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【目的】从苹果根际土壤筛选苹果根系自毒物质降解细菌,并探究分离菌株对根皮苷、邻苯二甲酸、对羟基苯甲酸以及焦性没食子酸的降解能力。【方法】分别采用邻苯二甲酸、焦性没食子酸为唯一碳源富集并筛选其降解菌株。通过对分离菌株的生理生化特征测定及16S r RNA基因序列分析,采用MEGA 5构建系统发育树,进行菌株鉴定。采用紫外分光光度法和高效液相色谱法测定分离菌株对4种自毒物质的降解能力。【结果】共分离5株有降解能力的细菌,编号为BL1、BL2、BL3、BJ1和BJ2,经鉴定BL1为钩虫贪铜菌Cupriavidus necator,BL2为生脂固氮螺菌Azospirillum lipoferum,BL3为氧化烃微杆菌Microbacterium hydrocarbonoxydans,BJ1为Paenibacillus phyllosphaerae,BJ2为Ochrobactrum cytisi。BL1、BL2、BL3菌株对邻苯二甲酸、对羟基苯甲酸、根皮苷、焦性没食子酸的降解率均高于50%。其中BL2菌株的降解效果最好,分别达到66%、72%、84%和84%。【结论】首次发现钩虫贪铜菌、生脂固氮螺菌和氧化烃微杆菌对4种自毒物质均具有很好的降解能力,对缓解自毒物质引起的连作障碍具有潜在的应用价值。
【Objective】 The objective of this study was to screen the apple root from apple rhizosphere soil to detoxify bacteria and study the degradation ability of the isolated strains on phlorizin, phthalic acid, p-hydroxybenzoic acid and pyrogallic acid. 【Method】 Phthalic acid and pyrogallic acid were used as the only carbon sources for enrichment and screening of their degrading strains. The physiological and biochemical characteristics of the isolated strains and 16S rRNA gene sequence analysis, the use of MEGA 5 phylogenetic tree construction, strain identification. The biodegradability of the isolated strains to four kinds of self-toxic substances was determined by UV spectrophotometry and high performance liquid chromatography. 【Result】 Five strains of bacteria with degradability were isolated and identified as BL1, BL2, BL3, BJ1 and BJ2. BL1 was identified as Cupriavidus necator, BL2 was Azospirillum lipoferum, BL3 was oxidized hydrocarbon Microbacterium hydrocarbonoxydans, BJ1 is Paenibacillus phyllosphaerae, and BJ2 is Ochrobactrum cytisi. The degradation rates of phthalic acid, p-hydroxybenzoic acid, phlorizin and pyrogallic acid in BL1, BL2 and BL3 strains were higher than 50%. Among them, BL2 strain had the best degradation efficiency of 66%, 72%, 84% and 84% respectively. 【Conclusion】 The results showed that for the first time, A. coccacia, Azotobacter sphaericus, and Microbacterium oxyhalide were found to have good ability to degrade four kinds of self-toxic substances, and have potential value in alleviating continuous cropping obstacles caused by self-toxic substances.