School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK.
Department of Chemical and Biomolecular Engineering, College of Design and Engineering, National University of Singapore, 4 Engineering Drive 117585, Singapore.
Bioresour Technol. 2022 Aug;358:127381. doi: 10.1016/j.biortech.2022.127381. Epub 2022 May 26.
Bread is Europe's most wasted food, and the second most wasted food after potatoes in UK. Bread waste (BW) is a clean source of high-quality fermentable sugars. In this study, the potential of Enterobacter ludwigii to accumulate 2,3-butanediol (BDO) from BW was evaluated. Initially, the optimal inoculum size and yeast extract concentration were determined, followed by extraction of sugars from BW using acid and enzymatic hydrolysis. A glucose yield of 330-530 g/kg BW was obtained, and the sugars released were utilised for BDO production by E. ludwigii. The fed-batch cultivation using pure glucose and glucose rich hydrolysates from acid and enzymatic hydrolysis resulted in BDO titres of 144.5, 135.4, and 138.8 g/L, after 96 h, with yield of 0.47, 0.42 and 0.48 g/g yield, respectively. The innovation of the work is valorisation of BW to BDO with a circular biorefining approach and thus, reducing BW disposal and associated environmental burden.
面包是欧洲浪费最多的食物，在英国仅次于土豆，是浪费第二严重的食物。面包废料 (BW) 是一种清洁的高质量可发酵糖源。在这项研究中，评估了肠杆菌属从 BW 中积累 2,3-丁二醇 (BDO) 的潜力。最初，确定了最佳接种量和酵母提取物浓度，然后使用酸和酶解从 BW 中提取糖。获得了 330-530 g/kg BW 的葡萄糖得率，释放的糖被用于肠杆菌属的 BDO 生产。使用纯葡萄糖和酸解及酶解得到的富含葡萄糖的水解产物进行分批补料培养，96 小时后 BDO 的浓度分别达到 144.5、135.4 和 138.8 g/L，产率分别为 0.47、0.42 和 0.48 g/g。这项工作的创新之处在于采用循环生物精炼方法将 BW 转化为 BDO，从而减少 BW 的处理和相关的环境负担。
