John Gladden has 15 years of experience in molecular and cell biology and has worked at JBEI since 2008 developing technologies for the efficient deconstruction of biomass into fermentable sugars for conversion into biofuel. Using advanced ‘omic techniques, John isolated a variety of biomass-degrading bacterial enzymes and, in collaboration with the Microbial Community and Enzyme Engineering teams, used them to develop a cellulase cocktail (called JTherm) that can function in the presence of ionic liquids. It was further demonstrated that this technology could be used to produce advance biofuel from ionic liquid-pretreated biomass.
To further the development of novel enzyme cocktails for lignocellulosic biofuel applications, John has shifted his focus to developing expression systems for high-titer enzyme production. Along with Jon Magnuson and Scott Baker of PNNL, John has established a Fungal Biotechnology group to engineer Aspergillus niger and other fungal strains into expression hosts for heterologous enzymes. These efforts include using forward and reverse genetics to modify the host to promote enzyme expression and the use of ‘omics to develop genetic tools for bioengineering and expression construct design.
In collaboration with the Pretreatment Group at JBEI, JTherm was used in a “one-pot” pretreatment and saccharification bioprocessing configuration to efficiently liberate sugars directly from an IL-pretreatment slurry, greatly simplifying the process and reducing waste water generation. John’s close interactions with the Pretreatment team led him to accept a position as the Interim Director of the Biomass Pretreatment and Process Development Team while the Director Seema Singh was on assignment in DC. John will work to further develop and optimize pretreatment technologies to increase efficiency and reduce cost. He will also use his expertise in biology to develop biocompatible pretreatment technologies that can be integrated with downstream depolymerization and conversion processes.
- With Jon Magnuson, lead the Fungal Biotechnology team to engineer fungi to both be platform enzyme production hosts and robust lignocellulose conversion hosts. Establish protein production baseline and initiate “omics” analysis
- Engineer fungi to express biomass-derived polysaccharide and lignin depolymerizing enzymes
- Engineer fungi to convert both lignocellulose-derived sugars and lignin-derived aromatics to biofuels and bioproducts
- Lead the Biomass Pretreatment and Process Development Team
- Develop and optimize novel IL and DES pretreatment technologies
- Develop integrated pretreatment to fuels technologies
- “Rhodosporidium toruloides: a new platform organism for conversion of lignocellulose into terpene biofuels and bioproducts”, Biotechnology for Biofuels (2017)
- “Switchable Ionic Liquids Based on Di-Carboxylic Acids for One-Pot Conversion of Biomass to an Advanced Biofuel”, Green Chemistry (2016)
- “Rapid Discovery and Functional Characterization of Terpene Synthases from Four Endophytic Xylariaceae”, PLOS ONE (2016)
- “Discovery and characterization of ionic liquid-tolerant thermophilic cellulases from a switchgrass-adapted microbial community”, Biotechnol Biofuels (2014)
- “A thermophilic ionic liquid-tolerant cellulase cocktail for the production of cellulosic biofuels”, PLoS ONE (2012)
- “Glycoside Hydrolase Activities of Thermophilic Bacterial Consortia Adapted to Switchgrass”, Applied and Environmental Microbiology (2011)