发酵

ABSTRACT(#br)Pervaporation is an alternative to distillation for recovering ethanol produced by fermentation of grains and biomass. Ethanol-selective mixed matrix membranes of the hydrophobic zeolite ZSM-5 in polydimethylsiloxane (PDMS) have superior performance compared to pure PDMS membranes in pervaporation of clean ethanol/water solutions, but are susceptible to performance reduction when pervaporating fermentation broths. The effects of pervaporating a variety of solutions with 60\u003cce:hsp sp=\"0.25\"/\u003ewt% ZSM-5/PDMS membranes were studied.

Abstract(#br)Organophilic pervaporation (OPV) has been considered as one of the most promising separation processes for the recovery of biofuels from fermentation broths, however, in addition to preferred target product – liquid biofuels, the yeast cells and fermentation nutrients could affect the recovery efficiency of biofuels from broths by pervaporation.

摘要\n生物乙醇是一种很有前途的化石燃料替代品，主要通过酵母发酵生产。然而，在传统的分批发酵过程中，胞外乙醇的积累限制了酵母胞内乙醇的排泄，从而抑制了酵母的活力和乙醇产量。本研究报道了在渗透汽化膜反应器中，酵母固定化的催化活性膜用于高效去除胞外乙醇，以提高生物乙醇的产率。通过在聚二甲基硅氧烷( PDMS )渗透汽化膜上涂复多孔酵母/聚醚砜催化层，采用浸没相转化法制备了该膜。由于生物催化层的高孔隙率，固定化酵母在较高底物浓度下比游离酵母具有更好的发酵能力。最重要的是，通过比较催化活性膜反应器( CAMR )、惰性膜反应器和间歇反应器的发酵性能，CAMR的乙醇产率最高( 3.05 g L-1 h-1 )，酵母质量浓度最高( 26.41 g L-1 )，表明CAMR的酵母生长的酵母生长速率和活力。我们认为这是由于生物催化活性膜的“真正”原位清除能力：细胞外乙醇从酵母附近被迅速清除，促进了抑制剂(细胞内乙醇)的快速排出，从而最大限度地消除了细胞内乙醇的不良抑制作用。