iBB

The therapeutic use of human mesenchymal stem/stromal cells (MSC) for a wide range of diseases is at the front line of stem cell-based cellular therapies. Through a bioprocess engineering approach, researchers at BERG-iBB led by Cláudia Lobato Silva and Joaquim Cabral, were able to maximize the production of MSC from different human sources – bone marrow and adipose tissue - in a microcarrier-based stirred culture system. The advances, reported in a recent paper on Biotechnology Journal, clearly improve the scalability and cost-effectiveness of MSC manufacturing, while facilitating the translation to a Good Manufacturing Practices (GMP)-compliant bioprocess.

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Aerobic granular sludge (AGS) is a compact and energy-saving biotechnology pointed as the next generation of wastewater treatment. In a recent publication, BERG-iBB and BSRG-iBB researchers led by Nídia Lourenço compare the performance of AGS with conventional activated sludge in the treatment of textile industry wastewater. High efficiencies were attained in both systems, with AGS providing higher yields and excellent biomass settling properties. Yeast-based toxicity assays also highlighted the better wastewater detoxification performance of AGS, supporting its potential application for industrial wastewater treatment as an effective alternative to the conventional technology based on floc-forming bacteria.

Microreactors have been gaining increased relevance as preferred process intensification tools. Microreactors present several advantages over conventional batch reactors, namely mass and heat transfer, high surface to volume ratios, minute consumption of chemicals, ease of automation and better process control. Within the scope of this exciting area of research, Pedro Fernandes and Filipe Carvalho from BERG-iBB recently designed, assembled and run a low-cost continuous flow enzyme microreactor, allowing for detailed characterization of biocatalytic systems with immobilized enzymes in particulate form. Moreover, the microreactor enabled continuous enzymatic sucrose hydrolysis for 1 month, with sustained substrate conversion of roughly 100%.

Heparin is a naturally occurring sulfonated glycosaminoglycan, characterized by a high density and distribution of negative charges that is widely used as an injectable anticoagulant. In a recent pubication, BERG-iBB researchers led by Ana Azevedo explore the strong cation exchanger potential of an heparin resin, namely its  ability to capture a basic mAb from CHO cell culture supernatants. The performance of the proposed capture step was estimated in terms of yield, protein purity and purification factor, and compared to the traditional protein A affinity chromatography.

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Money is usually considered a source of infections. In a study comparing the bacterial numbers and diversity on coins collected in Casablanca and Lisbon, Carla C.C.R. de Carvalho (BERG-iBB, IST) and Maria-José Caramujo (FCUL) showed that coins transported in pockets presented higher number of bacterial isolates than coins transported in wallets, regardless of the gender of the person transporting them. The work, published in FEMS Microbiology Ecology, suggests that temperature and moisture might be key parameters for bacterial survival on metallic coins. The percentage of Staphylococcus strains was, curiously, 44% of the total isolates on both Moroccan Dirham and Euro coins. Click on title to learn more.

Researchers from BERG and Biotrend have reported for the first time the ability of Burkholderia sacchari to produce poly(3-hydroxybutyrate co-4-hydroxybutyrate) - P(3HB-co-4HB) - from xylose-rich wheat straw hydrolysates (WSH) using gamma butyrolactone (GBL) as precursor. In a joint publication in the International Journal of Biological Macromolecules, members from the two teams describe a fed-batch process that achieves high copolymer productivities (0.5 g/L.h) and 4HB incorporations (5.0 molar%) using WSH and GBL.. Due to their properties, polymers like P(3HB-co-4HB) may replace petrochemically produced bulk plastics like polyethylene and polypropylene. The fact that they are completely degradable to carbon dioxide and water through natural microbiological mineralization constitute additional advantages of PHB derivatives.

MtvR is a 136-nucleotide long sRNA previously identified in the human pathogen Burkholderia cenocepacia J2315 and with homologues restricted to bacteria of the Burkholderia cepacia complex. In a paper published in PlosOne, a team led by Jorge Leitão from BSRG show that MtvR negatively regulates the hfq mRNA levels in both bacterial species. In the case of E. coli, this negative regulation is shown to involve binding of MtvR to the 5′-UTR region of the hfqEc mRNA. Results presented also show that expression of MtvR in E. coli and P. aeruginosa originates multiple phenotypes, including reduced resistance to selected stresses, biofilm formation ability, and increased susceptibility to various antibiotics. Click on title to learn more.

