1）根际益生大肠杆菌

摘要

（1）Whole-genome sequencing (WGS) of microbial isolates is a valuable tool for mapping the genomes of novel organisms and is helpful for understanding plant-bacteria interactions. 微生物分离株的全基因组测序（WGS）是绘制新生物基因组图谱的有力工具，有助于理解植物-细菌相互作用。

（2）The close relationships between bacteria and plants are essential for maintaining healthy ecosystems, whether the bacteria reside in the plant or in the rhizosphere surrounding its roots.细菌与植物之间的密切关系对于维持健康的生态系统至关重要，无论这些细菌是存在于植物体内，还是存在于其根系周围的根际土壤中。

（3）In this study, isolation, characterization, and WGS were performed to identify promising plant growth-promoting rhizobacteria (PGPR) using the rhizospheric soil sample of jatropha tree roots.本研究以麻风树根际土壤为材料，通过分离、鉴定和全基因组测序，筛选具有潜力的植物根际促生菌（PGPR）。

（4）Out of 100 isolates, six (FACU 2024, 2, 3, 4, 5, and 6) exhibited phosphate-solubilizing bacteria (PSB) traits, including solubilizing phosphate and producing indole acetic acid (IAA), and the ability of other plant growth-promoting (PGP) traits was tested.在100个分离株中，有6株（FACU 2024、2、3、4、5和6）表现出解磷菌（PSB）特性，包括溶解磷酸盐和产生吲哚乙酸（IAA），并对它们其他植物促生（PGP）特性的能力进行了测试。

（5）Isolate FACU 2024 exhibited the highest values for IAA production (12.1 µg/ml), soluble phosphate release (300 µg/ml), and phosphate solubilization index (6.7).分离株FACU 2024在IAA产量（12.1 µg/ml）、可溶性磷酸盐释放量（300 µg/ml）和磷酸盐溶解指数（6.7）方面均表现出最高值。

（6）Therefore, FACU 2024 was molecularly identified as Escherichia coli. 因此，FACU 2024被分子鉴定为大肠杆菌（Escherichia coli）。

（7）The WGS analysis revealed that E. coli FACU 2024 possesses one chromosome and one plasmid with a total length of 4.8 Mb and were submitted on GenBank under accession numbers CP147009 and CP147010.全基因组测序分析显示，E. coli FACU 2024含有一条染色体和一个质粒，总长度为4.8 Mb，其序列已提交至GenBank，登录号为CP147009和CP147010。

（8）The bacterial genome contained about 142 PGP genes, ranging from 258 to 3744 bp and associated with phosphate solubilization, siderophore production, indole acetic acid (IAA) production, nitrogen metabolism, nitrogen fixation, and nitrite/nitrate reduction. 该细菌基因组包含约142个PGP相关基因，长度范围为258至3744 bp，这些基因与磷酸盐溶解、铁载体产生、吲哚乙酸（IAA）产生、氮代谢、固氮以及亚硝酸盐/硝酸盐还原等功能相关。

（9）Moreover, genomic islands (GIs) were enriched with genes associated with horizontal gene transfer (HGT), stress response, and environmental adaptation, and prophage analyses were carried out. 此外，基因组岛（GIs）富含与水平基因转移（HGT）、胁迫响应和环境适应相关的基因，并进行了前噬菌体分析。

（10）In addition, 15 heavy metal resistance genes were annotated, such as those for As, Cd, Zn, Pb, Cu, Fe, and Co, ranging from 426 to 2505 bp. 此外，还注释了15个重金属抗性基因，长度范围为426至2505 bp，这些基因针对的金属包括砷（As）、镉（Cd）、锌（Zn）、铅（Pb）、铜（Cu）、铁（Fe）和钴（Co）。

（11）This study provides the first comprehensive genetic evidence linking E. coli to key PGPR traits alongside genes conferring resistance to multiple heavy metals. 本研究首次提供了将大肠杆菌与关键PGPR特性以及赋予多种重金属抗性的基因相关联的全面遗传学证据。

（12）This strain demonstrates potential as a PGPR in addition to heavy metal bioremediation.该菌株展示了作为PGPR的潜力，同时还可用于重金属生物修复。

（13）Result

（14）Physiochemical properties of the rhizospheric soil sample 根际土壤样品的理化性质

（15）Isolation and characterization of PGP isolates PGP分离物的分离和鉴定

（16）Quantitative estimation of soluble P and IAA 可溶性磷和吲哚乙酸的定量估算

（17）Complete genome sequencing of E. coli FACU 2024

（18）Evaluation of HM removal of the promising strain FACU 2024菌株FACU 2024去除重金属的评价

The close relationships between bacteria and plants are essential for maintaining healthy ecosystems, whether the bacteria reside in the plant or in the rhizosphere surrounding its roots.细菌与植物之间的密切关系对于维持健康的生态系统至关重要，无论这些细菌是存在于植物体内，还是存在于其根系周围的根际土壤中。