Thomas Pious, Upreti Reshmi
Division of Biotechnology, Indian Institute of Horticultural Research, Hessarghatta Lake, Bangalore, India-560 089.
Open Microbiol J. 2014 Oct 31;8:95-114. doi: 10.2174/1874285801408010095. eCollection 2014.
The study was taken up to assess if the media constituents played any role in governing the variable colony characteristics or pathogenicity of the bacterial wilt pathogen, Ralstonia solanacearum cultured on the widely employed Kelman medium. The effects due to the constituents 2,3,5-triphenyl tetrazolium chloride (TTC), peptone, casein hydrolysate and glucose on colony characteristics were investigated using -80°C stored culture of strain 'NH-Av01' (race 1, biovar 3) isolated from tomato. Comparing the pigment inducing TTC from two brands, its source or mode of storage/incorporation did not impart any significant effects. The source of peptone, on the other hand, displayed striking effects on the extent of colony growth, fluidity and red pigmentation depending on type, brand or batch / lot of manufacture as documented with 20 different formulations. Significant differences in the pathogenicity of isolate derived from different peptone sources in seedling-challenge assay on tomato were observed. The observations on peptone effects were endorsed with four other isolates belonging to distinct geographic locations, crops (eggplant, chilli, ginger) or races (race 1 or 4). The peptone source did not influence the pathogen-responses in biovar tests but notably altered the pattern of lawn formation and inhibition zone development during antagonistic assays. Casein hydrolysate displayed some variable effects while glucose source had no effect. This study brings to light the significant modifying effects by the peptone-constituent in Kelman medium on the physiology of R. solanacearum and the virulence of isolate and the need to consider the source of media components during culture maintenance, host-pathogen interaction studies or microbe-microbe interaction investigations.
本研究旨在评估在广泛使用的凯尔曼培养基上培养的青枯雷尔氏菌，其培养基成分是否在决定该细菌枯萎病病原菌的可变菌落特征或致病性方面发挥任何作用。使用从番茄中分离的菌株“NH-Av01”（1号小种，3号生化变种）在-80°C保存的培养物，研究了成分2,3,5-三苯基氯化四氮唑（TTC）、蛋白胨、酪蛋白水解物和葡萄糖对菌落特征的影响。比较两个品牌的色素诱导剂TTC，其来源或储存/添加方式没有产生任何显著影响。另一方面，蛋白胨的来源对菌落生长程度、流动性和红色色素沉着表现出显著影响，这取决于20种不同配方所记录的类型、品牌或生产批次。在番茄幼苗挑战试验中，观察到来自不同蛋白胨来源的分离株在致病性上存在显著差异。对蛋白胨影响的观察结果得到了另外四个分离株的证实，这些分离株来自不同地理位置、作物（茄子、辣椒、生姜）或小种（1号或4号小种）。蛋白胨来源在生化变种测试中不影响病原菌反应，但在拮抗试验中显著改变了菌苔形成模式和抑菌圈发育。酪蛋白水解物表现出一些可变影响，而葡萄糖来源没有影响。本研究揭示了凯尔曼培养基中蛋白胨成分对青枯雷尔氏菌生理和分离株毒力的显著修饰作用，以及在培养物保存、宿主-病原体相互作用研究或微生物-微生物相互作用研究期间考虑培养基成分来源的必要性。
