Gugel Irene, Marchetti Filippo, Costa Stefania, Baldini Erika, Vertuani Silvia, Manfredini Stefano
Department of Life Sciences and Biotechnology, University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy.
Bioresour Bioprocess. 2025 Mar 19;12(1):20. doi: 10.1186/s40643-025-00847-y.
The utilization of low-cost, waste-derived lignocellulosic biomass for biotechnological lactic acid production is an area of significant interest. Although numerous attempts have been made to develop novel processes using second-generation feedstocks, the downstream recovery processes for second-generation lactic acid are still relatively uncharted. In this context, this study explores a two-step method for retrieving second-generation lactic acid from a fermented olive leaves medium. The initial step involves an aqueous two-phase extraction using an ethanol/ammonium sulfate system, a method first applied here to lactic acid derived from second-generation raw materials. This is followed by a purification step using activated carbon. The process succeeded in extracting second-generation lactic acid with a yield of 70.02 ± 2.29% in the first extraction stage, followed by a yield of 88.91 ± 0.49% in the second purification step. The lactic acid purity level at the end of the downstream process was 90.17 ± 1.55%, as confirmed by the HPLC data. Furthermore, the study examined the feasibility of direct lactic acid extraction from unfiltered, fermented olive leaves medium, revealing that up to 95.23 ± 0.42% of bacterial cells could be eliminated. The purified lactic acid underwent qualitative identification through FT-IR and H-NMR analysis, with the spectra showing a high degree of similarity to a standard reference substance, thus demonstrating the use of low-cost waste lignocellulosic biomass for the biotechnological production of lactic acid is a topic of great interest.
利用低成本、源自废弃物的木质纤维素生物质进行生物技术法生产乳酸是一个备受关注的领域。尽管已经进行了许多尝试来开发使用第二代原料的新工艺，但第二代乳酸的下游回收工艺仍相对未知。在此背景下，本研究探索了一种从发酵橄榄叶培养基中回收第二代乳酸的两步法。第一步涉及使用乙醇/硫酸铵体系进行双水相萃取，该方法首次应用于从第二代原料衍生的乳酸。接下来是使用活性炭的纯化步骤。该工艺在第一个萃取阶段成功提取了第二代乳酸，产率为70.02±2.29%，随后在第二个纯化步骤中的产率为88.91±0.49%。根据HPLC数据，下游工艺结束时乳酸的纯度水平为90.17±1.55%。此外，该研究考察了从未过滤的发酵橄榄叶培养基中直接萃取乳酸的可行性，结果表明高达95.23±0.42%的细菌细胞可以被去除。通过FT-IR和H-NMR分析对纯化的乳酸进行了定性鉴定，光谱显示与标准参考物质高度相似，因此表明利用低成本废弃木质纤维素生物质进行生物技术生产乳酸是一个非常有趣的课题。
