Zhang Li, Huang Li, Huang Mi, Wang Mengying, Zhu Dekang, Wang Mingshu, Jia Renyong, Chen Shun, Zhao Xinxin, Yang Qiao, Wu Ying, Zhang Shaqiu, Huang Juan, Ou Xumin, Mao Sai, Gao Qun, Tian Bin, Cheng Anchun, Liu Mafeng
Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, China.
Front Microbiol. 2021 Aug 10;12:644868. doi: 10.3389/fmicb.2021.644868. eCollection 2021.
is a gram-negative bacterium that is the first naturally competent bacterium identified in the family . However, the determinants that influence the natural transformation and the underlying mechanism remain unknown. In this study, we evaluated the effects of various nutritional factors of the GCB medium [glucose, L-glutamine, vitamin B1, Fe (NO), NaCl, phosphate, and peptone], on the natural transformation of ATCC 11845. Among the assayed nutrients, peptone and phosphate affected the natural transformation of ATCC 11845, and the transformation frequency was significantly decreased when phosphate or peptone was removed from the GCB medium. When the iron chelator 2,2'-dipyridyl (Dip) was added, the transformation frequency was decreased by approximately 100-fold and restored gradually when Fe (NO) was added, suggesting that the natural transformation of ATCC 11845 requires iron. Given the importance of TonB in nutrient transportation, we further identified whether TonB is involved in the natural transformation of ATCC 11845. Mutation of or , but not , was shown to inhibit the natural transformation of ATCC 11845 in the GCB medium. In parallel, it was shown that the mutant, but not the mutant, decreased iron acquisition in the GCB medium. This result suggested that the mutant affects the natural transformation frequency due to the deficiency of iron utilization.
是一种革兰氏阴性菌，是该家族中首个被鉴定出的天然感受态细菌。然而，影响自然转化的决定因素及其潜在机制仍不清楚。在本研究中，我们评估了GCB培养基的各种营养因子[葡萄糖、L-谷氨酰胺、维生素B1、硝酸铁、氯化钠、磷酸盐和蛋白胨]对嗜水气单胞菌ATCC 11845自然转化的影响。在所检测的营养物质中，蛋白胨和磷酸盐影响嗜水气单胞菌ATCC 11845的自然转化，当从GCB培养基中去除磷酸盐或蛋白胨时，转化频率显著降低。当添加铁螯合剂2,2'-联吡啶（Dip）时，转化频率降低了约100倍，添加硝酸铁后逐渐恢复，这表明嗜水气单胞菌ATCC 11845的自然转化需要铁。鉴于TonB在营养物质运输中的重要性，我们进一步确定TonB是否参与嗜水气单胞菌ATCC 11845的自然转化。嗜水气单胞菌tonB或exbB突变，但不是exbD突变，被证明会抑制GCB培养基中嗜水气单胞菌ATCC 11845的自然转化。同时，结果表明tonB突变体，但不是exbB突变体，会降低GCB培养基中铁的摄取。该结果表明tonB突变体由于铁利用不足而影响自然转化频率。