In collaboration with Rensselaer Polytechnic Institute (RPI/USA), BERG researchers at the Stem Cell Bioengineering and Regenerative Medicine Laboratory (SCBL) have recently developed a 3D microarray platform to perform high-throughput studies of human Neural Stem Cell (hNSC) Differentiation and Toxicology. By using this platform it is possible to screen for the differential toxicity of small molecules to hNSCs which may help to predict, in vitro, which compounds pose an increased threat to neural development and should therefore be prioritized for further screening and evaluation. The work was published in “Stem Cell Research” journal. Click on title to learn more,

The taxonomy of Burkholderia cepacia complex (Bcc) has recently evolved significantly. The novel species B. contaminans and B. lata were proposed for a divergent group of bacteria formerly classified as B.cepacia recA K. In a recent publication in the Journal of Medical Microbiology, Carla Coutinho and Isabel Sá-Correia from BSRG-iBB, together with researchers from Hospital de Santa Maria (HSM) in Lisbon, have re-examined the taxonomic position, at the species level, of several isolates previously classified as B. cepacia recA K from a Bcc collection and also extended the identification to other isolates retrieved from CF patients under surveillance at the major Portuguese CF Center at HSM. During 15 years of epidemiological surveillance of respiratory infections involving Bcc in this Portuguese CF Center, B. contaminans was found to be involved in chronic and transient infections or to have been eradicated. The clinical outcome of the infected patients under study provided new information on the clinical impact of the rarely found B. contaminans species in CF respiratory infections. Click on tile to learn more.

In a recent publication in Biotechnology Journal researchers from the Stem Cell Bioengineering and Regenerative Medicine Laboratory (SCBL) at BERG-iBB describe a novel methodology capable of providing patient-specific neural cells under defined conditions using vitronectin and dual SMAD inhibition. The authors show how pluripotent stem cells can be used to generate patient-specific neural cells that could be used to gain a better understanding of disease mechanisms. This ability to recapitulate the development of the human nervous system in vitro could provide important insights on the mechanisms involved in the maturation of specific neural cell types, making this approach transversal to other related areas in neurodevelopmental research.

The quest for renewable fuels from sustainable and ecologically friendly processes has identified biodiesel as a promising candidate. Carla de Carvalho and Maria  Cortes of BERG-iBB recently showed that bacterial cells of Rhodococcus erythropolis DCL14 and R. opacus PWD4 can accumulate triacylglycerols, the most relevant lipids for biodiesel production, and other lipids which contain fatty acids that may be esterified. Appropriate growth conditions, such as N and P limitation, increased lipid accumulation in the cells. The cetane numbers of the fatty acid blends produced, which measure the quality of diesel fuels and biodiesel, are in accordance to biodiesel standards.

3D suspension culture is generally considered a promising method to achieve efficient expansion and controlled differentiation of human pluripotent stem cells (hPSCs). In a recent publication in Biotechnology Journal,  researchers from the Stem Cell Bioengineering and Regenerative Medicine Laboratory (SCBL) at BERG-iBB led by Margarida Diogo describe the development of an integrated culture platform for expansion and neural commitment of hPSCs into neural precursors using 3D suspension conditions and chemically-defined culture media. The results obtained in the study constitute an important contribution to the definition of a robust method for production of hPSC-derived neural precursors that minimizes processing steps and has high potential for scale-up.

The 2015 edition of the special issue Environmental Biotechnology published by Current Opinion in Biotechnology features a review on the field of yeast toxicogenomics, focusing on the role of this organism both as a cell model and as a cell factory. Toxicogenomics has emerged in the past decade as a transdisciplinary area that merges genome-wide methodologies with traditional toxicology studies to provide an integrated assessment of the cellular response to different toxicants at multiple levels. The invitation to write this review was made on the basis of the longstanding contribution of the Biological Sciences Research Group-iBB and its PI Isabel Sá-Correia to this field.
The still highly relevant role of yeast as a model organism is highlighted in this review, supported by the pioneering exploitation of multiple Omics approaches (genomics, proteomics, metabolomics, transcriptomics, lipidomics...) and synthetic biology, in fields ranging from the pharmaceutical industry to food preservation processes and identification of toxicological outcomes of exposure to environmental toxicants and agrochemicals. The review also describes the most recent advances in the production of next-generation biofuels based on renewable feedstocks such as lignocellulosic hydrolysates. Yeast is a cell factory of choice in biorefineries, where genomic and metabolic engineering are greatly contributing to develop more cost-efficient bioprocess conditions and more robust engineered strains. Click on the title to learn more.

A joint publication from BSRG-iBB and IMAR & MARE – University of Coimbra in the journal Science of the Total Environment describes evaluation of the suitability of a short-term yeast-based gene expression assay to assess the toxicity of pyrimethanil in runoff samples simulated from soils sprayed with fungicide accidental spill doses. Comparison of toxicity data to the yeast and to aquatic and soil standard species pointed the yeast assay relevant for screening worst-cases of fungicide contamination. This work was performed in the context of Fátima Gil’s PhD in Biotechnology (finished july 2014; supervisors: Cristina A Viegas, Jorge H Leitão).

Photo sources: en.wikipedia.org, www.zmescience.com, www.marietta.edu, enfo.agt.bme.hu, www.infojardin.com

In a recent paper published in Journal of Bionic Engineering, researchers from BERG-IBB studied the topography and wettability of the underside of English weed (Oxalis pes-caprae) leaves using epoxy replicas created via a two-step casting process. Leaves were found to be close to super hydrophobic due to the presence of a characteristic pattern of irregular 100 µm – 200 µm × 60 µm convex papillae. The water repellency properties of such microstructured surfaces may have important applications, including self-cleaning, anti-microbial and anti-fouling.

Photo details: SEM image of an epoxy replica of the leaf of English weed. P.M. Pereira, 2013.