Deinococcus metallilatus MA1002 was exposed to ultraviolet radiation to generate mutants with enhanced biofilm production. Two strains (nos 5 and 6) were then selected based on their high biofilm formation, as well as their possession of higher concentrations of extracellular matrix components (eDNA, protein and saccharides) than the wild-type (WT). Genomic sequencing revealed the presence of large genome deletions in a secondary chromosome in the mutants. Expression analyses of the WT and mutant strains indicated the upregulation of genes associated with exopolysaccharide synthesis and stress response. The mutant strains showed high mortality in glucose-supplemented (TYG) medium; however, cell death and biofilm formation were not increased in mutant cells grown under acetate- or glyoxylate-added media, suggesting that metabolic toxicity during glucose metabolism induced a high rate of cell death but improved biofilm formation in mutant strains. In damaged cells, eDNAs contributed to the enhanced biofilm formation of D. metallilatus .

中文翻译：

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野生型和实验室进化的生物膜过度产生金属奇异球菌菌株的比较基因组学

金属奇异球菌 MA1002 暴露于紫外线辐射以产生具有增强生物膜产生的突变体。然后根据它们的高生物膜形成以及它们比野生型 (WT) 拥有更高浓度的细胞外基质成分 (eDNA、蛋白质和糖类) 选择两个菌株 (nos 5 和 6)。基因组测序揭示了突变体的次级染色体中存在大的基因组缺失。WT 和突变株的表达分析表明与胞外多糖合成和应激反应相关的基因上调。突变株在补充葡萄糖（TYG）培养基中表现出高死亡率；然而，在添加醋酸盐或乙醛酸盐的培养基下生长的突变细胞中，细胞死亡和生物膜形成没有增加，表明葡萄糖代谢过程中的代谢毒性诱导了高细胞死亡率，但改善了突变菌株的生物膜形成。在受损细胞中，eDNA 有助于增强生物膜的形成 D.metallilatus 。