Katzen R, Fowler D E
Raphael Katzen Associates International, Inc., Cincinnati, OH.
Appl Biochem Biotechnol. 1994 Spring;45-46:697-707. doi: 10.1007/BF02941841.
This article presents the advanced technology that has been developed by BioEnergy International of Gainesville, Florida, utilizing novel recombinant strains of bacteria developed by Lonnie Ingram of the University of Florida. The first commercial applications of these unique fermenting organisms convert 5-carbon sugars, as well as 6-carbon sugars, and oligomers of cellulose (e.g., cellobiose and cellotriose) directly to ethanol. The proposed systems that will be utilized for conversion of agricultural wastes, mixed waste papers, and pulp and paper mill waste in forthcoming commercial installations are now under design. This involves the extensive experience of Raphael Katzen Associates International, Inc. in acid hydrolysis, enzyme production, enzymatic hydrolysis, large-scale fermentation engineering, and distillation/dehydration. Specific examples of this advanced technology will be presented in different applications, namely: 1. Conversion of the hemicellulose content of sugar cane bagasse to 5-carbon sugars by mild-acid prehydrolysis, followed by fermentation of the 5-carbon sugar extract with recombinant Escherichia coli in a commercial installation soon to be under construction in Brazil. This unique process utilizes the surplus hemicellulose fraction of bagasse not required for steam and power generation to produce ethanol, additional to that from the original can juice, which has been converted by conventional sucrose fermentation to ethanol. The process also recovers and converts to ethanol the majority of sucrose normally lost with the bagasse fibers. Resultant beer is enriched in an innovative process to eliminate the need for incremental rectification capacity. 2. Application of this technology to mixed waste paper in Florida, with a moderate loading of newsprint (85% mechanical wood fiber), will involve a mild-acid prehydrolysis, the partial extraction of the 5-carbon sugars produced from hemicellulose as a feedstock for propagation of the recombinant Klebsiella oxytoca bacterium. Included is a facility providing for in-house production of cellulase enzyme, as an active whole broth for direct use in simultaneous saccharification and fermentation (SSF) of the remaining cellulose and residual 5-carbon sugars to ethanol. This is followed by distillation and dehydration in the advanced commercially available low-energy recovery system. 3. Another potential application of this unique technology involves utilization of a variety of wastes from several pulp and paper mills in close proximity, permitting collection of these wastes at low cost and reducing the considerable cost encountered in disposing of such low-energy wet waste.(ABSTRACT TRUNCATED AT 400 WORDS)
本文介绍了佛罗里达州盖恩斯维尔市的生物能源国际公司所开发的先进技术，该技术利用了佛罗里达大学朗尼·英格拉姆培育的新型重组细菌菌株。这些独特的发酵生物体的首次商业应用可将戊糖、己糖以及纤维素低聚物（如纤维二糖和纤维三糖）直接转化为乙醇。即将在未来商业装置中用于转化农业废弃物、混合废纸以及纸浆和造纸厂废料的拟议系统目前正在设计中。这需要拉斐尔·卡岑国际公司在酸水解、酶生产、酶水解、大规模发酵工程以及蒸馏/脱水方面的丰富经验。本文将在不同应用中展示这项先进技术的具体实例，即：1. 通过温和酸预水解将甘蔗渣中的半纤维素含量转化为戊糖，随后在巴西即将建设的一座商业装置中，用重组大肠杆菌对戊糖提取物进行发酵。这一独特工艺利用甘蔗渣中多余的半纤维素部分（蒸汽和发电不需要的部分）来生产乙醇，除了从原甘蔗汁中通过传统蔗糖发酵转化得到的乙醇外，该工艺还能回收并将通常随甘蔗渣纤维流失的大部分蔗糖转化为乙醇。通过创新工艺浓缩所得的发酵液，无需增加精馏能力。2. 将这项技术应用于佛罗里达州的混合废纸（新闻纸含量适中，含85%机械木纤维），将涉及温和酸预水解，从半纤维素产生的戊糖作为原料进行部分提取，用于繁殖重组产酸克雷伯菌。其中包括一个内部生产纤维素酶的设施，以活性全发酵液的形式直接用于剩余纤维素和残留戊糖同时糖化发酵（SSF）生产乙醇。随后在先进的市售低能量回收系统中进行蒸馏和脱水。3. 这项独特技术的另一个潜在应用涉及利用附近几家纸浆和造纸厂的各种废料，这样可以低成本收集这些废料，并降低处理此类低能量湿废料所遇到的高昂成本。（摘要截选至400字）
