%0 Journal Article
%T Biological conversion assay using Clostridium phytofermentans to estimate plant feedstock quality
%A Scott J Lee
%A Thomas A Warnick
%A Sivakumar Pattathil
%A Jes¨²s G Alvelo-Maurosa
%A Michelle J Serapiglia
%A Heather McCormick
%A Virginia Brown
%A Naomi F Young
%A Danny J Schnell
%A Lawrence B Smart
%A Michael G Hahn
%A Jeffrey F Pedersen
%A Susan B Leschine
%A Samuel P Hazen
%J Biotechnology for Biofuels
%D 2012
%I BioMed Central
%R 10.1186/1754-6834-5-5
%X We used the anaerobic bacterium Clostridium phytofermentans to develop a robust assay for biomass digestibility and conversion to biofuels. The assay utilizes the ability of the microbe to convert biomass directly into ethanol with little or no pre-treatment. Plant samples were added to an anaerobic minimal medium and inoculated with C. phytofermentans, incubated for 3 days, after which the culture supernatant was analyzed for ethanol concentration. The assay detected significant differences in the supernatant ethanol from wild-type sorghum compared with brown midrib sorghum mutants previously shown to be highly digestible. Compositional analysis of the biomass before and after inoculation suggested that differences in xylan metabolism were partly responsible for the differences in ethanol yields. Additionally, we characterized the natural genetic variation for conversion efficiency in Brachypodium distachyon and shrub willow (Salix spp.).Our results agree with those from previous studies of lignin mutants using enzymatic saccharification-based approaches. However, the use of C. phytofermentans takes into consideration specific organismal interactions, which will be crucial for simultaneous saccharification fermentation or consolidated bioprocessing. The ability to detect such phenotypic variation facilitates the genetic analysis of mechanisms underlying plant feedstock quality.Lignocellulosic plant biomass is comprised mostly of cell walls, which are a complex composite of proteins, lignin, and polysaccharides; the latter holds promise as raw material for biofuel production. The most abundant polysaccharide in the majority of tissues is cellulose, which exists as unbranched chains containing up to 15,000 ¦Â-(1,4)-linked glucose molecules [1]. By contrast, the shorter hemicelluloses are chemically and physically more complex [2]. The most abundant forms exist as glucan chains much shorter than cellulose or ¦Â-(1,4)-linked xylose, both with diverse side-chain substitut
%U http://www.biotechnologyforbiofuels.com/content/5/1/5