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ORIGINAL RESEARCH article

Front. Microbiol.

Sec. Microbiotechnology

This article is part of the Research TopicMicrobial Bioremediation of Oil Contaminated SitesView all articles

Hydrocarbon Degradation and Genomic Insights of Klebsiella pneumoniae from Oil-Contaminated Soils in Guimaras Island, Philippines

Provisionally accepted
  • University of the Philippines Los Banos College of Arts and Sciences, Laguna, Philippines

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

Klebsiella was previously found to be the dominant genus of a hydrocarbon-degrading, diesel-enriched microbial consortium from oil-spill contaminated soils in Guimaras Island, Philippines. However, the species-level identity, individual degradation efficiency, and genomic determinants of metabolic pathways and environmental stress adaptation remain unknown, limiting the understanding of the ecological role and bioremediation potential of Klebsiella species. This study isolated, characterized, and evaluated the hydrocarbon degradation efficiencies of Klebsiella species from the consortium. From 110 putative Klebsiella colonies, eleven isolates showed significantly different degradation capacities of at least >66% on diesel, hexane, hexadecane, and xylene, suggesting diversity at the species and strain level, and substrate preference. Isolate KLMG-HD-125 demonstrated complete oxidative degradation of short-and mid-chain n-alkanes (C11–C25) in diesel, indicating a broad substrate range and strong petroleum degradation potential. Whole genome sequence analysis confirmed the identity of KLMG-HD-125 as Klebsiella pneumoniae with a genome size of 5.55 Mb and GC content of 57.2%. It harbors genes responsible for alkane and xylene degradation, and pathways to respond to oxidative, membrane, and solvent stress, indicating ecological fitness, allowing the isolate to remain metabolically active in potentially toxic petroleum-impacted environments. Specifically, the presence of ladA (LadA-like FMN-dependent monooxygenase), adhP (primary alcohol dehydrogenase), and adh (long-chain aldehyde dehydrogenase) indicates the pathway for terminal oxidation of alkanes. Although 11 virulence-associated genes were identified in KLMG-HD-125, the hypervirulence determinants were absent. Together with its environmental origin, these findings indicate that KLMG-HD-125 is potentially opportunistic rather than an obligate pathogen. Overall, KLMG-HD-125 is equipped with phenotypic and genomic traits essential for hydrocarbon remediation, specifically of n-alkanes, and ecological fitness to persist in petroleum-impacted environments, though its potential pathogenicity requries careful biosafety assessment prior to environmental application.

Keywords: bioremediation, Genomics, Klebsiella pneumoniae, microbial hydrocarbon degradation, oil spill

Received: 07 Jan 2026; Accepted: 16 Feb 2026.

Copyright: © 2026 Garcia, Alemania and Opulencia. 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: Rina B. Opulencia

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