Molecular identification of Pichia guilliermondii, Debaryomyces hansenii and Candida palmioleophila

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Qualidade microbiológica e ocorrência de leveduras em bebidas lácteas fermentadas, com adição de polpas de frutas, comercializada na região de São José do Rio Preto - SP

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Qualidade microbiológica e ocorrência de leveduras em polpas congeladas de frutas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Verificação das boas práticas de fabricação (BFP) e análise da qualidade microbiológica de saladas adicionada de maionese comercializadas na cidade de São José do Rio Preto - SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Qualidade físcio-química e microbiológica de refrigerantes sabor guaraná em embalagens PET-2000mL e ocorrência de leveduras

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Qualidade microbiológica e ocorrência de leveduras em diferentes amostras de queijo tipo minas frescal

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Atividade antimicrobiana de microrganismos probióticos em bebidas lácteas fermentadas

Pós-graduação em Microbiologia - IBILCE

Bebidas lácteas fermentadas: evolução da microbiota durante a fabricação, identificação de fungos leveduriformes e ação de culturas probióticas sobre os leveduriformes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Controle de Guignardia citricarpa e Penicillium digitatum em laranja com óleos essenciais e agentes de biocontrole

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Identificação e avaliação da resistência antimicrobiana de leveduras em vegetais minimamente processados

The consumption of minimally processed vegetables has been growing due to consumer demand for products easy to prepare. As it is extremely manipulated, this product can be contaminated with spoilage organisms such as yeasts, that have the ability to decrease the shelf life of food. In this sense, seeking to concerns about the resistance of microorganisms to sanitation methods for food industries and given the need for more studies of the antimicrobial power of ozone, this study aimed to isolate and identify the yeasts present in minimally processed vegetables, and check their antimicrobial resistance to sodium hypochlorite and ozone. 84 samples of minimally processed vegetables were collected. From them, 47 yeast cultures were isolated and submitted for identification and testing of resistance to sodium hypochlorite sanitizers (50, 100, 200 and 400 ppm) and ozone (0.25 and 0.5 ppm). From the total yeast isolated, 85.1% corresponds to Cryptococcus laurentii, 12.8% to Arxula adeninivorans and 2.1% to Debaryomyces hansenii var. fabryii. All of them were resistant to the sanitizers sodium hypochlorite and ozone at all concentrations tested. Given these observations, some actions must be taken during processing to avoid contamination with deteriorative microbiota.

Potential use of bioagents in the control of postharvest rot in melon

Rot caused by Fusarium pallidoroseum has had a severely negative impact on the export of melons from Brazil. Uncertainty regarding the health of the fruit due to the quiescent infection of the pathogen has led producers to use fungicides in the postharvest treatment of the fruit, thereby causing contamination and risking the health of consumers. Consequently, there is a demand for clean and safe natural technologies for the postharvest treatment of melons, including biological control. The present study aimed at evaluating bioagents for use in controlling Fusarium rot in 'Galia'melon. The following bioagents were evaluated: two isolates of Bacillus subtilis, B. licheniformis and a mixture of B. subtilis and B. licheniformis, as well as the yeasts Sporidiobolus pararoseus, Pichia spp., Pichia membranifaciens, P. guilliermondii, Sporobolomyces roseus, Debaryomyces hansenii and Rhodotorula mucilagenosa. Treatment with imazalil and water were used as controls. Two experiments were conducted in a completely randomised design with 10 replicates per treatment with four fruit per replicate; the disease incidence was evaluated in the first experiment, and the disease severity was evaluated in the second. Similarity analysis of the temporal evolution profiles of rot incidence caused by F. pallidoroseum allowed the evaluated treatments to be clustered into four groups. In the first experiment, the yeasts P. membranifaciens and D. hansenii produced results similar to that of the fungicide imazalil. The second experiment highlighted the yeasts P. guilliermondii and R. mucilaginosa. Electron microscopy studies confirmed that once applied to the fruit, the yeasts colonised the skin and damaged the pathogen mycelium; the action of the yeasts affected the mycelium of F. pallidoroseum, which had infected wounds on the fruit's surface. Bacillus spp. did not provide good disease control. These results demonstrated that yeasts have the potential to control postharvest rot caused by F. pallidoroseum in 'Galia'melon.

Fungal diversity associated with Brazilian energy transmission towers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Endophytic yeasts and filamentous fungi associated with southern Brazilian apple (Malus domestica) orchards subjected to conventional, integrated or organic cultivation

Endophytic fungi were isolated from leaves, flowers and fruit of healthy apple trees (Malus domestica, BORKH.) growing in southern Brazilian orchards under three different cultivation systems (conventional, integrated and organic), during two vegetative cycles. The greatest total number of endophytic isolates was obtained from the orchards under organic cultivation when compared to integrated and conventional cultivation systems. Filamentous fungi from the genera Colletotrichum, Xylaria and Botryosphaeria were the most frequent ones and the most representative yeast genera were Sporobolomyces, Rhodotorula, Debaryomyces and Cryptococcus. It is suggested that some isolates may be used as indicators of the different management systems. © 2005 Wiley-VCH Verlag GmbH & Co. KGaA.

Avaliação do potencial antagônico de leveduras, visando biocontrole de deterioração por penicillium expansum

Considerable losses during apple fruit storage occur due to microbiological diseases, mainly caused by Penicillium expansum, which in addition to fruit pulp deterioration produces patulin, a mycotoxin with carcinogenic and teratogenic activity. Biological control of post-harvest disease by antagonist yeasts focused on killer toxins is an appreciable alternative to the chemical fungicides, due to the low possibility of toxic residues demonstrated during fermentative processes. Twenty out of 44 yeasts (16 isolated from fruits, 10 from corn silage and 18 from laboratory anthill), showed antagonism against spores of P. expansum. The assay in solid medium pointed the strongest nutrient competition antagonism by D. hansenii strain C1 (31 mm inhibition diameter), while D. hansenii strain C7 (15 mm) showed higher antibiosis and parasitism pattern. In the following step the extracellular activity was tested performing the assay with culture supernatant in Yeast Medium agar, where C. guilliermondii P3 was more effective against conidia germination (inhibition rate of 58.15%) while P. ohmeri showed better inhibition on micelial growth (66.17%). The antibiosis showed by both yeasts could suggest probable mechanism associated with killer phenomenon, once both strains were killer positive against sensitive reference strains (S. cerevisiae NCYC 1006 and P. kluyveri CAY-15). In order to enhance the production of antifungal substance, these yeasts were cultivated with P. expansum, but the difference between culture supernatant obtained from yeasts cultivated alone and with mould was not significant (P > 0.05). The results demonstrated that the yeasts application constitute a promising tool, enhancing the biological control of P. expansum in post-harvest diseases of apple fruit.

Ocorrência de leveduras em espécies vegetais nativas da mata atlântica, Parque Estadual da Serra do Mar - Núcleo Picinguaba, São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)