Biomass compositional data is essential to beginning any study, especially the carbohydrate contents (both soluble and structural carbohydrates) that is the base to calculate theoretical ethanol and sugars yields, to close carbohydrate mass balances, to determine the enzyme loadings, and to calculate the process efficiencies.
- Waxes and fats are extracted into either ether or hexane using sonication.
- The soluble sugars are subsequently extracted in 80% (v/v) ethanol, a concentration which is selective for monosaccharides
- Wateris then used to extract any water-soluble polysaccharides (e.g., fructans)
- Starch is then removed by using amylase in acetate buffer
The final residual material is essentially pure plant cell walls, which is called "structural carbohydrates", including hemicellulose and cellulose. The structural carbohydrates composition will be analysized following two-step acid hydrolysis using H2SO4.
As a complete compositional analysis is labor-intensive, it is often more practical to measure selected components only. Soluble sugars can be extracted by sonication in water if the samples are not to be processed for determining starch contents. For total carbohydrate analysis (including soluble sugars), a two-stage acid hydrolysis procedure similar to NREL protocol can be directly applied to native samples
As a complete compositional analysis is labor-intensive, it is often more practical to measure selected components only. Soluble sugars can be extracted by sonication in water if the samples are not to be processed for determining starch contents. For total carbohydrate analysis (including soluble sugars), a two-stage acid hydrolysis procedure similar to NREL protocol can be directly applied to native samples
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