Leisch H.,NRC Biotechnology Research Institute |
Morley K.,NRC Biotechnology Research Institute |
Lau P.C.K.,NRC Biotechnology Research Institute |
Lau P.C.K.,McGill University
Chemical Reviews | Year: 2011
The monooxygenase catalyzed Baeyer-Villiger oxidation of linear or cyclic ketones as a green chemistry tool to address environmental sustainability is studied. The case of abnormal lactones in the biotransformation using bicyclo[3.2.0]hept-2-en-6-one shows that the requirement for single enantiopure compounds in drug synthesis is in increasing demand. Kayser and Stewart scheme has advanced the idea of producing the Acinetobacter cyclohexanone monooxygenase (CHMO) in a dry yeast form to make the bioreagent more user-friendly for chemists, although biocatalytic reactions can be conducted quite readily in a chemical laboratory without specialized equipment. If the mechanism of substrate and product inhibition is unknown, several rounds of error prone PCR may first be required, followed by generation and screening of focused libraries based on hits from the initial screens. A potential Baeyer-Villiger monooxygenase (BVMO) is postulated to be responsible for the lactonization of a macrocyclic compound, zearalenone.
Mena J.A.,NRC Biotechnology Research Institute |
Kamen A.A.,NRC Biotechnology Research Institute
Expert Review of Vaccines | Year: 2011
Baculovirus and insect cell culture technologies have mostly been limited to research laboratories for the transient expression of target proteins for drug development purposes. With the renaissance of the vaccine field and the regulatory acceptance of recombinant DNA technology, the baculovirus expression system has been more broadly adopted for the development of subunit vaccines, including virus-like particles. In the numerous clinical trials extensively discussed and cross-referenced in this article, product quality, safety and efficacy have been demonstrated for many candidate vaccines targeting infectious diseases. The 2007 market authorization of Cervarix™, a bivalent human papillomavirus virus-like particle vaccine against cervical cancer, was a critical milestone for the regulatory acceptance of insect cell technology in manufacturing human vaccines, opening the door to the approval of more baculovirus-derived vaccines. Insect cell technology is now a dominant platform for veterinary vaccines. This article covers the application of recombinant baculovirus as vectored vaccines to mediate systemic and mucosal immune responses through the display or expression of foreign antigens. We will probably observe increasingly more baculovirus-derived products and market licensing of safe and efficacious vaccines. © 2011 Expert Reviews Ltd.
Masson L.,NRC Biotechnology Research Institute
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology | Year: 2010
This perspective discusses current DNA technologies used in basic and applied microbiology research and speculates on possible new future technologies. DNA remains one of the most fascinating molecules known to humans and will continue to revolutionize many areas ranging from medicine, food and forensics to robotics and new industrial bioproducts/biofuel from waste materials. What's next with DNA is not always obvious, but history shows the international microbiology research community will readily adopt it. © 2010 Springer Science+Business Media B.V.
Henry O.,Ecole Polytechnique de Montréal |
Durocher Y.,NRC Biotechnology Research Institute
Metabolic Engineering | Year: 2011
There is an imperative need for expression systems allowing the efficient and robust manufacturing of high quality glycoproteins. In the present work, HEK-293 cells stably expressing interferon-α2b were further engineered with the insertion of the yeast pyruvate carboxylase 2 gene. In batch cultures, marked reductions in lactate and ammonia production were observed compared to the parental cell clone. Although the maximum specific growth rate remained unchanged, the altered metabolism led to a 2-fold increase in maximum cell density and 33% increase in the integral of viable cell concentration and interferon production yield. The underlying metabolic changes were further investigated using various 13C-labeled substrates and measuring the resulting lactate mass isotopomer distributions. Simultaneous metabolite and isotopomer balancing allowed the accurate determination of key intracellular fluxes. Such detailed and quantitative knowledge about the central carbon metabolism of the cells is instrumental to further support the development of high-yield fed-batch processes. © 2011 Elsevier Inc.
