Hyunjae Woo, Youngshin Kim, Dohyeon Kim & Sung Ho Yoon
Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Republic of Korea.
Corresponding author : Sung Ho Yoon
Abstract
Carbon source-dependent control of bacterial growth is fundamental to bacterial physiology and survival. However, pinpointing the metabolic steps important for cell growth is challenging due to the complexity of cellular networks. Here, the elastic net model and multilayer perception model that integrated genome-wide gene-deletion data and simulated flux distributions were constructed to identify metabolic reactions beneficial or detrimental to Escherichia coli grown on 30 different carbon sources. Both models outperformed traditional in silico methods by identifying not just essential reactions but also nonessential ones that promote growth. They successfully predicted metabolic reactions beneficial to cell growth, with high convergence between the models. The models revealed that biosynthetic pathways generally promote growth across various carbon sources, whereas the impact of energy-generating pathways varies with the carbon source. Intriguing predictions were experimentally validated for findings beyond experimental training data and the impact of various carbon sources on the glyoxylate shunt, pyruvate dehydrogenase reaction, and redundant purine biosynthesis reactions. These highlight the practical significance and predictive power of the models for understanding and engineering microbial metabolism.
산업 분야에서는 미생물을 통하여 효소, 바이오 연료, 의약품과 같은 고부가가치의 대사산물을 생산합니다. 이를 가능하게 하는 핵심기술은 대사공학인데, 이를 위해서는 미생물 시스템의 전체 대사과정을 상세히 규명하는 것이 중요합니다. 그러나 간단한 대장균조차 수천 개의 대사유전자(metabolic genes), 대사반응(metabolic reactions), 대사물질(metabolites)들이 서로 복잡하게 얽혀있어 특정 대사시스템을 직관적으로 이해하기는 쉽지 않습니다.