Key Laboratory of Systems Bioengineering, Ministry of Education and Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People's Republic of China.
Appl Environ Microbiol. 2011 Oct;77(19):7023-30. doi: 10.1128/AEM.05123-11. Epub 2011 Jul 29.
The metabolic cooperation in the ecosystem of Bacillus megaterium and Ketogulonicigenium vulgare was investigated by cultivating them spatially on a soft agar plate. We found that B. megaterium swarmed in a direction along the trace of K. vulgare on the agar plate. Metabolomics based on gas chromatography coupled with time-of-flight mass spectrometry (GC-TOF-MS) was employed to analyze the interaction mechanism between the two microorganisms. We found that the microorganisms interact by exchanging a number of metabolites. Both intracellular metabolism and cell-cell communication via metabolic cooperation were essential in determining the population dynamics of the ecosystem. The contents of amino acids and other nutritional compounds in K. vulgare were rather low in comparison to those in B. megaterium, but the levels of these compounds in the medium surrounding K. vulgare were fairly high, even higher than in fresh medium. Erythrose, erythritol, guanine, and inositol accumulated around B. megaterium were consumed by K. vulgare upon its migration. The oxidization products of K. vulgare, including 2-keto-gulonic acids (2KGA), were sharply increased. Upon coculturing of B. megaterium and K. vulgare, 2,6-dipicolinic acid (the biomarker of sporulation of B. megaterium), was remarkably increased compared with those in the monocultures. Therefore, the interactions between B. megaterium and K. vulgare were a synergistic combination of mutualism and antagonism. This paper is the first to systematically identify a symbiotic interaction mechanism via metabolites in the ecosystem established by two isolated colonies of B. megaterium and K. vulgare.
采用软琼脂平板空间培养的方法研究了巨大芽孢杆菌和酮古龙酸发酵短杆菌之间的代谢协同作用。我们发现巨大芽孢杆菌在琼脂平板上沿着酮古龙酸的轨迹向一个方向 swarm。基于气相色谱与飞行时间质谱联用的代谢组学（GC-TOF-MS）被用于分析两种微生物之间的相互作用机制。我们发现，微生物通过交换多种代谢物相互作用。细胞内代谢和通过代谢合作的细胞间通讯对于确定生态系统的种群动态都是必不可少的。与巨大芽孢杆菌相比，酮古龙酸细胞内的氨基酸和其他营养化合物含量相当低，但在酮古龙酸周围的培养基中的这些化合物的水平相当高，甚至高于新鲜培养基。在巨大芽孢杆菌周围积累的赤藓糖、赤藓糖醇、鸟嘌呤和肌醇被迁移的酮古龙酸消耗。酮古龙酸的氧化产物，包括 2-酮基古龙酸（2KGA），在共培养时急剧增加。在巨大芽孢杆菌和酮古龙酸共培养时，与单培养相比，2,6-二吡啶酸（巨大芽孢杆菌孢子形成的生物标志物）显著增加。因此，巨大芽孢杆菌和酮古龙酸之间的相互作用是互利共生和拮抗作用的协同组合。本文首次系统地鉴定了由两个分离的巨大芽孢杆菌和酮古龙酸菌落建立的生态系统中通过代谢物的共生相互作用机制。
