玉米共生细菌生物膜形成与其根表定殖相关性分析

Correlation Analysis of Biofilm Formation and its Root Surface Colonization in Maize Symbiotic Bacteria

摘要:

为研究玉米共生细菌生物膜形成能力与根表定殖能力的相关性，采用梯度稀释法分离筛选玉米根表共生菌株，酶标仪测定与结晶紫染色法检测细菌生物膜的形成能力，平板菌落计数检测细菌在玉米根部的定殖量。从玉米根表分离获得270株细菌，芽孢杆菌属为优势属。结晶紫染色结果发现，生物膜形成能力强的细菌会有更明显的显色反应，细菌生物膜吸光度数值在0.065～2.533；将分离菌株按生物膜形成能力强弱分为A～E组，不同生物膜形成能力组的菌株数量与形成能力呈反比，选取的5株蜡样芽孢杆菌(Bacillus cereus)的生物膜形成能力与其在植物根表的定殖能力显著相关，并且生物膜形成能力越强的菌株定殖能力越强。综上，玉米共生细菌生物膜的形成与其在根表的定殖能力呈正相关性。

Abstract:

To study the correlation between biofilm formation ability and root surface colonization ability of maize symbiotic bacteria, the following experiments were conducted: Firstly, the strains were isolated using the gradient dilution method; secondly, the bacterial biofilm formation ability was determined by microplate reader and crystal violet staining method; thirdly, the bacterial colonization amount on maize roots was detected by plate colony counting method. A total of 270 bacterial strains were isolated from the maize root surface. The crystal violet staining results showed that bacteria with strong biofilm formation ability exhibited a more obvious color reaction, and the absorbance values of bacterial biofilms ranged from 0.065 to 2.533. The isolated strains were divided into five groups（A to E） according to the strength of their biofilm formation ability, and the biofilm formation ability of the bacteria was inversely proportional to the number of bacterial strains. The biofilm formation ability of the five selected Bacillus cereus strains was significantly correlated with their colonization ability on maize root surfaces, and the stronger the biofilm formation ability, the stronger the colonization ability of the strains. In summary, the formation of biofilms by maize symbiotic bacteria is positively correlated with their colonization ability on the root surface.