Recombinant Manganese Peroxidase

Lignin is the second most abundant polymer on earth and manganese peroxidase (MnP) is the primary enzyme by which lignin is recycled in the environment. MnP has potential in the biochemical processing of lignocellulosic materials, but only small amounts and concentrations of MnP can be produced with current biotechnologies. Our work involves improving the production of recombinant MnP (rMnP) though genetic engineering techniques and develop systems to use rMnP to modify solid lignin, working toward green, enzymatic conversion of lignin to macromolecules, aromatics and other monomers.

The US and many other countries around the world are investing significant resources in reducing dependence on petroleum for fuels and chemicals to mitigate climate change and energy insecurity. One of the approaches is to convert lignocellulosic biomass, such as straw, corn stover, and even wood, into petroleum replacements.

There are two main platform processing technologies to convert biomass into ethanol, or other fuels and chemicals: the biochemical and the thermochemical platforms. In the biochemical platform, the carbohydrates in lignocellulosic biomass cellulose and hemicelluloses are easily fermented once isolated; however, transforming lignin to a higher value product is a technological hurdle. To achieve significant replacement of petroleum, biofuels must compete in the metrics of properties, cost and scale. Increasingly it is clear that biofuels have achieved parity in properties (e.g. ethanol as a transportation fuel), and are approaching parity in cost (Banerjee et al., 2009), and scale is the next great hurdle before significant replacement can be realized. Developing enzymatic methods to convert lignin to fuels and chemicals directly impacts the scale hurdle as lignin can be as much as 30% of the weight and 40% of the energy content of the raw biomass, and the potentially large volumes of biomass consist of wood and forest waste, with higher lignin content than some agricultural wastes.

Lignin is fundamentally different than the cellulose and hemicellulose fractions of biomass: it is an irregular polymer based on aromatic units, its structure is complex, and the structure varies with biomass source and method of separation.

Microorganisms degrade plant biomass in a series of biochemical reactions that yield materials and energy for cell growth. The first step of this process is the enzyme-catalyzed removal, degradation or separation of the recalcitrant stereo-irregular lignin polymer from the plant matrix. MnP appears to be the most effective lignin-degrading enzyme commonly produced and secreted by microorganisms. Lignin removal renders the cellulose and hemicelluloses susceptible to degradation by cellulases and xylanases, respectively. Cellulose is the most desirable component of plant biomass from the standpoint of both microbial growth and industrial chemical synthesis. Cellulose is the essential component of paper and the most abundant global source of sugars for ethanol fermentations. Effective use of plant biomass for either growth of microorganisms or for use as a manufacturing feedstock requires removal of the lignin.

Our papers in this area include the following:

In progress:

Goby J., Penner M., Lajoie C., and Kelly C. Recombinant manganese peroxidase degradation of methylene blue.

Yee K, Jiang F, Stewart R, Backlund C, Lajoie C, Kelly C. Effect of temperature and air flow rate on the production of recombinant manganese peroxidase.

Yee K., Jansen L., Varin S., Lajoie C. and Kelly C. 2011. Furfural and 5-Hydroxymethyl-Furfural Detoxification using Recombinant Manganese Peroxidase.

Published:

Jiang, Fei; Kongsaeree, Puapong; Schilke, Karl; Lajoie, Curtis; Kelly, Christine. 2008. Effects of pH and Temperature on Recombinant Manganese Peroxidase Production and Stability. Applied Biochemistry and Biotechnology. 146(1-3):15-27.

Jiang, Fei; Kongsaeree, Puapong, Charron, Rose; Lajoie, Curtis; Xu, Haowen; Scott, Gary; Kelly, Christine. 2008. Production and Separation of Manganese Peroxidase from Heme Amended Yeast Cultures. Biotechnology and Bioengineering 99(3):540-549.

Gu, Lina; Lajoie, Curtis A.; Kelly, Christine J. 2003. Expression of a Phanerochaete chrysosporium manganese peroxidase gene in the yeast Pichia pastoris. Biotechnology Progress. 19(5):1403-1409.

Relevant Research Articles
Bioreactor Protocols and Experiments