Lei Lei, Chen Jiahui, Liao Weifang, Liu Pulin
College of Biological and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan, China.
Front Microbiol. 2020 Dec 3;11:573857. doi: 10.3389/fmicb.2020.573857. eCollection 2020.
is one of the most diverse bacterial genera identified in the environment. Genome sequence analysis has indicated that this genus can be clustered into three lineages and ten groups. Each group can adopt different mechanisms to thrive under zinc-depleted or high-zinc conditions, two environments that are frequently encountered during their environmental propagation. The response of three prominent strains ( PAO1, KT2440, and ATCC 13525) to minimal inhibitory concentrations of zinc were compared using RNA-seq and ultra-performance liquid chromatography-tandem mass spectrometry analysis. Results demonstrated that the three strains shared only minimal similarity at the transcriptional level. Only four genes responsible for zinc efflux were commonly upregulated. PAO1 specifically downregulated the operons involved in siderophore synthesis and the genes that encode ribosomal protein, while upregulated the genes associated with antibiotic efflux and cell envelope biosynthesis. The membrane transporters in KT2440 were globally downregulated, indicating changes in cell permeability. Compared with PAO1 and KT2440, the most remarkable transcriptional variation in ATCC 13525 is the significant downregulation of the type VI secretion system. Metabolite quantitative analysis showed that low concentrations of the metabolites involved in central carbon metabolism and amino acid synthesis were detected in the three strains. In summary, the cellular responses of the three strains under high-zinc condition is quite divergent. Although similar metal efflux systems were upregulated, the three strains employed different pathways to reduce zinc intrusion. In addition, zinc treatment can increase the difficulties of scavenging from its colonization area, and reduce the competitiveness of in microbiota.
是在环境中鉴定出的最多样化的细菌属之一。基因组序列分析表明，该属可分为三个谱系和十个组。每组在锌缺乏或高锌条件下可以采用不同的机制来生长，这两种环境是它们在环境传播过程中经常遇到的。使用RNA测序和超高效液相色谱 - 串联质谱分析比较了三种突出菌株（PAO1、KT2440和ATCC 13525）对锌的最低抑菌浓度的反应。结果表明，这三种菌株在转录水平上仅有极小的相似性。只有四个负责锌外排的基因普遍上调。PAO1特异性地下调了参与铁载体合成的操纵子和编码核糖体蛋白的基因，同时上调了与抗生素外排和细胞膜生物合成相关的基因。KT2440中的膜转运蛋白整体下调，表明细胞通透性发生了变化。与PAO1和KT2440相比，ATCC 13525中最显著的转录变化是VI型分泌系统的显著下调。代谢物定量分析表明，在这三种菌株中检测到了参与中心碳代谢和氨基酸合成的低浓度代谢物。总之，这三种菌株在高锌条件下的细胞反应差异很大。虽然相似的金属外排系统被上调，但这三种菌株采用了不同的途径来减少锌的侵入。此外，锌处理会增加从其定殖区域清除的难度，并降低其在微生物群落中的竞争力。
