iBB

Monoclonal antibodies are becoming a leading class of biopharmaceuticals but to increase their accessibility to the general population, new production processes must be developed in particular for the downstream processing. In this publication, researchers from BERG-iBB (Ana Azevedo and Raquel Aires-Barros) in collaboration with the biotechnology companies Biomedal S.L. (Seville, Spain) and ChiPro GmbH (Bremen, Germany) propose an alternative and innovative affinity chromatographic purification method using quaternary amine anion-exchange matrices. Separation is driven by the dual affinity ligand LYTAG-Z, composed of a choline binding polypeptide (LYTAG) and the synthetic antibody binding Z domain. Click on title to learn more.

Biocatalysis has widened its scope and relevance with the availability of new molecular tools, e.g. improved expression systems, protein and metabolic engineering, and rational immobilization techniques. However, applications are still hampered by low productivity and scale-up difficulties. A practical step to improve biocatalyst (enzymes, whole-cells) performance is to use flow reactors. In a recent review published in Trends in Biotechnology, Pedro Fernandes from BERG-iBB together with colleagues from the Universities of Milan and Nottingham describe the state of the art on the design and use of biocatalysis in flow reactors. The successes of the technology, new opportunities, problems and advances are critically discussed. Click on title to learn more.

Description: Aerobic granular sludge bioreactors operating at laboratory scale pictured under stage-like illumination, featured photo by Nídia Lourenço, Copyright BERG-iBB 2017.

Protein:DNA supramolecular complexes are at the heart of many molecular diagnostic systems. In a paper just published in Physical Chemistry Chemical Physics, Ana Rosa and Miguel Prazeres from BERG-iBB and Pedro Paulo from CQE present a fluorescence correlation spectroscopy (FCS) study of the complexation of oligonucleotides, antibodies and a chimeric protein of IgG-binding ZZ domains fused with a carbohydrate binding module. The FCS-derived information obtained (diffusion coefficients, association constants, nanometer-scale size of complexes) is useful to gain insight into molecular interactions involved in diagnostic assays. Click on title to learn more.

The use of engineered nanoparticles (NPs) in the textile and other industrial sectors has been rapidly increasing and their occurrence in wastewater is expected to rise accordingly. However, the fate of NPs during biological wastewater treatment is largely unknown. A recent study led by Nídia Lourenço from BERG-iBB highlighted the potential application of nuclear microscopy to characterize the interaction of silver-NPs (AgNPs) with biological wastewater treatment systems based on aerobic granular sludge (AGS). Elemental maps of AGS samples revealed that the AgNPs were preferentially associated to extracellular polymeric substances, which represents an important step forward regarding their effective removal from textile wastewater.

Oil-in-water miniemulsions display potential for application as a “green” system in the enzymatic alkyl ester synthesis. BERG-iBB researchers led by Luís Fonseca combined miniemulsion systems with medium engineering to increase the yields and produtivity of the cutinase-catalysed synthesis of medium-chain alkyl esters. Enzyme stability and reutilization were tuned by operating in a fed-batch mode, which allowed long-term utilization of the free enzyme. Click on title to learn more.

Photo details: 3D structure of cutinase from F. Solani pisi with catalytic triad in blue (PDB code: 1AGY).

The use of microscale set-ups for the fast development of bioprocesses has been gaining momentum. Within this, continuous flow operation for enzymatic reaction is particularly appealing, as it allows for steady state and ease of automation. In a paper recently published in the journal Catalysts, Pedro Fernandes and Filipe Carvalho from BERG-iBB, together with Marco Marques from UCL, presented a prototype of a home-made, easy to assemble capillary enzymatic microreactor. The assembly of the device only required materials commonly found in research labs, proved to be reproducible and reliable, and allowed for the detailed characterization of the model reaction system chosen, the production of invert syrup from sucrose. It is foreseen that the device can be easily adapted to other reaction systems and thus further disseminate the use of miniaturized set-ups for bioprocess development. Click on title to learn more.