Allelochemicals are metabolites produced by living organisms that have a detrimental effect on other species when released into the environment. These chemicals play critical roles in the problems associated with crop replanting. Benzoic acid is a representative allelochemical found in root exudates and rhizosphere soil of crops and inhibits crop growth. The bioremediation of allelochemicals by microorganisms is an efficient decontamination process. In this research, a bacterial strain capable of degrading benzoic acid as the sole carbon source was isolated. The genome of the strain was sequenced, and biodegradation characteristics and metabolic mechanisms were examined. Strain SCB32 was identified as Pseudomonas sp. based on 16S rRNA gene analysis coupled with physiological and biochemical analyses. The degradation rate of 800 mg L^-1 benzoic acid by strain SCB32 was greater than 97.0% in 24 h. The complete genome of strain SCB32 was 6.3 Mbp with a GC content of 64.6% and 5960 coding genes. Potential benzoic acid degradation genes were found by comparison to the KEGG database. Some key intermediate metabolites of benzoic acid, such as catechol, were detected by gas chromatography-mass spectrometry. The biodegradation pathway of benzoic acid, the ortho pathway, is proposed for strain SCB32 based on combined data from genome annotation and mass spectrometry. Moreover, the benzoic acid degradation products from strain SCB32 were essentially nontoxic to lettuce seedlings, while seeds in the benzoic acid-treated group showed significant inhibition of germination. This indicates a possible application of strain SCB32 in the bioremediation of benzoic acid contamination in agricultural environments.

中文翻译：

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苯甲酸降解细菌假单胞菌sp。的完整基因组序列和生物降解特性 SCB32。

化感物质是由活生物体产生的代谢产物，当释放到环境中时会对其他物种产生有害影响。这些化学物质在与农作物重新种植有关的问题中起着至关重要的作用。苯甲酸是在作物的根系分泌物和根际土壤中发现的一种典型的化感物质，可抑制作物的生长。微生物对化感物质的生物修复是一种有效的净化过程。在这项研究中，分离出能够降解苯甲酸作为唯一碳源的细菌菌株。对菌株的基因组进行测序，并检查其生物降解特性和代谢机制。菌株SCB32被鉴定为假单胞菌sp。基于16S rRNA基因分析以及生理和生化分析。800 mg L ^-1的降解率SCB32菌株在24小时内的苯甲酸大于97.0％。SCB32菌株的完整基因组为6.3 Mbp，GC含量为64.6％，编码基因为5960。通过与KEGG数据库进行比较，发现了潜在的苯甲酸降解基因。气相色谱-质谱法检测了苯甲酸的一些关键中间代谢产物，例如儿茶酚。基于基因组注释和质谱的综合数据，提出了菌株SCB32的苯甲酸生物降解途径，即邻位途径。此外，菌株SCB32的苯甲酸降解产物对莴苣幼苗基本无毒，而苯甲酸处理组的种子表现出显着的发芽抑制作用。