机构地区:[1]昆明学院农学与生命科学学院高原湖泊生态与环境健康云南省高校协同创新中心,昆明650214
出 处:《生物技术通报》2024年第9期225-237,共13页Biotechnology Bulletin
基 金:国家自然科学基金项目(42167009);云南省教育厅科学研究基金项目(2022Y712,2023Y0874);云南省高校联合基金项目(2018FH001-004);云南省教育厅云南高原湖泊-北美五大湖国际联合科技创新团队。
摘 要:【目的】探究解磷菌及其发酵产物在铅污染土壤中对玉米(Zea mays L.)根际土壤性质和微生物群落组成和多样性的影响。【方法】在筛选具有耐铅解磷功能的巴氏克雷伯氏菌(Klebsiella pasteurii)的基础上,采用盆栽实验在铅污染土壤中培育种植玉米,在其根际施加LB培养基、上清液(菌剂分泌物)、菌液(只含菌体细胞)和发酵液(上清液+菌体细胞),并设置无菌水对照,探究解磷菌对根际土壤理化性质及微生物群落结构的影响。【结果】巴氏克雷伯氏菌的上清液、菌液和发酵液对玉米根际细菌群落多样性并无显著影响,而菌液显著增加了土壤真菌群落的Shannon指数和Chao指数;菌株的上清液、菌液、发酵液均增加了拟杆菌门(Bacteroidetes)与放线菌门(Actinobacteria)等耐重金属的微生物类群的相对丰度,同时上清液、发酵液增加了变形菌门(Proteobacteria)和被孢霉门(Mortierellomycota)的丰度,上清液提高了鞘氨醇单胞菌属(Sphingomonas)、芽球菌属(Blastococcus)、慢生根瘤菌属(Bradyrhizobium)、古根菌属(Archaeorhizomyces)的相对丰度。此外,对玉米根际土壤差异菌属进行皮尔逊相关性分析,有7组差异菌属之间为正相关性,揭示了不同微生物菌属之间更趋向于形成互利共生关系。菌株的上清液、菌液、发酵液均显著增加了土壤酸性磷酸酶(Acp)的活性,其中在发酵液处理组中玉米根际土壤Acp活性最高为574.44 mg/g,24-1,施用上清液、菌液显著增加了根际土壤中碱解氮(AN)的含量,较对照组分别增加了47.4%、39.5%,三个处理组均显著降低了土壤pH值。通过冗余分析(RDA)发现土壤AN、Acp、pH值、可溶性磷(AP)是影响微生物群落结构的主要影响因素。【结论】外源施用解磷菌及其发酵产物有利于改善铅污染土壤肥力质量,影响土壤微生物群落的组成和结构,为铅污染农田接种解磷菌并提高土壤养分、改善土壤微生物群�【Objective】To explore the effects of phosphate-solubilizing bacteria(PSB)and their fermentation products on the properties of maize(Zea mays L.)rhizosphere soil and the composition and diversity of microbial community in lead-contaminated soil.【Method】Based on the screening of Klebsiella pasteurii with lead-resistant and phosphate-solubilizing function,corn was cultivated in leadcontaminated soil by pot experiment.LB medium,supernatant(bacterial secretion),bacterial solution(only bacterial cells)and fermentation broth(supernatant+bacterial cells)were applied to the rhizosphere,and sterile water control was set to explore the effects of phosphatesolubilizing bacteria on the physical and chemical properties of rhizosphere soil and microbial community structure.【Result】The supernatant,bacterial liquid and fermentation liquid of K.baumannii had no significant effect on the diversity of bacterial community in maize rhizosphere,while the bacterial liquid significantly increased the Shannon index and Chao index of soil fungal community.The supernatant,bacterial liquid and fermentation liquid of the strain increased the relative abundances of heavy metal-resistant microbial groups such as Bacteroidetes and Actinobacteria,while the supernatant and fermentation liquid increased the abundances of Proteobacteria and Mortierellomycota.The supernatant increased the relative abundances of Sphingomonas,Blastococcus,Bradyrhizobium and Archaeorhizomyces.In addition,Pearson correlation analysis of differential genera in the maize rhizosphere soil showed that there were positive correlations among 7 groups of differential genera,which revealed that different microbial genera tended to form mutually beneficial symbiotic relationships.The supernatant,bacterial liquid and fermentation liquid of the strain significantly increased the activities of soil acid phosphatase(Acp).Among them,the Acp activity of maize rhizosphere soil in the fermentation liquid treatment group was the highest(574.44 mg/g,24-1).The application of sup
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