Extraction of pigments from microalgae and cyanobacteria - A review on current methodologies

Pigments from microalgae and cyanobacteria have attracted great interest for industrial applications due to their bioactive potential and their natural product attributes. These pigments are usually sold as extracts, to overcome purification costs. The extraction of these compounds is based on cell disruption methodologies and chemical solubility of compounds. Different cell disruption methodologies have been used for pigment extraction, such as sonication, homogenization, high-pressure, CO2 supercritical fluid extraction, enzymatic extraction, and some other promising extraction methodologies such as ohmic heating and electric pulse technologies. The biggest constrain on pigment bioprocessing comes from the installation and operation costs; thus, fundamental and applied research are still needed to overcome such constrains and give the microalgae and cyanobacteria industry an opportunity in the world market. In this review, the main extraction methodologies will be discussed, taking into account the advantages and disadvantages for each kind of pigment, type of organism, cost, and final market.Foundation for Science and Technology (FCT, Portugal) under the auspices of Operational Program Human Capital (POCH), supported by the European Social Fund and Portuguese funds (MECTES); as well as by the national funds through FCT within the scope of UIDB/04423/2020, UIDP/04423/2020 and UIDB/04469/2020info:eu-repo/semantics/publishedVersio

Antimicrobial activity of endophytic fungi from olive tree leaves

In this study, the antimicrobial potential of three fungal endophytes from leaves of Olea europaea L. was evaluated and the host plant extract effect in the antimicrobial activity was examined. The volatile compounds produced by endophytes were identified by GC/MS and further correlated with the antimicrobial activity. In potato dextrose agar, both Penicillium commune and Penicillium canescens were the most effective inhibiting Gram-positive and -negative bacteria (up to 2.7-fold compared to 30 µg/mL chloramphenicol), whereas Alternaria alternata was most effective inhibiting yeasts (up to 8.0-fold compared to 25 μg/mL fluconazole). The presence of aqueous leaf extract in culture medium showed to induce or repress the antimicrobial activity, depending on the endophytic species. In the next step, various organic extracts from both A. alternata mycelium and cultured broth we re prepared; being ethyl acetate extracts displayed the widest spectrum of anti-microorganisms at a minimum inhibitory concentration ≤0.095 mg/mL. The volatile composition of the fungi that displayed the highest (A. alternata) and the lowest (P. canescens) antimicrobial activity against yeasts revealed the presence of six volatiles, being the most abundant components (3-methyl-1-butanol and phenylethyl alcohol) ascribed with antimicrobial potentialities. Overall the results highlighted for the first time the antimicrobial potential of endophytic fungi from O. europaea and the possibility to be exploited for their antimicrobial agents. Graphical Abstract: [Figure not available: see fulltext.]This work is funded by FEDER funds through COMPETE (Programa Operacional Factores de Competitividade) and by national funds by FCT (Fundação para a Ciência e a Tecnologia) in the framework of the project “EndoBio—Isolation and screening of endophytic fungi for biological control of olive against Colletotrichum acutatum and Verticillium dahliae” (PTDC/ AGR-PRO/4354/2012).info:eu-repo/semantics/publishedVersio

Sustainable extraction of biocompounds from the green seaweed ulvarigida using ohmic heating

The development of new green and sustainable extraction technologies with low environmental impact and providing high nutritional functionalities, safety and applicability, has become relevant. Ohmic heating (OH) has emerged as a novel electric-based technology which allows high heating rates, higher selectivity of interest compounds, less energy and solvent consumption and energetically more efficient.[1,2] Ulva rigida is a green seaweed with high exploitation potential for commercial application. Its major compound of interest is ulvan, a sulfated polysaccharide present in the cell wall that has a wide range of possible applications in nutraceuticals, functional foods, agriculture and biomaterials.[3] The aim of this work was to access the feasibility of OH assisted extraction as an alternative extraction technology in the recovery of biocompounds (e.g.: polysaccharides, proteins, phenolic compounds and pigments) from Ulva rigida using different ratios of water/ethanol in different times of extraction. Extractions were made using a solid:solvent ratio of 1:30 and water/ethanol mixtures ranging from 0 to 75 % ethanol to extract different seaweeds fractions. The extractions were performed at 82 °C during 1 h, 2 h and 3 h, and the frequency was set at 25 kHz. Control extractions were made using a water bath (conventional extraction) with the same conditions, but without the presence of an electric field. Different parameters were assessed including extraction yield, lipids, ashes, moisture, total polysaccharides, protein, total phenolic compounds and pigments (chlorophylls and carotenoids) content, antioxidant activity and gelling ability. Higher extraction and ulvan-fraction yields, as well as total polysaccharides were obtained after 3 h of extraction for aqueous extracts. Total phenolic compounds, proteins and pigments content and antioxidant activity were higher for mixtures with higher amounts of ethanol. For antioxidant activity and total phenolic compounds, the 50:50 H2O/EtOH mixture under OH proved to be more efficient, with an increase up to 10 %, when compared to conventional extraction. Also, for pigments and protein content, the 25:75 H2O/EtOH mixture allowed promising results for 1 h of extraction. Gelling ability was identical in all produced extracts. As conclusion, these results showed that OH is a good alternative for a low cost and environmental-friendly extraction technology, for the recovery of bioactive compounds from green seaweeds.info:eu-repo/semantics/publishedVersio

