Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina.
J Appl Microbiol. 2012 Jan;112(1):159-74. doi: 10.1111/j.1365-2672.2011.05182.x. Epub 2011 Nov 22.
This work was conducted to identify the antifungal compounds produced by two previously isolated Bacillus sp. strains: ARP(2) 3 and MEP(2) 18. Both strains were subjected to further analysis to determine their taxonomic position and to identify the compounds responsible for their antifungal activity as well as to evaluate the efficiency of these strains to control sclerotinia stem rot in soybean.
The antifungal compounds were isolated by acid precipitation of cell-free supernatants, purified by RP-HPLC and then tested for antagonistic activity against Sclerotinia sclerotiorum. Mass spectra from RP-HPLC eluted fractions showed the presence of surfactin C(15) , fengycins A (C(16) -C(17)) and B (C(16)) isoforms in supernatants from strain ARP(2) 3 cultures, whereas the major lipopeptide produced by strain MEP(2) 18 was iturin A C(15) . Alterations in mycelial morphology and sclerotial germination were observed in the presence of lipopeptides-containing supernatants from Bacillus strains cultures. Foliar application of Bacillus amyloliquefaciens strains on soybean plants prior to S. sclerotiorum infection resulted in significant protection against sclerotinia stem rot compared with noninoculated plants or plants inoculated with a nonlipopeptide-producing B. subtilis strain.
Both strains, renamed as B. amyloliquefaciens ARP(2) 3 and MEP(2) 18, were able to produce antifungal compounds belonging to the cyclic lipopeptide family. Our data suggest that the foliar application of lipopeptide-producing B. amyloliquefaciens strains could be a promising strategy for the management of sclerotinia stem rot in soybean.
Sclerotinia stem rot was ranked as one of the most severe soybean disease in Argentina and worldwide. The results of this study showed the potential of B. amyloliquefaciens strains ARP(2) 3 and MEP(2) 18 to control plant diseases caused by S. sclerotiorum.
本工作旨在鉴定先前分离的两株芽孢杆菌（ARP(2) 3 和 MEP(2) 18）产生的抗真菌化合物。对这两株菌株进行进一步分析，以确定其分类地位，并鉴定负责其抗真菌活性的化合物，以及评估这些菌株控制大豆菌核茎腐病的效率。
通过酸沉淀细胞上清液分离抗真菌化合物，通过反相高效液相色谱法（RP-HPLC）纯化，然后测试对核盘菌（Sclerotinia sclerotiorum）的拮抗活性。RP-HPLC 洗脱馏分的质谱显示，菌株 ARP(2) 3 培养物上清液中存在表面活性素 C(15)、丰原素 A（C(16)-C(17))和 B（C(16)) 同型物，而菌株 MEP(2) 18 产生的主要脂肽是伊枯草素 A C(15)。在芽孢杆菌菌株培养物上清液中存在脂肽时，观察到菌丝形态和菌核萌发的改变。在核盘菌感染前将解淀粉芽孢杆菌菌株施用于大豆植株的叶面，与未接种植物或接种非脂肽产生的枯草芽孢杆菌菌株的植物相比，对菌核茎腐病有显著的保护作用。
这两株菌分别被命名为解淀粉芽孢杆菌 ARP(2) 3 和 MEP(2) 18，能够产生属于环状脂肽家族的抗真菌化合物。我们的数据表明，叶面施用产脂肽的解淀粉芽孢杆菌菌株可能是一种有前途的防治大豆菌核茎腐病的策略。
菌核茎腐病是阿根廷和全球最严重的大豆病害之一。本研究结果表明，解淀粉芽孢杆菌菌株 ARP(2) 3 和 MEP(2) 18 具有控制由核盘菌引起的植物病害的潜力。
