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Identifying the key organisms, pathways and locations of hydrogen fermentation from lignocellulosic biomass in wood-feeding Passalid beetles.

EMSL Project ID


Passalid beetles, such as Odontotaenius disjunctus, are subsocial insects that process large amounts of woody biomass by feeding on triturated wood. With the development of symbiotic relationships with gut microbes, Passalid beetles have enriched their genetic pool and metabolic capabilities to survive on a low-nutrient diet. The hindgut microbial community provides digestive enzymes that degrade complex polysaccharides and lignins of plant cells. The gut microbiome of these beetles has evolved to efficiently extract energy from lignocellulosic materials. The specific aim of this proposal is to obtain proteomic and metabolomic data to test hypotheses regarding the key organisms and the spatial localization of processes related to plant polymer decomposition and subsequent hydrogen fermentation processes in these beetle guts. Due to their highly stratified gut morphology, these beetles serve as excellent model systems for studying the spatial organization of microbial functions that sequentially contribute to the degradation of plant biomass -- in essence they represent a natural production line or biorefinery. By understanding the way in which these processes are organized in space and time in this beetle's digestive tract we can begin to identify the characteristics traits of this system that result in efficient energy extraction from plant polymers and to reconstruct the flow of carbon and energy through distinct biogeochemical zones.

Project Details

Project type
Large-Scale EMSL Research
Start Date
End Date


Principal Investigator

Eoin Brodie
Lawrence Berkeley National Laboratory

Team Members

Javier Ceja Navarro
Lawrence Berkeley National Laboratory

Jennifer Pett-Ridge
Lawrence Livermore National Laboratory

Kristin Burnum-Johnson
Environmental Molecular Sciences Laboratory

Mary Lipton
Environmental Molecular Sciences Laboratory

Related Publications

Ceja Navarro J., U. Karaoz, M. Bill, Z. Hao, R.A. White, A. Arellano, and L. Ramanculova, et al. 2019. "Gut anatomical properties and microbial functional assembly promote lignocellulose deconstruction and colony subsistence of a wood-feeding beetle." Nature Microbiology 4, no. 5:864-875. PNNL-SA-138060. doi:10.1038/s41564-019-0384-y