Interaction between two co-occurring fungi present in chestnut orchards

Hypholoma fasciculare is a wood-decaying basidiomycete with a worldwide distribution, including tropical, temperate and boreal forest ecosystems. In Trás-os-Montes region (Northeast of Portugal) this species is commonly present in soils of several habitats, including chestnut and oak tree forests. The ectomycorrhizal fungus Pisolithus tinctorius is another species with high occurrence in those ecosystems. The present work intends to study the in vitro interaction between H. fasciculare and P. tinctorius through evaluation of fungal growth, changes on hyphae morphology, the production of volatile compounds and Iytic enzymes. The results obtained showed that H. fasciculare inhibited significantly the growth of P. tinctorius in 49%, long before hyphal contact of their colonies. This inhibition could be result from the liberation from H. fasciculare of volatile compounds and/or diffusible inhibitory substances, such as extracellular enzymes. Alteration in the production of volatile compounds, distributed in several chemical classes (alcohols, ketones, aldehydes, terpenes, among others) was detected over the time course of interaction. In addition, amylase, cellulase, laccase and lipase were produced by H. fasciculare. The possible role of these compounds during interaction will be discussed.This work is supported by FCT I&D grant PTDC/ AGR-AAM/099556/200

Pigments extraction from Cyanobium sp. a comparison between pressure-based and electric fields-based technologies

Pigments from cyanobacteria, in special carotenoids and phycobiliproteins, have been seen with considerable interest for industrial applications due to their bioactive properties and their natural product characteristics. The extraction of these compounds is focused on the methodologies of cell disruption and on the chemical solubility of the compounds. In this study, two different methods were optimised and evaluated in terms of pigments´ extraction from the marine cyanobacterium Cyanobium sp.: a continuous pressurized solvent extraction (CPSE) system, and an electric fields-assisted extraction system based in ohmic heating (OH). For each method, a Central Composite Design (23) was performed. Optimal conditions for each extraction method were then compared to determine the best method for the extraction of pigments from Cyanobium sp. In both optimisation and comparison steps, two extracts were obtained from the same biomass: an ethanolic extract (carotenoids-targeted) and a successive water extract (phycobiliproteins-targeted). The content and profile of carotenoids and phycobiliproteins and the respective antioxidant capacity of extracts were evaluated. OH provided the best ethanolic extract, with a carotenoids content of 41.6 ± 1.7 mg gDW-1, and total antioxidant capacity of 8.0 ± 0.3 mgTE gDW-1, representing an increase of 1.3-fold and 2.5-fold respectively, when compared to CPSE. Regarding the aqueous extract, both methods led to the same content of phycobiliprotein (135 ± 10.0 mg gDW-1), although OH led to an antioxidant capacity of this extract of 8.3 ± 0.3 mgTE gDW-1, 3.6-fold higher when compared to CPSE. In terms of profile, no major variation was found between extraction methods, being lutein, zeaxanthin, echinenone and -carotene the major carotenoids (>60 % of total carotenoids), and phycocyanin and allophycocyanin the only present phycobiliproteins (in a 1:2 ratio). In addition to the productivity and composition of the extracts, the design and applicability of the system must be considered. Once again, OH overtook the other methods due to the scalability and possible continuous operation. Overall, OH proved to be the best of the two methodologies for pigments co-extraction from Cyanobium sp..A PhD fellowship (reference SFRH/BD/136767/2018) for author Fernando Pagels was granted by Fundação para a Ciência e Tecnologia (FCT, Portugal) under the auspices of Programa Operacional Capital Humano (POCH), supported by the European Social Fund and Portuguese funds (MECTES). This work was financially co-supported by the strategical funding from FCT UIDB/04423/2020, UIDP/04423/2020 and UIDB/04469/2020; and the project ALGAVALOR – MicroALGAs: produção integrada e VALORização da biomassa e das suas diversas aplicações (POCI-01-0247-FEDER-035234), supported by the European Regional Development Fund and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Bovine grafting : an effective alternative after curettage of benign bone tumors

