Saddler J N, Mes-Hartree M
Biotechnology and Chemistry Department, Forintek Canada Corp., Ottawa, Ontario, Canada.
Biotechnol Adv. 1984;2(2):161-81. doi: 10.1016/0734-9750(84)90003-x.
Aspenwood chips were pretreated by steam explosion. The various wood fractions obtained were assayed for their ability to act as substrates for growth and cellulase production of different Trichoderma and Clostridium thermocellum species. Steam exploded aspenwood was as efficiently utilized as solka floc and correspondingly high cellulase activities were detected in the various culture filtrates. When T. harzianum E58 was grown on increasing concentrations of solka floc, highest cellulase and xylanase activities were detected at 1% substrate concentrations while high substrate concentrations (10-20%) inhibited growth and enzyme production. When the cellulosic substrates were supplemented with increasing amounts of glucose, cellulase and xylanase production were inhibited when the glucose concentration exceeded 0.1%. Highest xylanase activities were detected after growth of T. reesei C30 and T. harianum E58 on xylan and solka floc respectively. All of the steam exploded fractions were at least partially hydrolyzed by the T. harzianum E58 cellulase system. The extent of the pretreatment also influenced the ability of Zymomonas mobilis and Saccharomyces cerevisiae to ferment the liberated sugars to ethanol. About 85% of the theoretical yield of ethanol from cellulose could be obtained from the combined hydrolysis and fermentation of pretreated aspenwood.
白杨木片经蒸汽爆破预处理。对获得的各种木材组分进行分析，以评估它们作为不同木霉属和嗜热栖热放线菌生长及纤维素酶生产底物的能力。蒸汽爆破后的白杨木与索尔卡纤维一样能被高效利用，并且在各种培养滤液中检测到了相应较高的纤维素酶活性。当哈茨木霉E58在浓度不断增加的索尔卡纤维上生长时，在底物浓度为1%时检测到最高的纤维素酶和木聚糖酶活性，而高底物浓度（10 - 20%）会抑制生长和酶的产生。当纤维素底物中添加的葡萄糖量不断增加时，当葡萄糖浓度超过0.1%时，纤维素酶和木聚糖酶的产生会受到抑制。里氏木霉C30和哈茨木霉E58分别在木聚糖和索尔卡纤维上生长后，检测到了最高的木聚糖酶活性。所有蒸汽爆破后的组分至少被哈茨木霉E58纤维素酶系统部分水解。预处理的程度也影响了运动发酵单胞菌和酿酒酵母将释放的糖发酵成乙醇的能力。通过预处理白杨木的联合水解和发酵，可获得纤维素乙醇理论产量的约85%。
