industrial sector in western Mediterranean region, being Portugal the world-leading producer and exporter (1). The anaerobic digestion has never been applied to the treatment and valorization of the industrial cork effluents (cork boiling wastewater, CBW). The goal of the present work is evaluate the role of this biological process in providing valuable biomolecules, i.e. enzymes, during the conversion of CBW. Anaerobic experiments were conducted under mesophilic conditions of temperature and the obtained results suggest that CBW is an interesting substrate to be treated and valorised through the anaerobic digestion. Besides the energy recovery through biogas production by anaerobic digestion of CBW, the increase in the reactor effluent of valuable biomolecules is an aspect of great industrial interest. The identification and characterization of such products of high added value creates a supplementary prospect of effluent valorisation, contributing to the cork sector profits. During the CBW anaerobic digestion process several important alterations on the enzymatic capacity of the digested flow were observed. For instance, the laccase activity contained in the CBW was implemented by anaerobiosis and the xilanase was formed during the process. Laccases exhibit low substrate specificity and can be used in different industrial sectors (i.e. paper manufacturing, wine stabilization and wastewater treatment) (2). Xylanases are enzymes involved in the hydrolyse carbohydrates and are used in the pulp, paper and food industries (3). The production of enzymes with commercial interest offers an additional opportunity for the biotechnological valorisation of the CBW, contributing to make the process more interesting and cheaper.
- Energetic and biochemical valorization of cork boiling wastewater by anaerobic digestionPublication . Gil, Luís; La Cara, F.; Marques, Isabel PaulaIn addition to energy benefits, anaerobic digestion offers other interesting advantages. The cork industry is of great environmental, economic and social significance in the western Mediterranean region, with Portugal being the world-leading producer and exporter. Cork boiling wastewater (CBW) is a toxic and recalcitrant organic effluent produced by this sector, which constitutes a serious environmental hazard. However, there is no documented research on anaerobic treatment/valorization performed with this effluent. The work presented here was developed with the aim to use the anaerobic digestion process to convert the CBW polluting organic load into an energy carrier gas and valuable molecules for industry.
- A novel β-xylosidase from Anoxybacillus sp. 3M towards an improved agro-industrial residues saccharificationPublication . Marcolongo, L.; La Cara, F.; Del Monaco, G.; Paixão, Susana M.; Alves, Luís; Ionata, E.; Marques, Isabel PaulaABSTRACT: An intracellular β-xylosidase (AbXyl), fromthe thermoalkaline Anoxybacillus sp. 3M,was purified and characterized. The homodimeric enzyme (140 kDa) was optimally active at 65 °C and pH 5.5, exhibited half life of 10 h at 60 °C, 78 and 88% residual activity after 24 h, at pH 4.5 and 8.0, respectively. Fe2+, Cu2+, Al3+, Ag+ and Hg2+inhibited the enzyme; the activity was moderately stimulated by SDS and not influenced by β-mercaptoethanol. In the presence of p-nitrophenyl-β-D-xylopyranoside, AbXyl exhibited Km of 0.19 mM, Kcat of 453.29 s−1, KcatKm−1 of 2322 s−1mMandwas moderately influenced by xylose (Ki 21.25mM). The enzyme hydrolyzed xylo-oligomers into xylose and catalyzed transxylosilation reactions also in presence of alcohols as acceptors, producing xylo-oligosaccharides and alkyl-xylosides. Finally AbXyl was applied towards a statistically optimized process of brewery's spent grain bioconversion, highlighting the important role of this biocatalyst in reaching high yields of fermentable sugars.
- Olive mill wastewater conversion into a stream for agricultural application: anaerobic and electrochemical processesPublication . Sampaio, M. A.; La Cara, F.; Correia, J. P.; Marques, Isabel PaulaAnaerobic digestion and the electrochemical oxidation were used to valorise the effluent of the olive oil production (olive mill wastewater, OMW). Anaerobiosis was realized in an anerobic hybrid reactor, operating at a low hydraulic retention time of about 6 days and digesting the raw OMW, without any previous substrate altarations. Electrochemical process worked with a dimensionally stable anode (DSA), without adding further support electrolytes, at low potential values and at moderate dulution factor of the substrate.
- Phenolic compouds with antiradical activity from the cork boiling wastewater anaerobic digestionPublication . Gil, Luís; La Cara, F.; Marques, Isabel PaulaThis work aims to develop a procedure that explores the different types of valorization that can be obtained by integrating a biological process, such as the anaerobic digestion, to promote the bioconversion of the industrial cork effluents (cork boiling wastewater, CBW).
- Phenolic waste valorization through bioenergy and bioactive compounds production [Resumo]Publication . Morana, A.; La Cara, F.; Marques, Isabel PaulaThe agricultural and industrial processing activities produce large amounts of waste that are only partially valorised at different value-added levels (spread on land, animal feed, composting), whereas the main volumes are managed as waste of environmental worry. These by-products are rich sources of bioactive compounds, including phenolic compounds with high antioxidant activity.
- Properties of an alkali-thermo stable xylanase from Geobacillus thermodenitrificans A333 and applicability in xylooligosaccharides generationPublication . Marcolongo, L.; La Cara, F.; Morana, A.; Di Salle, A.; Del Monaco, G.; Paixão, Susana M.; Alves, Luís; Ionata, E.An extracellular thermo-alkali-stable and cellulase-free xylanase from Geobacillus thermodenitrificans A333 was purified to homogeneity by ion exchange and size exclusion chromatography. Its molecular mass was 44 kDa as estimated in native and denaturing conditions by gel filtration and SDS-PAGE analysis, respectively. The xylanase (GtXyn) exhibited maximum activity at 70 °C and pH 7.5. It was stable over broad ranges of temperature and pH retaining 88 % of activity at 60 °C and up to 97 % in the pH range 7.5–10.0 after 24 h. Moreover, the enzyme was active up to 3.0 M sodium chloride concentration, exhibiting at that value 70 % residual activity after 1 h. The presence of other metal ions did not affect the activity with the sole exceptions of K+ that showed a stimulating effect, and Fe2+, Co2+ and Hg2+, which inhibited the enzyme. The xylanase was activated by non-ionic surfactants and was stable in organic solvents remaining fully active over 24 h of incubation in 40 % ethanol at 25 °C. Furthermore, the enzyme was resistant to most of the neutral and alkaline proteases tested. The enzyme was active only on xylan, showing no marked preference towards xylans from different origins. The hydrolysis of beechwood xylan and agriculture-based biomass materials yielded xylooligosaccharides with a polymerization degree ranging from 2 to 6 units and xylobiose and xylotriose as main products. These properties indicate G. thermodenitrificans A333 xylanase as a promising candidate for several biotechnological applications, such as xylooligosaccharides preparation.
- Valorization of chestnut manufacture process residues [Poster]Publication . Morana, A.; Laratta, B.; Vella, F. M.; Santos, Carla A.; Del Monaco, G.; La Cara, F.; Marques, Isabel Paula