Bippus Lars, Briem Ann-Kathrin, Beck Alexander, Zibek Susanne, Albrecht Stefan
Department Life Cycle Engineering GaBi, Institute for Acoustics and Building Physics IABP, University of Stuttgart, Stuttgart, Germany.
Department Life Cycle Engineering GaBi, Fraunhofer Institute for Building Physics IBP, Stuttgart, Germany.
Front Bioeng Biotechnol. 2024 Feb 23;12:1347452. doi: 10.3389/fbioe.2024.1347452. eCollection 2024.
This study assesses the environmental impacts of mannosylerythritol lipids (MELs) production for process optimization using life cycle assessment (LCA). MELs are glycolipid-type microbial biosurfactants with many possible applications based on their surface-active properties. They are generally produced by fungi from the family of Ustilaginaceae via fermentation in aerated bioreactors. The aim of our work is to accompany the development of biotechnological products at an early stage to enable environmentally sustainable process optimization. This is done by identifying hotspots and potentials for improvement based on a reliable quantification of the environmental impacts. The production processes of MELs are evaluated in a cradle-to-gate approach using the Environmental Footprint (EF) 3.1 impact assessment method. The LCA model is based on upscaled experimental data for the fermentation and purification, assuming the production at a 10 m³ scale. In the case analyzed, MELs are produced from rapeseed oil and glucose, and purified by separation, solvent extraction, and chromatography. The results of the LCA show that the provision of substrates is a major source of environmental impacts and accounts for 20% of the impacts on Climate Change and more than 70% in the categories Acidification and Eutrophication. Moreover, 33% of the impacts on Climate Change is caused by the energy requirements for aeration of the bioreactor, while purification accounts for 42% of the impacts respectively. For the purification, solvents are identified as the main contributors in most impact categories. The results illustrate the potentials for process optimization to reduce the environmental impacts of substrate requirements, enhanced bioreactor aeration, and efficient solvent use in downstream processing. By a scenario analysis, considering both experimental adaptations and prospective variations of the process, the laboratory development can be supported with further findings and hence efficiently optimized towards environmental sustainability. Moreover, the presentation of kinetic LCA results over the fermentation duration shows a novel way of calculating and visualizing results that corresponds to the way of thinking of process engineers using established environmental indicators and a detailed system analysis. Altogether, this LCA study supports and demonstrates the potential for further improvements towards more environmentally friendly produced surfactants.
本研究使用生命周期评估（LCA）来评估甘露糖赤藓糖醇脂（MELs）生产对环境的影响，以实现工艺优化。MELs是糖脂类微生物生物表面活性剂，基于其表面活性特性有许多可能的应用。它们通常由黑粉菌科的真菌通过在曝气生物反应器中发酵产生。我们工作的目的是在生物技术产品开发的早期阶段提供支持，以实现环境可持续的工艺优化。这是通过基于对环境影响的可靠量化来识别热点和改进潜力来实现的。使用环境足迹（EF）3.1影响评估方法，以从摇篮到大门的方式评估MELs的生产过程。LCA模型基于发酵和纯化的放大实验数据，假设生产规模为10立方米。在所分析的案例中，MELs由菜籽油和葡萄糖生产，并通过分离、溶剂萃取和色谱法进行纯化。LCA结果表明，底物的供应是环境影响的主要来源，占气候变化影响的20%，在酸化和富营养化类别中占比超过70%。此外，气候变化影响的33%是由生物反应器曝气的能源需求造成的，而纯化分别占影响的42%。对于纯化，溶剂被确定为大多数影响类别中的主要贡献者。结果说明了工艺优化在减少底物需求、增强生物反应器曝气和下游加工中有效使用溶剂对环境影响方面的潜力。通过情景分析，考虑实验调整和工艺的前瞻性变化，可以用进一步的研究结果支持实验室开发，从而有效地朝着环境可持续性进行优化。此外，在发酵持续时间内呈现动态LCA结果展示了一种计算和可视化结果的新方法，这与使用既定环境指标和详细系统分析的过程工程师的思维方式相对应。总之，这项LCA研究支持并证明了在生产更环保表面活性剂方面进一步改进的潜力。
