| Recently years, as the main substitution of the fossil fuels, lignocellulose has been the research focus for its renewability and abundance. Currently, the utilizations of rapeseed were mainly for its oil and the extraction for biodiesel, so a large amount of straws were left in the field, which was a huge waste of resource. Utilization of rapeseed straw depend on the improvement of pretreatment technology and efficiency of enzymes, this study is focused on the cell wall components and polymer features of the rapeseed straw, in correlation with rapeseed straw digestibility. Through analyzing of 19 rapeseed straw, we found several main impact factors of rapeseed straw on biomass digestibility under acid or alkaline pretreatments, which is significant for the future rapeseed genetic improvement and utilization as biomass resources. The main results were as the following:1. 19 straw samples from four Brassica species showed diverse cell wall composition, especially Brassica junjea(Bj) and Brassica carinata(Bc) had more lignin and less pectin than Brassica rapa(Br) or Brassica napus(Bn).2. Rapeseed straws exhibited various biomass enzymatic digestibility under sulfuric acid or lime pretreatment. Besides, after the lime pretreatment, they had a higher digestibility than that of the sulfuric acid pretreatment.3. Correlation analysis showed that coniferyl alcohol(G-lignin) and crystalinity index(Cr I) had a strongly negative effect on biomass saccharification, whereas hemicellulosic monosaccharides(fucose, galactose, arabinose and rhamnose) were positive factors.4. Compared with B.junjea, B.napus not only had a higher saccharification efficiency, but also a higher production of the bioethanol.In summary, we explored the key factors of rapeseed for bioenergy, and our results provided useful parameters for the further study on both rapeseed breeding for higher biomass digestibility and better utilization as biomass resources. |
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