从成熟香茅草的鞘部,分离筛选出一株具有明显清新愉悦香味的内生细菌CcSh-1.通过形态学、生理生化和16S rRNA序列分析,鉴定该菌株为菠萝泛菌(Pantoea ananatis).采用顶空气相色谱质谱联用仪技术,检测出CcSh-1的挥发性组分包含以柠檬醛为主要成分的萜类化合物,与香茅草的产香成分相似.综合考察CcSh-1在液体培养条件下的产香效果和生长状况,初步确定CcSh-1的最适宜培养条件:以牛肉膏为碳源,蛋白胨为氮源,温度30 ℃,pH 7.0.同时,培养基中加入1%(w/v)香茅草粉末,能够促进CcSh-1产香,体现了内生菌与其宿主间存在相互作用.%An endophytic bacteria strain CcSh-1 that produced obvious fragrance was successfully isolated from the sheath of Cymbopogon citrates (DC.)Stapf.CcSh-1 strain was identified as Pantoea ananatis by the morphological observation,physiological and biochemical characterization and 16S rRNA sequence analysis.Headspace gas chromatography-mass spectrometry detection showed that the volatile organic components of CcSh-1 were terpenoid and mainly contained citral,which were similar to those of C.citrates and their essential oil.The factors involved in the flavor productivity and the growth status of CcSh-1 were also investigated,and the optimal liquid culture conditions for CsSh-1 were confirmed by taking beef extract as carbon source,and the peptone as nitrogen source,under the temperature of 30℃ and pH 7.0.In addition,it was discovered that the addition of 1% (w/v) abrasive of host plant as substrate can promote the flavor production of CcSh-1,which indicated the interaction between endophyte and its host.
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