Central Research and Development Department, E. I. du Pont de Nemours and Company, Inc., Experimental Station, Wilmington, Delaware 19898.
Appl Environ Microbiol. 1986 Oct;52(4):733-6. doi: 10.1128/aem.52.4.733-736.1986.
The degradability of ground hardwood by thermophilic anaerobic bacteria (Clostridium thermocellum with or without Thermoanaerobacter strain B6A) was greatly enhanced by pretreatment of the substrate with supercritical ammonia. Relative to C. thermocellum monocultures, cocultures of C. thermocellum and Thermoanaerobacter strain B6A degraded 1.5-fold more pretreated soft maple but produced 2- to 5-fold more fermentation endproducts because Thermoanaerobacter sp. removed reducing sugars produced by C. thermocellum during the fermentation. Dry weight losses were not totally accounted for in end products, due to formation of partially degraded material (<0.4 mum diameter wood particles) during the fermentation. One pretreated hardwood, Southern red oak, was fermented poorly because it released soluble inhibitors at the 60 degrees C incubation temperature. Considerable (6- to 11-fold) increases in substrate degradability were also noted for supercritical ammonia-pretreated wood materials fermented in an in vitro rumen digestibility assay. Degradation of pretreated softwoods by either thermophilic or mesophilic fermentation was not measurable under the conditions tested.
高温厌氧细菌（单独的嗜热梭菌或与热厌氧菌 B6A 共培养）可通过过热氨预处理极大地提高硬木的可降解性。与嗜热梭菌的单培养物相比，嗜热梭菌和热厌氧菌 B6A 的共培养物可降解 1.5 倍的预处理软枫木，但产生 2 到 5 倍的更多发酵终产物，因为热厌氧菌从嗜热梭菌发酵过程中去除了产生的还原糖。由于发酵过程中形成了部分降解的物质（<0.4μm 直径的木屑），因此干重损失并未完全体现在终产物中。一种预处理的硬木，南方红橡木，由于在 60°C 孵育温度下释放出可溶性抑制剂，发酵效果较差。在体外瘤胃消化试验中，对过热氨预处理的木质材料进行发酵时，也观察到可溶物的含量（6-11 倍）显著增加，从而提高了底物的可降解性。在所测试的条件下，未检测到高温或中温发酵对预处理软木的降解作用。
