Design and characterization of synthetic fungal-bacterial consortia for direct production of isobutanol from cellulosic biomass
Design and characterization of synthetic fungal-bacterial consortia for direct production of isobutanol from cellulosic biomass
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DOI：
10.1073/pnas.1218447110
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发表时间：
2013-09-03
影响因子：
11.1
通讯作者：
Lin, Xiaoxia Nina
中科院分区：
文献类型：
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作者：
Minty, Jeremy J.;Singer, Marc E.;Lin, Xiaoxia Nina
协同微生物群落在自然界中无处不在，并表现出吸引人的特征，如复杂的代谢能力和健壮性。这激发了人们对生物技术发展的工程合成微生物联盟的快速增长的兴趣。然而，关于它们在实际应用中的使用的报道相对较少，并且实现种群稳定和监管已被证明具有挑战性。在这项工作中，我们将生态学理论与工程原理结合起来，开发强大的合成真菌-细菌联合体，以有效地从木质纤维素原料中合成有价值的产品。所需的生物功能分为两种：一种是真菌里氏木霉（Trichoderma reesei），它分泌纤维素酶将木质纤维素生物质水解成可溶性糖，另一种是细菌大肠杆菌（Escherichia coli），它将可溶性糖代谢成所需的产物。我们建立并实验验证了T. reesei/E的综合数学模型。大肠杆菌联合体，提供对系统性能的关键决定因素的见解。为了说明这个联合体的生物加工潜力，我们演示了微晶纤维素和预处理玉米秸秆直接转化为异丁醇。在没有昂贵的营养补充的情况下，我们获得了高达1.88 g/L的滴度和高达理论最大值62%的产量。此外，我们还证明了T. reesei/E中的合作-作弊动态。大肠杆菌群体导致稳定的种群平衡，并提供了一种调整组成的机制。虽然我们提供异丁醇生产作为概念验证应用，但我们的模块化系统可以很容易地用于生产许多其他有价值的生物化学品。
Synergistic microbial communities are ubiquitous in nature and exhibit appealing features, such as sophisticated metabolic capabilities and robustness. This has inspired fast-growing interest in engineering synthetic microbial consortia for biotechnology development. However, there are relatively few reports of their use in real-world applications, and achieving population stability and regulation has proven to be challenging. In this work, we bridge ecology theory with engineering principles to develop robust synthetic fungal-bacterial consortia for efficient biosynthesis of valuable products from lignocellulosic feedstocks. The required biological functions are divided between two specialists: the fungus Trichoderma reesei, which secretes cellulase enzymes to hydrolyze lignocellulosic biomass into soluble saccharides, and the bacterium Escherichia coli, which metabolizes soluble saccharides into desired products. We developed and experimentally validated a comprehensive mathematical model for T. reesei/E. coli consortia, providing insights on key determinants of the system's performance. To illustrate the bioprocessing potential of this consortium, we demonstrate direct conversion of microcrystalline cellulose and pretreated corn stover to isobutanol. Without costly nutrient supplementation, we achieved titers up to 1.88 g/L and yields up to 62% of theoretical maximum. In addition, we show that cooperator-cheater dynamics within T. reesei/E. coli consortia lead to stable population equilibria and provide a mechanism for tuning composition. Although we offer isobutanol production as a proof-of-concept application, our modular system could be readily adapted for production of many other valuable biochemicals.