Certain bacteria are resistant to antibiotics and can even transform antibiotics in the environment. It is unclear how the molecular mechanisms underlying the resistance and biotransformation processes vary under different environmental conditions. The objective of this study is to investigate the molecular mechanisms of tetracycline resistance and biotransformation by Stenotrophomonas maltophilia strain DT1 under various background nutrient conditions. Strain DT1 was exposed to tetracycline for 7 days with four background nutrient conditions: no background (NB), peptone (P), peptone plus citrate (PC), and peptone plus glucose (PG). The biotransformation rate follows the order of PC > P > PG > NB ≈ 0. Genomic analysis showed that strain DT1 contained tet(X1), a gene encoding an FAD-binding monooxygenase, and eight peroxidase genes that could be relevant to tetracycline biotransformation. Quantitative proteomic analyses revealed that nodulation protein transported tetracycline outside of cells; hypoxanthine–guanine phosphoribosyltransferase facilitated the activation of the ribosomal protection proteins to prevent the binding of tetracycline to the ribosome and superoxide dismutase and peroxiredoxin-modified tetracycline molecules. Comparing different nutrient conditions showed that the biotransformation rates of tetracycline were positively correlated with the expression levels of superoxide dismutase.

中文翻译：

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基因组学和蛋白质组学研究表明，背景营养素影响嗜麦芽窄食单胞菌对四环素的生物转化。

某些细菌对抗生素具有抗性，甚至可以在环境中转化抗生素。目前尚不清楚在不同的环境条件下，抗药性和生物转化过程的分子机制如何变化。这项研究的目的是研究在不同背景营养条件下嗜麦芽窄食单胞菌DT1菌株对四环素抗性和生物转化的分子机制。将DT1菌株暴露于四环素中，具有四种背景营养条件：无背景（NB），蛋白ept（P），蛋白one加柠檬酸盐（PC）和蛋白ept加葡萄糖（PG）。生物转化率遵循PC> P> PG> NB≈0的顺序。基因组分析表明，菌株DT1包含tet（X1），一个编码FAD结合单加氧酶的基因，和八个与四环素生物转化有关的过氧化物酶基因。定量蛋白质组学分析表明，结瘤蛋白将四环素转运到细胞外。次黄嘌呤-鸟嘌呤磷酸核糖基转移酶促进了核糖体保护蛋白的活化，以防止四环素与核糖体，超氧化物歧化酶和过氧化物酶毒素修饰的四环素分子结合。比较不同的营养条件表明，四环素的生物转化率与超氧化物歧化酶的表达水平呈正相关。