Yang Yizi, He Xinxin, Zhang Yulin, Zhang Xiao-Hua
Frontiers Science Center for Deep Ocean Multispheres and Earth System, and College of Marine Life Sciences, Ocean University of China, Qingdao, China.
Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, China.
Front Microbiol. 2025 Apr 28;16:1579612. doi: 10.3389/fmicb.2025.1579612. eCollection 2025.
The Challenger Deep of the Mariana Trench, which is the deepest site in the ocean, contains rich deposits of -alkanes in its sediments. However, the alkane metabolic processes of the bacteria in this extreme environment were not well understood. In this study, we isolated a strain HXX308 () from sediment samples of the Challenger Deep (10,816 meters below sea level). HXX308 grows under pressures ranging from 0 to 40 MPa, with optimal growth at lower pressures. Additionally, it degrades approximately 20% of eicosane at both atmospheric pressure (0.1 MPa) and 20 MPa. Metabolic profiling indicated that HXX308 possesses a complete aerobic alkane metabolism pathway, along with nitrate reduction and sulfate reduction pathways, which support its adaptation to the trench's anoxic environment. Comparative genomic studies showed that most strains in the genus contain the alkane-degrading gene . Characterization of the gene in HXX308 confirmed its role in the degradation of medium-to long-chain alkanes (C). HXX308 is the first strain isolated from marine environment. Although this strain originated from the trench, its hydrocarbon metabolic characteristics are similar to those of cultures of terrestrial origin, suggesting that the alkanes in these sediments are likely from the terrestrial environment. Our study enhances the understanding of alkane-degrading in the phylum and provides insights into the environmental adaptation of HXX308 in the Mariana Trench.
马里亚纳海沟的挑战者深渊是海洋中最深的地方，其沉积物中含有丰富的正构烷烃。然而，在这种极端环境中细菌的烷烃代谢过程尚不清楚。在本研究中，我们从挑战者深渊（海平面以下10,816米）的沉积物样本中分离出一株HXX308（ ）。HXX308在0至40MPa的压力下生长，在较低压力下生长最佳。此外，它在大气压（0.1MPa）和20MPa下均可降解约20%的二十烷。代谢谱分析表明，HXX308拥有完整的好氧烷烃代谢途径，以及硝酸盐还原和硫酸盐还原途径，这支持了它对海沟缺氧环境的适应性。比较基因组研究表明，该属中的大多数菌株都含有烷烃降解基因 。对HXX308中 基因的表征证实了其在中长链烷烃（C）降解中的作用。HXX308是从海洋环境中分离出的第一株 菌株。尽管该菌株起源于海沟，但其烃类代谢特征与陆地来源培养物的特征相似，这表明这些沉积物中的烷烃可能来自陆地环境。我们的研究增进了对 门中烷烃降解的理解，并为HXX308在马里亚纳海沟中的环境适应性提供了见解。
