Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada.
Bioengineered. 2023 Dec;14(1):2250950. doi: 10.1080/21655979.2023.2250950.
Bioethanol is a renewable fuel widely used in road transportation and is generally regarded as a clean energy source. Although fermentation is one of the major processes in bioethanol production, studies on improving its efficiency through operational design are limited, especially compared to other steps (pretreatment and hydrolysis/saccharification). In this study, two adapted feeding strategies, in which feed medium addition (sugar delivery) was adjusted to increase the supply of fermentable sugar, were developed to improve ethanol productivity in 5-L fed-batch fermentation by . Specifically, a linear adapted feeding strategy was established based on changes in cell biomass, and an exponential adapted feeding strategy was developed based on cell biomass accumulation. By implementing these two feeding strategies, the overall ethanol productivity reached 0.880.04 and 0.870.06 g/L/h, respectively. This corresponded to 20% increases in ethanol productivity compared to fixed pulsed feeding operations. Additionally, there was no residual glucose at the end of fermentation, and final ethanol content reached 953 g/L under the linear adapted operation and 1043 g/L under the exponential adapted feeding strategy. No statistical difference was observed in the overall ethanol yield (ethanol-to-sugar ratio) between fixed and adapted feeding strategies (91%). These results demonstrate that sugar delivery controlled by adapted feeding strategies was more efficient than fixed feeding operations, leading to higher ethanol productivity. Overall, this study provides novel adapted feeding strategies to improve sugar delivery and ethanol productivity. Integration into the current practices of the ethanol industry could improve productivity and reduce production costs of fermentation processes.
生物乙醇是一种广泛应用于道路交通的可再生燃料，通常被认为是清洁能源。尽管发酵是生物乙醇生产的主要工艺之一，但通过操作设计来提高其效率的研究相对较少，尤其是与其他步骤（预处理和水解/糖化）相比。在这项研究中，开发了两种适应型进料策略，通过调整进料介质（糖的输送）添加量来增加可发酵糖的供应，以提高 5-L 分批补料发酵中的乙醇生产率。具体来说，基于细胞生物量的变化建立了线性适应型进料策略，并且基于细胞生物量积累开发了指数型适应型进料策略。通过实施这两种进料策略，总乙醇生产率分别达到 0.880.04 和 0.870.06 g/L/h，与固定脉冲进料操作相比，乙醇生产率分别提高了约 20%。此外，在发酵结束时没有残留葡萄糖，在线性适应型操作下最终乙醇含量达到 953 g/L，在指数适应型进料策略下达到 1043 g/L。固定和适应型进料策略之间的总乙醇产率（乙醇与糖的比值）没有观察到统计学差异（~91%）。这些结果表明，适应型进料策略控制的糖输送比固定进料操作更有效，从而提高了乙醇生产率。总体而言，本研究提供了新型的适应型进料策略，以改善糖输送和乙醇生产率。将其整合到乙醇工业的当前实践中，可以提高发酵过程的生产率并降低生产成本。
