Assessment of the antifungal activity of Spirulina platensis phenolic extract against Aspergillus flavus

Abstract

The production of safe food has stimulated the search for natural substances that possess antifungal activity. The indirect methods of estimating fungal biomass are based on the measurement of glucosamine, ergosterol and protein -typical compounds produced during the development of biomass. The aim of the study was to assess the effect of the phenolic extract from Spirulina platensis on the production of structural compounds in Aspergillus flavus, in order to identify its action on fungal inhibition. The Spirulina platensis methanolic extracts presented 1.15 mg phenolic compound/g Spirulina platensis, which showed an antifungal effect against Aspergillus flavus, inhibiting the glucosamine production up to 56%. Therefore, it may be employed as natural defense when food protection is necessary.Index terms: Phenolic inhibitors, antifungal property, glucosamine, protein, ergosterol. RESUMOA produção de alimentos seguros tem estimulado a busca por substâncias naturais que possuem atividade antifúngica. Os métodos indiretos de estimativa de biomassa fúngica são baseados na medição de glucosamina, ergosterol e proteína -compostos típicos produzidos durante o desenvolvimento da biomassa. Neste estudo, objetivou-se avaliar o efeito do extrato fenólico de Spirulina platensis na produção de componentes estruturais em Aspergillus flavus, a fim de identificar seu mecanismo de ação dos fenóis na inibição fúngica. O extrato metanólico de Spirulina platensis apresentou 1,15 mg de compostos fenólicos/g Spirulina platensis, apresentando um efeito antifúngico contra Aspergillus flavus, inibindo a produção de glucosamina em até 56%. Portanto, pode ser empregado como antifúngico natural quando for necessária a proteção de alimentos.

Compostos Fenólicos Produzidos a Partir De Microalgas

“…A extração de compostos fenólicos foi realizada conforme metodologia proposta por Souza et al, (2011), com adaptações. 0,2 g de biomassa liofilizada foram homogeneizadas com 2 mL de metanol em agitador orbital a 25 °C durante 60 min a 200 rpm.…”

Can Microalgae Act as Source of Preservatives in Food Chain?

“…Phenolic compounds, proteins, essential oils, among others, can act inhibiting cell wall components such as glycosamine, chitin, ergosterol and mannoproteins, destroying the membrane integrity and hindering the entry of nutrients [4,34,35]. They can also inhibit protein and amino acids synthesis, biosynthesis of sphingolipids to interfere in the transport of electrons, making the fungal cell integrity unfeasible [36].…”

“…For example, Spirulina has well-known culture conditions and has been used in food formulations or extraction of biocomposites. Studies have shown different biological actions can be identified on components of this microalga and its antifungal and antibacterial properties have being exploited [5,34,97,98].…”

Fusarium graminearum growth inhibition mechanism using phenolic compounds from Spirulina sp

“…The hydrolyzed material was neutralized with NaOH 3 M, and reverse titration was carried out with KHSO 4 (1 g 100 mL -1 ). Finally, the colorimetric method was used for the determination of glucosamine (SOUZA et al, 2011). The absorbance units were obtained by spectrophotometry (Varian, Cary 100, California, EUA) at 530 nm, and the concentrations were established using a standard curve for glucosamine (0.01 to 0.2 g L -1 ).…”

“…Toxigenic fungal species of the Fusarium and Aspergillus families are often used to study the effect of such compounds (ZABKA; PAVELA; GABRIELOVA-SLEZAKOVA, 2011). The chemical compounds extracted from natural sources with antifungal properties include essential oils, phenolic compounds, and peptides (OLIVEIRA; BADIALE-FURLONG, 2008;PAGNUSSATT et al, 2012;SOUZA et al, 2011).…”