Microbial & Enzymatic Technology - Research Activities

Enzymatic Technology

Microbial physiology, ecology and molecular biology of Methylotrophic Microorganisms

Development/Optimization of Fermentation Processes

Downstream Processing

Enzymatic Technology

Contact: Robert Lortie
Tel.: (514) 496-6158
E-mail: robert.lortie@cnrc-nrc.gc.ca

Interest in enzyme-catalyzed biotransformations has been growing in recent years. The Microbial and Enzymatic Technology group has been concentrating on the use of hydrolases to catalyse various condensation reactions. The group's goal is to better understand the behaviour of enzymes in non-aqueous media by using various controlled reaction media, in terms of water concentration and the nature of organic solvents. This approach and the group's expertise have thus far been applied to: the modification of oils and fats using lipases; the resolution of optical isomers through lipase-catalyzed esterification; and the production of biosurfactants through lipase- or glycosidase-catalyzed condensation of sugars and fatty acids or fatty alcohols, respectively. The modification of oils without the use of hydrogenation allows for the production of margarines of higher quality, with a higher content of unsaturated and polyunsaturated fatty acids, and no trans fatty acids. Optical purity of chemicals used as drugs or pesticides is now considered very important, since the non-active optical isomer is at best an unnecessary molecule or is sometimes responsible for side effects. Biodegradable surfactants, produced from renewable agricultural resources, are a good example of environmentally friendly industrial products.

Microbial Physiology, Ecology and Molecular Biology of Methylotrophic Microorganisms

Contact: Carlos Miguez
Tel.: (514) 496-6280
E-mail: carlos.miguez@cnrc-nrc.gc.ca

The Microbial and Enzymatic Technology group has a research team devoted to studying methylotrophic microorganisms. The team is investigating the bacterium Methylobacterium extorquens ATCC 55366, which offers many advantages as a potential expression system for recombinant protein production and for the production of industrially important bulk chemicals. The team has cloned the reporter gene gfp (for Green Fluorescent Protein) into several expression vectors, which help select promoters for the optimal expression of industrially and environmentally pertinent genes. The team is also developing methods to improve the selection of "superexpressing" clones in Pichia pastoris, a methylotrophic yeast. Methane-oxidizing bacteria play an important role in the global carbon cycle and in the mitigation of methane accumulation in the atmosphere. The team is investigating a soluble form of the MMO enzyme, which offers considerable scientific and industrial interest, since it is capable of catalyzing the oxidation and/or bioconversion of over 200 organic compounds. The group's main research interests in this field include the use of molecular biology techniques to determine the diversity of methanotrophic bacteria (at the phylogenetic and functional level) in various environments. These techniques are supporting the detection and isolation of novel methanotrophic bacteria with unique biotransformation and bioremediation capabilities. In addition, the group is using mutagenesis techniques to enhance the catalytic versatility of sMMO and has contributed also to studies on the effect of large land area flooding for hydroelectric power production on methanotrophic populations.

Development/Optimization of Fermentation Processes (small-scale and pilot-scale)

Contact: Denis Groleau
Tel.: (514) 496-6186
E-mail: denis.groleau@cnrc-nrc.gc.ca

A major component of the group's R&D efforts is related to the development, optimization and scale-up of various microbial fermentation processes, generally from the shake flask up to the pilot scale 1,500 L fermentor. Whenever needed, work on primary recovery of the product is also conducted. Most of the work, particularly the work related to industrial activities, is performed using recombinant microorganisms such as Escherichia coli, Pichia pastoris, and Saccharomyces cerevisiae. Other microorganisms such as lactic acid bacteria and specialty yeasts (for example: Zygosaccharomyces rouxii) are also being investigated. Some of the strains have been isolated or genetically engineered by the group while other strains originate from industrial or academic collaborators/clients. An integrated approach is being used to optimize fermentation processes; the approach combines nutritional studies with process control and genetic engineering. In the last ten years or so, the group has developed a particular expertise on the group of methylotrophic bacteria and yeasts.

Downstream Processing

Contact: Gerald Rowe
Tel.: (514) 496-5276
E-mail: gerald.rowe@cnrc-nrc.gc.ca

The Downstream Processing team recovers and purifies proteins that are produced by microbial or animal expression systems. The team also offers to develop purification procedures for clients and partners. All common filtration and chromatographic techniques can be used, up to a volume of approximately 1000 L, allowing for the recovery of multi-gram quantities from microbial fermentation and cell culture. The team makes a special effort to maintain the expertise up to date by incorporating new techniques, such as expanded bed chromatography, in the portfolio of methods offered to the clients and partners. In addition, all standard techniques for the assessment of product quality and quantity are available. This has been applied to numerous proteins and peptides, produced in various expression systems, either under the native form or modified by fusion with an affinity tag such as polyHis.

Related Information

Institutes:

• NRC Biotechnology Research Institute