Conversion of ammonia-pretreated switchgrass to biofuel precursors by bacterial-fungal consortia under solid-state and submerged-state cultivation.
OBJECTIVE
The aim of this study was to develop and evaluate bacterial-fungal communities to deconstruct switchgrass to biofuel precursors.


RESULTS
Bacterial-fungal consortia, mesophilic (25°C) and thermophilic (50°C), were enriched from switchgrass bales from which enzyme mixtures were used to deconstruct delignified switchgrass (DSG). The bacterial-fungal consortia were able to produce enzymes including endoglucanase, exoglucanase, β-glucosidase, xylanase, xylosidase and pectinase to convert DSG to soluble carbohydrates. 454 pyrosequencing revealed that Paenibacillus and Streptomyces were the dominant bacteria in the mesophilic and thermophilic consortia respectively. Penicillium and Acremonium were the dominant fungi in the mesophilic consortia, whereas Aspergillus and Penicillium were the dominant fungi present in the thermophilic consortia.


CONCLUSIONS
The results show that the state of cultivation, solid-state or submerged-state, affects the community structure as well as enzyme activities produced by these bacterial-fungal consortia. The enzyme mixture produced by the bacterial-fungal consortia released a higher amount of xylose than glucose during saccharification of DSG.


CONCLUSIONS
The study provides a novel approach to produce enzymes for conversion of lignocellulolytic feedstocks to soluble sugars which can be used to produce biofuel precursors.
Biotechnology Institute, University of Minnesota, Twin Cities, Falcon Heights, MN, USA.
A
A
Jain
Department of Biology, Sacred Heart University, Fairfield, CT, USA.
H S
HS
Pelle
University of South Carolina School of Law, Columbia, SC, USA.
W H
WH
Baughman
Department of Biological Sciences, Clemson University, Clemson, SC, USA.
J M
JM
Henson
D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000201:enzymology*; D056804:Biofuels; D050260:Carbohydrate Metabolism; D005658:Fungi / Q000201:enzymology*; D059013:Microbial Consortia; D008897:Panicum / Q000378:metabolism* / Q000382:microbiology; D014994:Xylose / Q000378:metabolism
D056804:Biofuels; D000641:Ammonia; D014994:Xylose
bacterial-fungal consortia; biofuels; lignocellulose degradation; mesophilic; thermophilic