Martins Tiago M, Martins Celso, Guedes Paula, Silva Pereira Cristina
Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal.
CENSE-Center for Environmental and Sustainability Research, Department of Environmental Sciences and Engineering, NOVA School of Science and Technology, NOVA University Lisbon, Caparica, Portugal.
mSystems. 2021 Jan 26;6(1):e00230-20. doi: 10.1128/mSystems.00230-20.
In fungi, salicylate catabolism was believed to proceed only through the catechol branch of the 3-oxoadipate pathway, as shown, e.g., in However, the observation of a transient accumulation of gentisate upon the cultivation of in salicylate medium questions this concept. To address this, we have run a comparative analysis of the transcriptome of these two species after growth in salicylate using acetate as a control condition. The results revealed the high complexity of the salicylate metabolism in with the concomitant positive regulation of several pathways for the catabolism of aromatic compounds. This included the unexpected joint action of two pathways-3-hydroxyanthranilate and nicotinate-possibly crucial for the catabolism of aromatics in this fungus. Importantly, the 3-hydroxyanthranilate catabolic pathway in fungi is described here for the first time, whereas new genes participating in the nicotinate metabolism are also proposed. The transcriptome analysis showed also for the two species an intimate relationship between salicylate catabolism and secondary metabolism. This study emphasizes that the central pathways for the catabolism of aromatic hydrocarbons in fungi hold many mysteries yet to be discovered. Aspergilli are versatile cell factories used in industry for the production of organic acids, enzymes, and pharmaceutical drugs. To date, bio-based production of organic acids relies on food substrates. These processes are currently being challenged to switch to renewable nonfood raw materials-a reality that should inspire the use of lignin-derived aromatic monomers. In this context, aspergilli emerge at the forefront of future bio-based approaches due to their industrial relevance and recognized prolific catabolism of aromatic compounds. Notwithstanding considerable advances in the field, there are still important knowledge gaps in the central catabolism of aromatic hydrocarbons in fungi. Here, we disclose a novel central pathway, 3-hydroxyanthranilate, defying previously established ideas on the central metabolism of the aromatic amino acid tryptophan in We also observe that the catabolism of the aromatic salicylate greatly activated the secondary metabolism, furthering the significance of using lignin-derived aromatic hydrocarbons as a distinctive biomass source.
在真菌中，人们认为水杨酸酯分解代谢仅通过3-氧代己二酸途径的儿茶酚分支进行，例如，如[具体文献]所示。然而，在水杨酸酯培养基中培养[具体真菌名称]时观察到龙胆酸的短暂积累，这对这一概念提出了质疑。为了解决这个问题，我们以乙酸盐作为对照条件，对这两个物种在水杨酸酯中生长后的转录组进行了比较分析。结果揭示了[具体真菌名称]中水杨酸酯代谢的高度复杂性，同时伴随着几种芳香化合物分解代谢途径的正调控。这包括两条途径——3-羟基邻氨基苯甲酸和烟酸——的意外联合作用，这可能对这种真菌中芳香化合物的分解代谢至关重要。重要的是，这里首次描述了真菌中的3-羟基邻氨基苯甲酸分解代谢途径，同时还提出了参与烟酸代谢的新基因。转录组分析还表明，这两个物种的水杨酸酯分解代谢与次级代谢之间存在密切关系。这项研究强调，真菌中芳香烃分解代谢的核心途径仍有许多有待发现的奥秘。曲霉菌是工业上用于生产有机酸、酶和药物的多功能细胞工厂。迄今为止，基于生物的有机酸生产依赖于食品底物。目前，这些工艺正面临着转向可再生非食品原料的挑战——这一现实应该会促使人们使用木质素衍生的芳香单体。在这种背景下，由于曲霉菌的工业相关性以及其公认的丰富的芳香化合物分解代谢能力，它们在未来基于生物的方法中处于前沿地位。尽管该领域取得了相当大的进展，但真菌中芳香烃核心分解代谢仍存在重要的知识空白。在这里，我们揭示了一条新的核心途径——3-羟基邻氨基苯甲酸，这与之前关于[具体真菌名称]中芳香族氨基酸色氨酸中心代谢的既定观点相悖。我们还观察到，芳香族水杨酸酯的分解代谢极大地激活了次级代谢，进一步凸显了使用木质素衍生的芳香烃作为独特生物质来源的重要性。
