Rivard C J, Grohmann K
Applied Biological Sciences Section, Solar Energy Research Institute, Golden, CO 80401.
Appl Biochem Biotechnol. 1991 Spring;28-29:285-95. doi: 10.1007/BF02922608.
Furfural, a byproduct formed during the thermal/chemical pretreatment of hemicellulosic biomass, was degraded to methane and carbon dioxide under anaerobic conditions. The consortium of anaerobic microbes responsible for the degradation was enriched using small continuously stirred tank reactor (CSTR) systems with daily batch feeding of biomass pretreatment liquor and continuous addition of furfural. Although the continuous infusion of furfural was initially inhibitory to the anaerobic CSTR system, adaptation of the consortium occurred rapidly with high rates of furfural addition. Addition rates of 7.35 mg furfural/700-mL reactor/d resulted in biogas productions of 375%, of that produced in control CSTR systems, fed the biomass pretreatment liquor only. The anaerobic CSTR system fed high levels of furfural was stable, with a sludge pH of 7.1 and methane gas composition of 69%, compared to the control CSTR, which had a pH of 7.2 and 77% methane. CSTR systems in which furfural was continuously added resulted in 80% of the theoretically expected biogas. Intermediates in the anaerobic biodegradation of furfural were determined by spike additions in serum-bottle assays using the enriched consortium from the CSTR systems. Furfural was converted to several intermediates, including furfuryl alcohol, furoic acid, and acetic acid, before final conversion to methane and carbon dioxide.
糠醛是半纤维素生物质热/化学预处理过程中形成的一种副产物，在厌氧条件下可降解为甲烷和二氧化碳。利用小型连续搅拌釜式反应器（CSTR）系统，每天分批加入生物质预处理液并持续添加糠醛，富集负责降解的厌氧微生物群落。尽管最初连续注入糠醛对厌氧CSTR系统有抑制作用，但随着糠醛添加量的增加，群落迅速适应。糠醛添加速率为7.35 mg糠醛/700 mL反应器/天，产生的沼气产量是仅加入生物质预处理液的对照CSTR系统的375%。与pH值为7.2且甲烷含量为77%的对照CSTR相比，添加高浓度糠醛的厌氧CSTR系统较为稳定，污泥pH值为7.1，甲烷气体含量为69%。连续添加糠醛的CSTR系统产生的沼气量为理论预期量的80%。通过在血清瓶试验中加入从CSTR系统富集的群落，确定了糠醛厌氧生物降解的中间产物。在最终转化为甲烷和二氧化碳之前，糠醛先转化为几种中间产物，包括糠醇、糠酸和乙酸。
