Department of Materials, Complex Materials, ETH Zürich, Zürich 8093, Switzerland.
Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Zürich 8093, Switzerland.
Proc Natl Acad Sci U S A. 2024 Jul 30;121(31):e2403585121. doi: 10.1073/pnas.2403585121. Epub 2024 Jul 23.
Nature is home to a variety of microorganisms that create materials under environmentally friendly conditions. While this offers an attractive approach for sustainable manufacturing, the production of materials by native microorganisms is usually slow and synthetic biology tools to engineer faster microorganisms are only available when prior knowledge of genotype-phenotype links is available. Here, we utilize a high-throughput directed evolution platform to enhance the fitness of whole microorganisms under selection pressure and identify genetic pathways to enhance the material production capabilities of native species. Using as a model cellulose-producing microorganism, we show that our droplet-based microfluidic platform enables the directed evolution of these bacteria toward a small number of cellulose overproducers from an initial pool of 40,000 random mutants. Sequencing of the evolved strains reveals an unexpected link between the cellulose-forming ability of the bacteria and a gene encoding a protease complex responsible for protein turnover in the cell. The ability to enhance the fitness of microorganisms toward a specific phenotype and to unravel genotype-phenotype links makes this high-throughput directed evolution platform a promising tool for the development of new strains for the sustainable manufacturing of materials.
自然界中存在着各种微生物，它们在环保的条件下创造材料。虽然这为可持续制造提供了一种有吸引力的方法，但天然微生物生产材料的速度通常较慢，而且只有在具有基因型-表型联系的先验知识时，才能利用合成生物学工具来设计生产速度更快的微生物。在这里，我们利用高通量定向进化平台，在选择压力下增强整个微生物的适应性，并确定增强天然物种材料生产能力的遗传途径。我们以 作为纤维素产生微生物的模型，表明我们的基于液滴的微流控平台能够从最初的 40000 个随机突变体中，将这些细菌定向进化为少数几个纤维素高产菌。对进化菌株的测序揭示了细菌纤维素形成能力与编码负责细胞内蛋白质周转的蛋白酶复合物的基因之间的意外联系。这种高通量定向进化平台能够增强微生物对特定表型的适应性，并揭示基因型-表型联系，使其成为开发用于可持续制造材料的新菌株的有前途的工具。
