Degradation potential and pathways of methylcyclohexane by bacteria derived from Antarctic surface water. (July 2023)

• Record Type: Journal Article
• Authors: Li, Yingchao; Cui, Zhisong; Luan, Xiao; Bian, Xinqi; Li, Guoqing; Hao, Tong; Liu, Jinyan; Feng, Ke; Song, Yizhi
• Is Part Of: Chemosphere. Volume 329(2023)
• Publication Date: 2023-07
• Subjects: Cyclic alkanes -- Methylcyclohexane -- Metagenome-assembled genomes -- Lactone formation -- Aromatization; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2023.138647
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Cycloalkanes pose a tremendous environmental risk due to their high concentration in petroleum hydrocarbons and hazardous effects to organisms. Numerous studies have documented the biodegradation of acyclic alkanes and aromatic hydrocarbons. However, insufficient attention has been paid to studies on the microbial degradation of cycloalkanes, which might be closely linked to psychrophilic microbes derived from low-temperature habitats. Here we show that endemic methylcyclohexane (MCH, an abundant cycloalkane species in oil) consumers proliferated in seawater samples derived from the Antarctic surface water (AASW). The MCH-consuming bacterial communities derived from AASW exhibited a distinct species composition compared with their counterparts derived from other cold-water habitats. We also probed Colwellia and Roseovarius as the key active players in cycloalkane degradation by dilution-to-extinction-based incubation with MCH as sole source of carbon and energy. Furthermore, we propose two nearly complete MCH degradation pathways, lactone formation and aromatization, concurrently in the high-quality metagenome-assembled genomes of key MCH consumer Roseovarius . Overall, we revealed that these Antarctic microbes might have strong interactions that enhance the decomposition of more refractory hydrocarbons through complementary degradation pathways. Graphical abstract: Image 1 Highlights: Slow-growing endemic Antarctic bacteria proliferate on cycloalkane. Antarctic cycloalkane consumers exhibit distinct bacterial community structures. Key endemic Antarctic bacteria involved in cycloalkane degradation were determined. Two complementary degradation pathways for MCH were proposed in Antarctic bacteria.