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ORIGINAL RESEARCH article

Front. Microbiol.

Sec. Microbial Physiology and Metabolism

Volume 16 - 2025 | doi: 10.3389/fmicb.2025.1579612

Alkane degradation mechanism of Mixta calida HXX308 isolated from sediment of the Mariana Trench

Provisionally accepted
Yizi Yang Yizi Yang 1Xinxin He Xinxin He 1Yulin Zhang Yulin Zhang 1Xiao-Hua Zhang Xiao-Hua Zhang 1,2,3*
  • 1 College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong Province, China
  • 2 Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, China
  • 3 Key Laboratory of Evolution & Marine Biodiversity (Ministry of Education), and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China

The final, formatted version of the article will be published soon.

    The Challenger Deep of the Mariana Trench, which is the deepest site in the ocean, contains rich deposits of n-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 Mixta calida HXX308 (Proteobacteria) 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 Mixta contain the alkane-degrading gene LadB. Characterization of the LadB gene in HXX308 confirmed its role in the degradation of medium-to long-chain alkanes (C18-36). HXX308 is the first Mixta 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 alkanedegrading in the phylum Proteobacteria and provides insights into the environmental adaptation of M. calida HXX308 in the Mariana Trench.

    Keywords: The Mariana Trench, Mixta calida, Proteobacteria, alkane degradation, Comparative genomic analysis

    Received: 19 Feb 2025; Accepted: 01 Apr 2025.

    Copyright: © 2025 Yang, He, Zhang and Zhang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Xiao-Hua Zhang, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, Shandong Province, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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