Kristjansdottir Thordis, Hreggvidsson Gudmundur O, Gudmundsdottir Elisabet Eik, Bjornsdottir Snaedis H, Fridjonsson Olafur H, Stefansson Sigmar Karl, Nordberg Karlsson Eva, Vanhalst Justine, Reynisson Birkir, Gudmundsson Steinn
Matis, Vinlandsleid 12, 113 Reykjavik, Iceland.
Department of Biology, School of Engineering and Natural Sciences, University of Iceland, Sturlugata 7, 102 Reykjavík, Iceland.
FEMS Microbiol Ecol. 2025 Jan 7;101(1). doi: 10.1093/femsec/fiae167.
The thermophilic bacterium Rhodothermus marinus has mainly been studied for its thermostable enzymes. More recently, the potential of using the species as a cell factory and in biorefinery platforms has been explored, due to the elevated growth temperature, native production of compounds such as carotenoids and exopolysaccharides, the ability to grow on a wide range of carbon sources including polysaccharides, and available genetic tools. A comprehensive understanding of the metabolism of cell factories is important. Here, we report a genome-scale metabolic model of R. marinus DSM 4252T. Moreover, the genome of the genetically amenable R. marinus ISCaR-493 was sequenced and the analysis of the core genome indicated that the model could be used for both strains. Bioreactor growth data were obtained, used for constraining the model and the predicted and experimental growth rates were compared. The model correctly predicted the growth rates of both strains. During the reconstruction process, different aspects of the R. marinus metabolism were reviewed and subsequently, both cell densities and carotenoid production were investigated for strain ISCaR-493 under different growth conditions. Additionally, the dxs gene, which was not found in the R. marinus genomes, from Thermus thermophilus was cloned on a shuttle vector into strain ISCaR-493 resulting in a higher yield of carotenoids.
嗜热细菌海栖热袍菌主要因其耐热酶而受到研究。最近，由于其生长温度较高、能天然产生类胡萝卜素和胞外多糖等化合物、能够利用包括多糖在内的多种碳源生长以及有可用的遗传工具，人们探索了将该物种用作细胞工厂和生物精炼平台的潜力。全面了解细胞工厂的代谢很重要。在此，我们报告了海栖热袍菌DSM 4252T的全基因组规模代谢模型。此外，对遗传上易于操作的海栖热袍菌ISCaR - 493的基因组进行了测序，核心基因组分析表明该模型可用于这两个菌株。获得了生物反应器中的生长数据，用于约束模型，并比较了预测的和实验的生长速率。该模型正确预测了两个菌株的生长速率。在重建过程中，对海栖热袍菌代谢的不同方面进行了审视，随后，研究了ISCaR - 493菌株在不同生长条件下的细胞密度和类胡萝卜素产量。此外，将嗜热栖热菌中未在海栖热袍菌基因组中发现的dxs基因克隆到穿梭载体上，导入ISCaR - 493菌株，从而提高了类胡萝卜素的产量。
