Department of Biology, Section for Microbiology, Aarhus University, Aarhus, Denmark; Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, Cluj-Napoca, Romania.
Department of Biology, Section for Microbiology, Aarhus University, Aarhus, Denmark.
Curr Opin Microbiol. 2024 Jun;79:102486. doi: 10.1016/j.mib.2024.102486. Epub 2024 May 10.
This review synthesizes recent discoveries of novel archaea clades capable of oxidizing higher alkanes, from volatile ones like ethane to longer-chain alkanes like hexadecane. These archaea, termed anaerobic multicarbon alkane-oxidizing archaea (ANKA), initiate alkane oxidation using alkyl-coenzyme M reductases, enzymes similar to the methyl-coenzyme M reductases of methanogenic and anaerobic methanotrophic archaea (ANME). The polyphyletic alkane-oxidizing archaea group (ALOX), encompassing ANME and ANKA, harbors increasingly complex alkane degradation pathways, correlated with the alkane chain length. We discuss the evolutionary trajectory of these pathways emphasizing metabolic innovations and the acquisition of metabolic modules via lateral gene transfer. Additionally, we explore the mechanisms by which archaea couple alkane oxidation with the reduction of electron acceptors, including electron transfer to partner sulfate-reducing bacteria (SRB). The phylogenetic and functional constraints that shape ALOX-SRB associations are also discussed. We conclude by highlighting the research needs in this emerging research field and its potential applications in biotechnology.
本综述综合了最近发现的能够氧化更高烷烃的新型古菌类群，从挥发性烷烃如乙烷到更长链烷烃如十六烷。这些古菌被称为厌氧多碳烷烃氧化古菌（ANKA），它们使用烷基辅酶 M 还原酶启动烷烃氧化，这些酶类似于产甲烷菌和厌氧甲烷氧化古菌（ANME）的甲基辅酶 M 还原酶。多系烷烃氧化古菌组（ALOX），包含 ANME 和 ANKA，拥有越来越复杂的烷烃降解途径，与烷烃链长相关。我们讨论了这些途径的进化轨迹，强调了代谢创新和通过横向基因转移获得代谢模块。此外，我们还探讨了古菌将烷烃氧化与电子受体还原偶联的机制，包括将电子转移给硫酸盐还原菌（SRB）等伙伴。还讨论了影响 ALOX-SRB 关联的系统发育和功能限制。最后，我们强调了这一新兴研究领域的研究需求及其在生物技术中的潜在应用。
