Núñez Mauricio, Naciff Antonia, Cuadros Fabián, Rojas Constanza, Carvallo Gastón, Yáñez Carolina
Laboratorio de Microbiología, Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso 234000, Chile.
Laboratorio de Ecología Vegetal, Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso 234000, Chile.
Int J Mol Sci. 2025 Jun 18;26(12):5842. doi: 10.3390/ijms26125842.
Extremophilic bacteria from extreme environments, such as the Atacama Desert, Salar de Huasco, and Antarctica, exhibit adaptations to intense UV radiation. In this study, we investigated the genomic and structural mechanisms underlying UV resistance in three bacterial isolates identified as PQ169, sp. AMH3-8, and T1-13. Through integrative genomic analyses, we identified key genes involved in DNA-repair systems, pigment production, and spore formation. Phylogenetic analyses of aminoacidic sequences of the nucleotide excision repair (NER) system revealed conserved evolutionary patterns, indicating their essential role across diverse bacterial taxa. Structural modeling of photolyases from sp. AMH3-8 and T1-13 provided further insights into protein function and interactions critical for DNA repair and UV resistance. Additionally, the presence of a complete violacein operon in T1-13 underscores pigment biosynthesis as a crucial protective mechanism. In PQ169, we identified the complete set of genes responsible for sporulation, suggesting that sporulation may represent a key protective strategy employed by this bacterium in response to environmental stress. Our comprehensive approach underscores the complexity and diversity of microbial adaptations to UV stress, offering potential biotechnological applications and advancing our understanding of microbial resilience in extreme conditions.
来自极端环境（如阿塔卡马沙漠、瓦斯科盐沼和南极洲）的嗜极细菌表现出对强烈紫外线辐射的适应性。在本研究中，我们调查了三种被鉴定为PQ169、AMH3-8菌株和T-13的细菌分离株中抗紫外线的基因组和结构机制。通过综合基因组分析，我们确定了参与DNA修复系统、色素产生和孢子形成的关键基因。对核苷酸切除修复（NER）系统氨基酸序列的系统发育分析揭示了保守的进化模式，表明它们在不同细菌类群中起着重要作用。对AMH3-8菌株和T-13的光解酶进行结构建模，进一步深入了解了对DNA修复和抗紫外线至关重要的蛋白质功能和相互作用。此外，T-13中完整的紫菌素操纵子的存在强调了色素生物合成作为一种关键的保护机制。在PQ169中，我们确定了负责孢子形成的完整基因集，这表明孢子形成可能是该细菌应对环境压力所采用的一种关键保护策略。我们的综合方法强调了微生物对紫外线压力适应的复杂性和多样性，提供了潜在的生物技术应用，并增进了我们对极端条件下微生物恢复力的理解。