Frigon J.-C.,NRC Biotechnology Research Institute |
Guiot S.R.,NRC Biotechnology Research Institute
Biofuels, Bioproducts and Biorefining | Year: 2010
The methane produced from the anaerobic digestion of organic wastes and energy crops represents an elegant and economical means of generating renewable biofuel. Anaerobic digestion is a mature technology and is already used for the conversion of the organic fraction of municipal solid wastes and excess primary and secondary sludge from waste-water treatment plants. High methane yield up to 0.45 m3 STP CH4/kg volatile solids (VS) or 12 390 m3 STP CH4/ ha can be achieved with sugar and starch crops, although these cultures are competing with food and feed crops for high-quality land. The cultivation of lignocellulosic crops on marginal and set-aside lands is a more environmentally sound and sustainable option for renewable energy production. The methane yield obtained from these crops is lower, 0.17-0.39 m3 STP CH4/kg VS or 5400 m3 STP CH4/ha, as its conversion into methane is facing the same initial barrier as for the production of ethanol, for example, hydrolysis of the crops. Intensive research and development on effi cient pre-treatments is ongoing to optimize the net energy production, which is potentially greater than for liquid biofuels, since the whole substrate excepted lignin is convertible into methane. © 2010 Crown in the right of Canada.
Agrawal V.,NRC Biotechnology Research Institute
Methods in molecular biology (Clifton, N.J.) | Year: 2012
Camelid single domain antibodies fused to noncamelid Fc regions, also called chimeric heavy chain antibodies (cHCAb), offer great potential as therapeutic and diagnostic candidates due to their relatively small size (80 kDa) and intact Fc. In this chapter, we describe two approaches, limiting dilution and minipools, for generating nonamplified Chinese hamster ovary cell lines stably expressing cHCAb in suspension and serum-free cultures using a stringent antibiotic selection. Neither of the protocols necessitates the acquisition or implementation of expensive automated infrastructures and thus could be applied in any lab with minimal cell culture setup. The given protocol allows the isolation of stable clones capable of generating up to 100 mg/L of antibody in batch mode performed in shaker flasks.
Dormond E.,NRC Biotechnology Research Institute
Methods in molecular biology (Clifton, N.J.) | Year: 2011
Adenoviral vector (AdV) of the third generation also known as helper-dependent adenoviral vector (HDV) is an attractive delivery system for gene therapy applications. However, obtaining high quality-grade HDV in sufficient amount remains a challenge that hampers the extensive use of this vector in preclinical and clinical studies. Here we review recent progress in the large-scale manufacturing of HDV. The production of HDV is now amenable to large-scale volume with reduced process duration under optimized rescue and co-infection conditions. Also, efficient downstream processing of HDV with acceptable recovery of HDV and minimal contamination by the helper virus is described.
Li J.,NRC Biotechnology Research Institute
Nature communications | Year: 2010
Cancer patients are often overtreated because of a failure to identify low-risk cancer patients. Thus far, no algorithm has been able to successfully generate cancer prognostic gene signatures with high accuracy and robustness in order to identify these patients. In this paper, we developed an algorithm that identifies prognostic markers using tumour gene microarrays focusing on metastasis-driving gene expression signals. Application of the algorithm to breast cancer samples identified prognostic gene signature sets for both estrogen receptor (ER) negative (-) and positive (+) subtypes. A combinatorial use of the signatures allowed the stratification of patients into low-, intermediate- and high-risk groups in both the training set and in eight independent testing sets containing 1,375 samples. The predictive accuracy for the low-risk group reached 87-100%. Integrative network analysis identified modules in which each module contained the genes of a signature and their direct interacting partners that are cancer driver-mutating genes. These modules are recurrent in many breast tumours and contribute to metastasis.
Whiteway M.,NRC Biotechnology Research Institute
Current Biology | Year: 2011
Mating of Ascomycete fungi involves chemically distinct pheromones; one partner makes a lipid-modified peptide, the other partner a simple peptide. A new study has now found that this inherent asymmetry may not be necessary. © 2011 Elsevier Ltd. All rights reserved.
Beauchet R.,Université de Sherbrooke |
Monteil-Rivera F.,NRC Biotechnology Research Institute |
Lavoie J.M.,Université de Sherbrooke
Bioresource Technology | Year: 2012
Conversion of lignin into chemicals and biofuels was performed using the commercial Kraft lignin, Indulin AT. Lignin was depolymerised in an aqueous alkaline solution using a continuous flow reactor generating four fractions. First is the gas fraction (mainly CO2), the second includes methanol, acetic acid and formic acid, thus defined as small organic compounds and third one (up to 19.1wt.% of lignin) is mostly composed of aromatic monomers. The fourth fraction (45-70wt.%) contains oligomers (polyaromatic molecules) and modified lignin. Pyrocatechol was the most abundant product at high severities (315°C) with selectivity up to 25.8%. 31P NMR showed the loss of almost all aliphatic OH groups and apparition of catechol groups during depolymerisation. © 2012 Elsevier Ltd.