Antimicrobial activity of the edible mushroom Pleurotus eryngii(DC. ) Quél grown in liquid medium

Edible mushrooms have a number of medicinal properties and this study aimed to investigate the antimicrobial activity of Pleurotus eryngiiDPUA1816 in metabolic broths after being grown in submerged cultivation. Mycelial fragments of pure P. eryngiiculture was inoculated in sweet potato culture medium and incubated at 150 rpm for 15 days at 25°C. Pleurotuseryngiiwas also cultivated for 18 days under the same conditions, the mycelial biomass was separated by filtration for quantification. The supernatant was used in the diffusion test in agar and performed against Escherichia coliCCCD-E005, Staphylococcus aureus CCCD-S009, Pseudomonas aeruginosaCCCD-P004, Candida albicansCCCD-CC001, Candida parapsilosis CCCD-CC004 and Candida tropicalisCCCD-CC002. The samples showed no inhibitory activity against bacteria, however they showed some activity againstC. albicans(12.17 mm), C. parapsilosis(27.67 mm) and C. tropicalis(13.67 mm). After being cultivated for 18 days, P. eryngiiwas able to inhibit all yeasts after 12 days of culture, with an inhibition halo of 29.33 mm at 16 days against C. parapsilosis. This study demonstrates the antifungal potential filtered liquids from P.eryngiicultivated in purple-skinned sweet potato culture medium, which suggests the possibility of the use of this species by the pharmaceutical industry as a natural source of biological action.

Antimicrobial activity of the edible mushroom Pleurotus eryngii(DC. ) Quél grown in liquid medium

Edible mushrooms have a number of medicinal properties and this study aimed to investigate the antimicrobial activity of Pleurotus eryngiiDPUA1816 in metabolic broths after being grown in submerged cultivation. Mycelial fragments of pure P. eryngiiculture was inoculated in sweet potato culture medium and incubated at 150 rpm for 15 days at 25°C. Pleurotuseryngiiwas also cultivated for 18 days under the same conditions, the mycelial biomass was separated by filtration for quantification. The supernatant was used in the diffusion test in agar and performed against Escherichia coliCCCD-E005, Staphylococcus aureus CCCD-S009, Pseudomonas aeruginosaCCCD-P004, Candida albicansCCCD-CC001, Candida parapsilosis CCCD-CC004 and Candida tropicalisCCCD-CC002. The samples showed no inhibitory activity against bacteria, however they showed some activity againstC. albicans(12.17 mm), C. parapsilosis(27.67 mm) and C. tropicalis(13.67 mm). After being cultivated for 18 days, P. eryngiiwas able to inhibit all yeasts after 12 days of culture, with an inhibition halo of 29.33 mm at 16 days against C. parapsilosis. This study demonstrates the antifungal potential filtered liquids from P.eryngiicultivated in purple-skinned sweet potato culture medium, which suggests the possibility of the use of this species by the pharmaceutical industry as a natural source of biological action.(AU)

Nitrogen source and pH interact and modulate lipase secretion in a non-clinical strain of Candida parapsilosis

Lipases (E.C. 3.1.1.3) are serine-hydrolases, and act on long chain fatty acid ester bonds. They exhibit specific and enantioselective activities, which are desirable for many industrial applications. This study aimed at screening and optimizing the production of lipases by wild yeast strains from a variety of substrates, as well as characterizing the enzyme. An initial selection was made in oxygenated oil-supplemented minimum medium, and the enzymatic activity of the supernatant was tested over p-nitrophenyl palmitate. One-hundred and twenty-four yeast strains from different substrates were tested, and twenty-three showed significantly higher lipolytic activity (p<0.01). One yeast in particular, QU110, showed best lipase production and therefore was selected for the optimization and characterization processes. This yeast exhibits enzyme secretion in initial pH 6.0, with olive oil and tryptone as carbon and nitrogen sources, respectively. There was a strong interaction between nitrogen source and initial pH, and pH 9.0seems to inhibit enzyme secretion. The crude enzyme (cell-free supernatant) shows stability in surfactants and n-hexane, but not in ethanol or methanol. A Response Surface Model was created and optimal enzyme activity conditions were observed at 36°C and pH 8.0. The lipase is appropriate for transesterification reactions, as the enzyme is more stable in strong apolar solvents than moderately apolar ones. Also, secretion by pH was not reported elsewhere, which should be further investigated and contribute for other yeast bioprocesses as well.

