Elucidating temporal-spatial patterns in lignocellulose degradation by morphologically distinct anaerobe gut fungi

Anaerobe gut fungi (AGF) are powerful degraders of untreated lignocellulose and therefore hold high potential for exploitation in renewables-based biotechnology. These fungi leverage degradative enzyme complexes in combination with filamentous morphological structures – rhizoids – that penetrate and are thought to disrupt lignocellulose structures. However, significant questions remain about the degradative effect of AGF; the chemical and structural changes brought about in lignocellulose are largely unknown, the actual contribution of filamentous rhizoids to degradation is not established, and regulation of enzyme production is still poorly understood.
Based on the distinctively different effect on the model substrate cellulose of AGF species with filamentous rhizoids and those without (bulbous, yeast-like appearance), we hypothesize that fungi with these two morphotypes will leverage distinct degradative mechanisms.
The overall objective here is to test this hypothesis via assessment of spatial-temporal patterns in lignocellulose degradation of AGF morphological types with and without rhizoids. Specific aims are
1) to provide detailed insight in the spatial-temporal chemical and structural changes in the biofuel feedstock wheat straw, as brought about during its degradation by AGF species of different morphotypes. This will be achieved via assessment of changes in lignocellulose structure via ssNMR and XRD, changes in surface exposed material via ToF-SIMS, and sophisticated compositional analysis.
2) Insight in these compositional changes in lignocellulose will be complemented by assessment of temporal-spatial patterns of fungal activity in these AGF species in response to growth on wheat straw, where the fungi constantly respond to changes in this lignocellulose during its degradation. To achieve this,
a) temporal changes in fungal activity will be assessed via time-course transcriptomics and proteomics of AGF cultures grown on wheat straw.
b) spatial differences in fungal activity will be investigated by combining localisation of enzyme-encoding transcripts via FISH and their target substrates via immunohistochemistry.
Together this data uncovers mechanisms by which AGF bring about chemical and structural changes in lignocellulose, and thus provides direct insight in degradative mechanisms leveraged by morphologically distinct types of AGF. This in turn will contribute to exploitation of these mechanisms in lignocellulose-based biotechnology.