Evaluation of bioactive potential of a secondary metabolite produced by Penicillium nordicum

• Autor(a) principal: Wierzbínska, Agata Karolina
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/14396
• topic: Penicillium nordicum; Cytotoxicity; Antioxidant; Antimicrobial; Bioherbicide; Domínio/Área Científica::Ciências Agrárias::Biotecnologia Agrária e Alimentar

Fungi of the genus Penicillium are promising sources of bioactive substances. Fungal strains isolated from poorly characterized habitats are currently under active investigation as potential producers of biologically active compounds. Penicillium nordicum is mostly known by its ability to produce the mycotoxin ochratoxin A in several protein- and salt-rich food matrices like processed meat and cheese, but it can also produce an array of other secondary metabolites. In a previous study, strains of this species were found to produce, under specific growth conditions, one unidentified compound in apparently big amounts, without producing ochratoxin A. The aim of the present study was to evaluate the bioactive properties of this compound in terms of antioxidant, antimicrobial, cytotoxic and phytotoxic properties. For that purpose, the fungus was grown on chorizo-based medium and the aqueous extract of the compound was used for further tests. Pestalotin was the predominant compound in the fungal extract, with questiomycin and 7-hydroxypestalotin also being found at lower concentrations, as detected by Liquid Chromatography-Mass Spectrometry (HPLC-MS/MS) based multimetabolite method. The extract did not show any cytotoxic activity in non-tumor porcine liver primary culture cells and human tumor cell lines. The antibacterial effect on human clinical isolates and antifungal effect on foodborne and environme ntal isolates was also not significant. However, it showed significant effects on seed germination as well as on root and shoot growth of tomato, lettuce, wheat and oat. The root growth inhibition ranged from 65.9% to 100%, and the shoot growth was reduced in 22.7% to 92%, being tomato the most sensitive plant. The extract can be considered as a potential bioherbicide by its phytotoxic effect, without noticeable negative effects on human and animal cells and also on the environment. Further tests on herbicidal potential are now under development.