Department of Chemical Engineering, Lund University, P.O. Box 124, 22100 Lund, Sweden.
J Biosci Bioeng. 2011 Feb;111(2):167-74. doi: 10.1016/j.jbiosc.2010.10.009. Epub 2010 Nov 16.
Pretreatment, enzymatic hydrolysis and simultaneous saccharification and fermentation (SSF) of the South American straw material Paja Brava were investigated. Suitable process conditions for an SO₂-catalyzed steam pretreatment of the material were determined and assessed by enzymatic digestibility of obtained fiber slurries for 72 h at a water insoluble solids (WIS) content of 2%. The best pretreatment conditions obtained (200 °C, 5 min holding time and 2.5% SO₂) gave an overall glucose yield following enzymatic hydrolysis of more than 90%, and a xylose yield of about 70%. Simultaneous saccharification and co-fermentation of glucose and xylose (SSCF) of the pretreated material using the xylose-fermenting strain Saccharomyces cerevisiae TMB3400 was examined at WIS contents between 5% and 10%. In agreement with previous studies on other materials, the overall ethanol yield and also the xylose conversion decreased somewhat with increasing WIS content in the SSCF. In batch SSCF, the xylose conversion obtained was almost 100% at 5% WIS content, but decreased to 69% at 10% WIS. The highest ethanol concentration obtained for a WIS content of 10% was about 40 g/L, corresponding to a yield of 0.41 g/g in a fed-batch SSCF. The Paja Brava material has previously been found difficult to hydrolyze in a dilute-acid process. However, the SSCF results obtained here show that similar sugar yields and fermentation performance can be expected from Paja Brava as from materials such as wheat straw, corn stover or sugarcane bagasse.
对南美秸秆材料 Paja Brava 进行了预处理、酶解和同步糖化发酵（SSF）研究。通过在 2%不溶性固体（WIS）含量下对获得的纤维浆料进行 72 h 的酶解，确定并评估了适合该材料的 SO₂ 催化蒸汽预处理的工艺条件。获得的最佳预处理条件（200°C，5 分钟保持时间和 2.5% SO₂）在酶解后可获得超过 90%的总葡萄糖产率和约 70%的木糖产率。使用木糖发酵菌株 Saccharomyces cerevisiae TMB3400，在 5%至 10%的 WIS 含量下，对预处理后的材料进行葡萄糖和木糖的同步糖化和共发酵（SSCF）进行了考察。与其他材料的先前研究一致，随着 SSCF 中 WIS 含量的增加，总体乙醇产率和木糖转化率也略有下降。在分批 SSCF 中，在 5%WIS 含量下获得的木糖转化率几乎为 100%，但在 10%WIS 时降至 69%。在 WIS 含量为 10%的条件下，获得的最高乙醇浓度约为 40 g/L，在补料分批 SSCF 中对应的产率为 0.41 g/g。先前已经发现 Paja Brava 材料在稀酸工艺中难以水解。然而，这里获得的 SSCF 结果表明，从 Paja Brava 可以获得类似于小麦秸秆、玉米秸秆或甘蔗渣等材料的相似糖产率和发酵性能。
