Amyris BioProducts Portugal, Unipessoal, Lda. Rua Diogo Botelho 1327, 4169-005, Porto, Portugal.
Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005, Porto, Portugal.
Appl Microbiol Biotechnol. 2023 Jun;107(11):3405-3417. doi: 10.1007/s00253-023-12514-3. Epub 2023 Apr 22.
Yeast cells face various stress factors during industrial fermentations, since they are exposed to harsh environmental conditions, which may impair biomolecules productivity and yield. In this work, the use of an antioxidant peptide extract obtained from industrial spent yeast was explored as supplement for Saccharomyces cerevisiae fermentation to prevent a common bottleneck: oxidative stress. For that, a recombinant yeast strain, producer of β-farnesene, was firstly incubated with 0.5 and 0.7 g/L peptide extract, in the presence and absence of hydrogen peroxide (an oxidative stress inducer), for 1-5 h, and then assayed for intracellular reactive oxygen species, and growth ability in agar spot assays. Results showed that under 2 mM HO the peptide extract could improve cells growth and reduce reactive oxygen species production. Therefore, this antioxidant effect was further evaluated in shake-flasks and 2-L bioreactor batch fermentations. Peptide extract (0.7 g/L) was able to increase yeast resistance to the oxidative stress promoted by 2 mM HO, by reducing reactive oxygen species levels between 1.2- and 1.7-fold in bioreactor and between 1.2- and 3-fold in shake-flask fermentations. Moreover, improvements on yeast cell density of up to 1.5-fold and 2-fold, and on biomolecule concentration of up to 1.6-fold and 2.8-fold, in bioreactor and shake-flasks, respectively, were obtained. Thus, culture medium supplementation with antioxidant peptide extracted from industrial spent yeast is a promising strategy to improve fermentation performance while valuing biomass waste. This valorization can promote a sustainable and eco-friendly solution for the biotechnology industry by the implementation of a circular economy model. KEY POINTS: • Peptide extract from spent yeast applied for the first time on yeast fermentation. • Antioxidant peptide extract enhanced S. cerevisiae oxidative stress resistance. • Fermentation performance under stress improved by peptide extract supplementation.
酵母细胞在工业发酵过程中会面临各种应激因素，因为它们暴露在恶劣的环境条件下，这可能会损害生物分子的生产力和产量。在这项工作中，探索了使用从工业废酵母中获得的抗氧化肽提取物作为酿酒酵母发酵的补充物，以防止常见的瓶颈：氧化应激。为此，首先将β-法呢烯的重组酵母菌株在 0.5 和 0.7 g/L 肽提取物存在或不存在过氧化氢（一种氧化应激诱导剂）的情况下孵育 1-5 小时，然后测定细胞内活性氧和琼脂斑点测定中的生长能力。结果表明，在 2 mM HO 下，肽提取物可以改善细胞生长并减少活性氧的产生。因此，在摇瓶和 2-L 生物反应器分批发酵中进一步评估了这种抗氧化作用。肽提取物（0.7 g/L）能够通过在生物反应器中降低活性氧水平 1.2-1.7 倍和在摇瓶发酵中降低活性氧水平 1.2-3 倍来提高酵母对由 2 mM HO 引起的氧化应激的抗性。此外，在生物反应器和摇瓶中，分别获得了高达 1.5 倍和 2 倍的酵母细胞密度提高，以及高达 1.6 倍和 2.8 倍的生物分子浓度提高。因此，向培养基中补充从工业废酵母中提取的抗氧化肽是一种很有前途的策略，可以在提高发酵性能的同时利用生物质废物。这种利用可以通过实施循环经济模式，为生物技术产业提供可持续和环保的解决方案。 关键点： • 首次将废酵母中的肽提取物应用于酵母发酵。 • 抗氧化肽提取物增强了酿酒酵母的氧化应激抗性。 • 通过添加肽提取物改善了应激下的发酵性能。
