球黑孢菌Gbh45菌株抗姜青枯菌活性物质分离鉴定及抗菌机制

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中图分类号： 5482+7 文献标识码：A 文章编号：1000-4440（2025）11-2134-12

Abstract：Theaimof this studyis to identifytheactivecomponents inthe fermentationbroth of Nigrospora sphaerica Gbh45 strainthatare efectiveagainst Ralstonia solanacearum，and toelucidate theirantibacterialmechanism.Accordingly， weisolatedandidentifiedtheantimicrobialactivecomponentsinthefermentationbrothofNigrosporasphaericaGbh45strain using silica gelcolumnchromatography，semi-preparative high-performance liquid chromatography（HPLC），andnuclear magneticresonance（NMR）spectroscopy.Weevaluatedtheantibacterial efectsof theactive secondary metabolites from Nigrospora sphaerica Gbh45strainby measuring the growth curvesof Ralstonia solanacearum，along with the minimum inhibitory concentration（ MIC ）andhalf-maximal inhibitory concentration（ IC50 ）.Moreover，we furtherinvestigated theantibacterial mechanism by assessing cell membrane integrity，cell wall damage，and intracellular reactive oxygenspecies（ROS）levels.The results indicated that the antimicrobial secondary metabolite from Nigrospora sphaerica Gbh45 was identified as an anthraquinone compound，9α -hydroxydihydrodesoxybostrycin（ 9α -HDDB）.Itexhibitedaminimuminhibitoryconcentrationof 25.000μg/mL and a half-maximal inhibitory concentration of 8.974μg/mL against Ralstonia solanacearum. 9α -HDDBinhibitsthe growthof Ralstoniasolanacearum primarilybydisrupting cellmembrane integrity，leading tocellwalldamageandtherebyinducing the accumulation of intracelular reactive oxygen species （ROS）. The results showed that 9α -HDDB also exhibited strong inhibitoryeffectsagainstthefoodborne pathogensEscherichiacoliO157：H7and Staphylococcs aureus，indicating itssignificantpotentialfordevelopmentasbothabiocontrolagentagainstRalstoniasolanacearumandafoodantimicrobialagent.

Key words：Nigrospora sphaerica；ginger；Ralstonia solanacearum；active secondary metabolites；antibacterial mechanism

生姜（ZingiberofficinaleRoscoe）是中国广泛种植的一种药食同源植物，富含姜辣素、姜烯酚、姜酮等多种生理活性物质，除用作调味品外，还可预防和治疗消化不良、肠绞痛和失眠等疾病，具有重要的经济价值和药用价值[1-3]。（剩余24066字）