We retrospectively reviewed 28 patients (15 women and 13 men) with benign bone tumors or pseudotumors treated with curettage and filling with freeze-dried bovine bone graft Orthogen (Baumer S/A, São Paulo, Brazil). The aim of the study was to evaluate the rate of incorporation of Orthogen into the host bone, as well as to describe the outcomes of bone healing (quality, time, and complications). General characteristics, tumor volume, size, site, complications, percent filled, and healing quality at 6 and 12 months were assessed through radiographs. Mean patient age was 20.5 (range 4.7-75.1) years. The most common lesion type was simple bone cyst (12/28), and the most common sites were the tibia (7/28) and humerus (7/28). There were no postoperative pathologic fractures. Two cases (7.1%) of serous fluid leakage through the wound occurred. Mean cavity volume was 20.1 (range 2.7-101.4) cm3. At 6 and 12 months, 75% and 77.8% of cavities, respectively, showed complete bone healing. At 12 months, 81% of cavities filled >90% with graft showed complete bone healing vs. only 19% of those filled <90%. Filling with bovine bone graft resulted in few complications and excellent healing after curettage of benign bone tumors or pseudotumors. Complete healing occurred in most cases by 12 months. Cavities with a higher percentage of filling had a higher rate of complete radiographic incorporation

Finite Element Modal Analysis of Transient Water Flow in Aquifers

In this paper a modal superposition method is applied for the numerical modeling of aquifers. The proximity of aquifers to populated regions requires special care in their management to avoid problems that affect the quantity and quality of the water they supply. To contribute to the management of this type of natural resource, we propose a numerical strategy based on modal analysis using the finite element method. This procedure assist water production scenarios, performing the mass balance where water extraction is done through wells, in aquifers that are subject to natural recharge. This mathematical procedure is based on the modal superposition for transient flow in porous media. To evaluate its efficiency, this strategy was compared with the classical finite element method. The advantage of the proposed method resides in the possibility of reusing the properties of the global matrix of the finite element method in transient problems, for different production conditions given by the distributed recharge and by the water extraction rate from the wells, solving the numerical problem with a more efficient use of computational resources. This strategy is useful in studies of uncertainty quantification, history matching and optimization of water production in aquifers, since these types of analysis are resource intensive for the very large number of numerical simulations required for these scenarios

GORDA: an open architecture for database replication

Database replication has been a common feature in database management systems (DBMSs) for a long time. In particular, asynchronous or lazy propagation of updates provides a simple yet efficient way of increasing performance and data availability and is widely available across the DBMS product spectrum. High end systems additionally offer sophisticated conflict resolution and data propagation options as well as, synchronous replication based on distributed locking and two-phase commit protocols. This paper presents GORDA architecture and programming interface (GAPI), that enables different replication strategies to be implemented once and deployed in multiple DBMSs. This is achieved by proposing a reflective interface to transaction processing instead of relying on-client interfaces or ad-hoc server extensions. The proposed approach is thus cost-effective, in enabling reuse of replication protocols or components in multiple DBMSs, as well as potentially efficient, as it allows close coupling with DBMS internals.(undefined

Thermal performance and comfort conditions analysis of a vernacular Palafitic timber building in Portuguese Coastline context

The palafitic timber constructions of the central Portuguese coastline are an example of the adaptation to site-specific conditions (climate and sand landscape morphodynamics) using the available endogenous resources. Thus, in a context of environmental awareness and climate change, it is relevant to understand their features/strategies and how they perform. This work analyses the energy performance and thermal condition evaluation of a vernacular timber building–palheiro–from Praia de Mira, through in situ measurements, subjective analysis and energy simulation provided by DesignBuilder/EnergyPlus. The results show a good or satisfactory thermal performance during most of the seasons by passive means only. Despite, it was not possible to guarantee thermal comfort conditions for the occupants during winter. In the energy performance analysis, five scenarios, with different external walls, were compared. In the two scenarios that satisfy the maximum U-value for the climate zone, the current conventional building had a slightly better performance on heating and cooling (less 1.1 and 1.4 kWh/m2, respectively) than the timber building. However, the difference between the two construction solutions is not substantial in the annual energy demand (2.5 kWh/m2, 7.3%), indicating that timber structures are suitable in this mild climate area.POCI-01-0145-FEDER-029328; PD/BD/113641/2015. FEDER funds through the Competitively and Internationalization Operational Programme (POCI) and by national funds through FCT (Foundation for Science and Technology) within the scope of the project with the reference POCI-01-0145-FEDER-029328 and of the PhD grant with the reference PD/BD/113641/2015, that were fundamental for the development of this stud