Department of Microbiology, Laboratory of Mycotoxins and Toxigenic Fungi, University of São Paulo, São Paulo, São Paulo, Brazil.
Department of Bacteriology, Laboratory of Bacterial Physiology, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Rio de Janeiro, Brazil.
PLoS One. 2014 Apr 16;9(4):e92189. doi: 10.1371/journal.pone.0092189. eCollection 2014.
Bacterial antagonists used as biocontrol agents represent part of an integrated management program to reduce pesticides in the environment. Bacillus thuringiensis is considered a good alternative as a biocontrol agent for suppressing plant pathogens such as Fusarium. In this study, we used microscopy, flow cytometry, indirect immunofluorescence, and high performance liquid chromatography to determine the interaction between B. thuringiensis subsp. kurstaki LFB-FIOCRUZ (CCGB) 257 and F. verticillioides MRC 826, an important plant pathogen frequently associated with maize. B. thuringiensis showed a strong in vitro suppressive effect on F. verticillioides growth and inhibited fumonisin production. Flow cytometry analysis was found to be adequate for characterizing the fungal cell oscillations and death during these interactions. Further studies of the antagonistic effect of this isolate against other fungi and in vivo testing are necessary to determine the efficacy of B. thuringiensis subsp. kurstaki in controlling plant pathogens. This is the first report on the use of flow cytometry for quantifying living and apoptotic F. verticillioides cells and the B. thuringiensis Cry 1Ab toxin.
作为生物防治剂使用的细菌拮抗剂是减少环境中农药的综合管理计划的一部分。苏云金芽孢杆菌被认为是一种抑制植物病原菌（如镰刀菌）的良好生物防治剂替代品。在这项研究中，我们使用显微镜、流式细胞术、间接免疫荧光和高效液相色谱法来确定苏云金芽孢杆菌亚种 kurstaki LFB-FIOCRUZ（CCGB）257 与重要的植物病原菌玉米弯孢菌 MRC 826 之间的相互作用。苏云金芽孢杆菌对镰刀菌的生长具有很强的体外抑制作用，并抑制伏马菌素的产生。流式细胞术分析被发现足以描述这些相互作用过程中真菌细胞的振荡和死亡。有必要进一步研究该分离物对其他真菌的拮抗作用和体内试验，以确定苏云金芽孢杆菌亚种 kurstaki 对植物病原菌的控制效果。这是首次使用流式细胞术定量检测活的和凋亡的镰刀菌细胞以及苏云金芽孢杆菌 Cry 1Ab 毒素的报道。