Occurrence of Candida orthopsilosis in Brazilian tomato fruits (Lycopersicum esculentum Mill)

We aimed to isolate and identify yeasts found in the tomato fruit in order to obtain isolates with biotechnological potential, such as in control of fungal diseases that damage postharvest fruits. We identified Candida orthopsilosis strains LT18 and LT24. This is the first report of this yeast on Lycopersicum esculentum fruits in Brazil.

Occurrence of Candida orthopsilosis in Brazilian tomato fruits (Lycopersicum esculentum Mill)

We aimed to isolate and identify yeasts found in the tomato fruit in order to obtain isolates with biotechnological potential, such as in control of fungal diseases that damage postharvest fruits. We identified Candida orthopsilosis strains LT18 and LT24. This is the first report of this yeast on Lycopersicum esculentum fruits in Brazil.(AU)

Antifungal activity of 2-chloro-N-phenylacetamide: a new molecule with fungicidal and antibiofilm activity against fluconazole-resistant Candida spp / Atividade antifúngica de 2-cloro-N-fenilacetamida: uma nova molécula com atividade fungicida e anti-biofilme contra Candida spp. resistentes a fluconazol

In the current context of emerging drug-resistant fungal pathogens such as Candida albicans and Candida parapsilosis, discovery of new antifungal agents is an urgent matter. This research aimed to evaluate the antifungal potential of 2-chloro-N-phenylacetamide against fluconazole-resistant clinical strains of C. albicans and C. parapsilosis. The antifungal activity of 2-chloro-N-phenylacetamide was evaluated in vitro by the determination of the minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), inhibition of biofilm formation and its rupture, sorbitol and ergosterol assays, and association between this molecule and common antifungal drugs, amphotericin B and fluconazole. The test product inhibited all strains of C. albicans and C. parapsilosis, with a MIC ranging from 128 to 256 µg.mL-1, and a MFC of 512-1,024 µg.mL-1. It also inhibited up to 92% of biofilm formation and rupture of up to 87% of preformed biofilm. 2-chloro-N-phenylacetamide did not promote antifungal activity through binding to cellular membrane ergosterol nor it damages the fungal cell wall. Antagonism was observed when combining this substance with amphotericin B and fluconazole. The substance exhibited significant antifungal activity by inhibiting both planktonic cells and biofilm of fluconazole-resistant strains. Its combination with other antifungals should be avoided and its mechanism of action remains to be established.

No atual contexto de patógenos fúngicos resistentes emergentes tais como Candida albicans e Candida parapsilosis, a descoberta de novos agentes antifúngicos é uma questão urgente. Esta pesquisa teve como objetivo avaliar o potencial antifúngico da 2-cloro-N-fenilacetamida contra cepas clínicas de C. albicans e C. parapsilosis resistentes a fluconazol. A atividade antifúngica da substância foi avaliada in vitro através da determinação da concentração inibitória mínima (CIM), concentração fungicida mínima (CFM), ruptura e inibição da formação de biofilme, ensaios de sorbitol e ergosterol, e associação entre esta molécula e antifúngicos comuns, anfotericina B e fluconazol. O produto teste inibiu todas as cepas de C. albicans e C. parapsilosis, com uma CIM variando de 128 a 256 µg.mL-1, e uma CFM de 512-1,024 µg.mL-1. Também inibiu até 92% da formação de biofilme e causou a ruptura de até 87% de biofilme pré-formado. A 2-cloro-N-fenilacetamida não promoveu atividade antifúngica pela ligação ao ergosterol da membrana celular fúngica, tampouco danificou a parede celular. Antagonismo foi observado ao combinar esta substância com anfotericina B e fluconazol. A substância exibiu atividade antifúngica significativa ao inibir tanto as células planctônicas quanto o biofilme das cepas resistentes ao fluconazol. Sua combinação com outros antifúngicos deve ser evitada e seu mecanismo de ação deve ser estabelecido.