Leães Fernanda Leal, Velho Renata Voltolini, Caldas Danielle Gregório Gomes, Ritter Ana Carolina, Tsai Siu Mui, Brandelli Adriano
Laboratório de Bioquímica e Microbiologia Aplicada, Instituto de Ciência e Tecnologia de Alimentos, ICTA, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Brazil.
Laboratório de Biologia Celular e Molecular, Centro de Energia Nuclear na Agricultura, CENA, Universidade de São Paulo, USP, Piracicaba, SP, Brazil.
Res Microbiol. 2016 Feb-Mar;167(2):83-9. doi: 10.1016/j.resmic.2015.10.005. Epub 2015 Nov 11.
Certain Bacillus strains are important producers of antimicrobial peptides with great potential for biological control. Antimicrobial peptide production by Bacillus amyloliquefaciens P11 was investigated in the presence of heat-inactivated cells of bacteria and fungi. B. amyloliquefaciens P11 exhibited higher antimicrobial activity in the presence of inactivated cells of Staphylococcus aureus and Aspergillus parasiticus compared to other conditions tested. Expression of essential genes related to biosynthesis of the antimicrobial peptides surfactin (sfp), iturin A (lpa-14 and ituD), subtilosin A (sboA) and fengycin (fenA) was investigated by quantitative real-time PCR (qRT-PCR). The genes lpa-14 and ituD were highly expressed in the presence of S. aureus (inactivated cells), indicating induction of iturin A production by B. amyloliquefaciens P11. The other inducing condition (inactivated cells of A. parasiticus) suppressed expression of lpa-14, but increased expression of ituD. A twofold increase in fenA expression was observed for both conditions, while strong suppression of sboA expression was observed in the presence of inactivated cells of S. aureus. An increase in antimicrobial activity was observed, indicating that synthesis of antimicrobial peptides may be induced by target microorganisms.
某些芽孢杆菌菌株是抗菌肽的重要生产者，具有巨大的生物防治潜力。在存在热灭活的细菌和真菌细胞的情况下，研究了解淀粉芽孢杆菌P11产生抗菌肽的情况。与其他测试条件相比，解淀粉芽孢杆菌P11在存在金黄色葡萄球菌和寄生曲霉的灭活细胞时表现出更高的抗菌活性。通过定量实时PCR（qRT-PCR）研究了与抗菌肽表面活性素（sfp）、伊枯草菌素A（lpa-14和ituD）、枯草芽孢杆菌素A（sboA）和丰原素（fenA）生物合成相关的必需基因的表达。lpa-14和ituD基因在存在金黄色葡萄球菌（灭活细胞）时高度表达，表明解淀粉芽孢杆菌P11诱导了伊枯草菌素A的产生。另一种诱导条件（寄生曲霉的灭活细胞）抑制了lpa-14的表达，但增加了ituD的表达。在两种条件下均观察到fenA表达增加两倍，而在存在金黄色葡萄球菌的灭活细胞时观察到sboA表达受到强烈抑制。观察到抗菌活性增加，表明抗菌肽的合成可能由目标微生物诱导。
