Departamento de Ingeniería Química, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, México.
Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos 62210, México.
J Ind Microbiol Biotechnol. 2022 Apr 14;49(2). doi: 10.1093/jimb/kuab077.
Teak wood residues were subjected to thermochemical pretreatment, enzymatic saccharification, and detoxification to obtain syrups with a high concentration of fermentable sugars for ethanol production with the ethanologenic Escherichia coli strain MS04. Teak is a hardwood, and thus a robust deconstructive pretreatment was applied followed by enzymatic saccharification. The resulting syrup contained 60 g l-1 glucose, 18 g l-1 xylose, 6 g l-1 acetate, less than 0.1 g l-1 of total furans, and 12 g l-1 of soluble phenolic compounds (SPCs). This concentration of SPC is toxic to E. coli, and thus two detoxification strategies were assayed: (1) treatment with Coriolopsis gallica laccase followed by addition of activated carbon and (2) overliming with Ca(OH)2. These reduced the phenolic compounds by 40% and 76%, respectively. The detoxified syrups were centrifuged and fermented with E. coli MS04. Cultivation with the overlimed hydrolysate showed a 60% higher volumetric productivity (0.45 gETOH l-1 hr-1). The bioethanol/sugar yield was over 90% in both strategies.
柚木残余物经过热化学预处理、酶解和解毒处理，获得了高浓度可发酵糖的糖浆，用于乙醇生产，使用产乙醇的大肠杆菌菌株 MS04。柚木是一种硬木，因此采用了一种强有力的解构预处理方法，然后进行酶解。得到的糖浆含有 60 g/L 葡萄糖、18 g/L 木糖、6 g/L 乙酸、低于 0.1 g/L 的总呋喃和 12 g/L 的可溶酚类化合物（SPC）。这种 SPC 浓度对大肠杆菌有毒，因此测试了两种解毒策略：（1）用栗多孔菌漆酶处理，然后添加活性炭和（2）用 Ca(OH)2 过碱化。这两种方法分别将酚类化合物降低了 40%和 76%。解毒后的糖浆经离心后用大肠杆菌 MS04 发酵。用过碱化水解物培养显示出 60%更高的体积生产率（0.45 gETOH/L/hr）。两种策略的生物乙醇/糖产率都超过 90%。
