Deputy Director of Fungal Biotechnology, Deputy VP of Deconstruction
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, Gladden 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 advanced biofuel from ionic liquid-pretreated biomass.
To further the development of novel enzyme cocktails for lignocellulosic biofuel applications, Gladden has shifted his focus to developing expression systems for high-titer enzyme production. Along with colleagues at PNNL, Gladden 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. Gladden works 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 colleagues at PNNL, leads the Fungal Biotechnology team to engineer fungi to both be platform enzyme production hosts and robust lignocellulose conversion hosts. Establishes protein production baseline and initiate “omics” analysis
- Engineers fungi to express biomass-derived polysaccharide and lignin depolymerizing enzymes
- Engineers fungi to convert both lignocellulose-derived sugars and lignin-derived aromatics to biofuels and bioproducts
- Leads the Biomass Pretreatment and Process Development Team
- Develops and optimizes novel IL and DES pretreatment technologies
- Develops integrated pretreatment to fuels technologies
- Yaegashi, J; Kirby, J; Masakazu, I; Sun, J; Dutta, T; Mirsiaghi, M; Sundstrom, E; Rodriguez, A; Baidoo, E; Tanjore, D; Pray, T; Sale, K; Singh, S; Keasling, J; Simmons, B; Singer, S; Magnuson, J; Arkin, A; Skerker, J; and J Gladden. 2017. Rhodosporidium toruloides: a new platform organism for conversion of lignocellulose into terpene biofuels and bioproducts. Biotechnology for Biofuels. 10:241.
- Liszka, M; Kang, A; Murthy Konda, N,V,S,N; Tran, K; Gladden, J; Singh, S; Keasling, J; Scown, C; Soon Lee, T; Simmons, B; and K Sale. 2016. Switchable ionic liquids based on di-carboxylic acids for one-pot conversion of biomass to an advanced biofuel. Green Chemistry. 4012-4021. (DOI: 10.1039/C6GC00657D)
- Wu, W; Tran, W; Taatjes, C; Alonso-Gutierrez, J; Soon Lee, T; and J Gladden. 2016. Rapid Discovery and Functional Characterization of Terpene Synthases from Four Endophytic Xylariaceae. PLOS ONE.
- Gladden, J; Park, J; Bergmann, J; Reyes-Ortiz, V; D’haeseleer, P; Quirino, B; Sale, K; Simmons, B; and S Singer. 2014. Discovery and characterization of ionic liquid-tolerant thermophilic cellulases from a switchgrass-adapted microbial community. Biotechnol Biofuels. 7:15.
- Park, J; Steen, E; Burd, H; Evans, S; Redding-Johsnon, A; Batth, T; Benke, P; D’haeseleer, P; Sun, N; Sale, K; Keasling, J; Soon Lee, T; Petzold, C; Mukhopadhyay, A; Singer, S; Simmons, B; and John Gladden. 2012. A Thermophilic Ionic Liquid-Tolerant Cellulase Cocktail for the Production of Cellulosic Biofuels. PLoS ONE.
- Gladden, J; Allgaier, M; Miller, CS; Hazen, TC; VanderGheynst, JS; Hugenholtz, P; Simmons, BA; and SW Singer. 2011. Glycoside hydrolase activities of thermophilic bacterial consortia adapted to switchgrass. Applied and Environmental Microbiology. 77(16):5804-12. (doi: 10.1128/AEM.00032-11)