Raphael Pimenta - Academia.edu (original) (raw)

Uploads

Papers by Raphael Pimenta

Research paper thumbnail of Wickerhamomyces queroliae sp. nov. and Candida jalapaonensis sp. nov., two yeast species isolated from Cerrado ecosystem in North Brazil

… of systematic and …, 2009

Research paper thumbnail of Candida azymoides sp. n., a yeast species from tropical fruits and larva (Ascomycota) of Anastrepha mucronota (Diptera: Tephritidae

Four strains of the new species Candida azymoides were isolated from larvae of Anastrepha mucrono... more Four strains of the new species Candida azymoides were isolated from larvae of Anastrepha mucronota (Diptera: Tephritidae) collected from ripe fruits of Peritassa campestris ("bacupari", Hippocrateaceae) in the state of Tocantins and from ripe fruits of Eugenia uniflora ("pitanga", Myrtaceae) collected in the state of Sergipe, Brazil. Candida azymoides is the sister species to C. azyma in the Wickerhamiella clade, in the Saccharomycetes. The type strain is Candida azymoides UFMG-R287 (CBS 10508).

Research paper thumbnail of A novel method for selecting antagonists against postharvest fruit decays originating from latent infections

Research paper thumbnail of Biological control of Penicillium italicum, P. digitatum and P. expansum by the predacious yeast Saccharomycopsis schoenii on oranges

Brazilian Journal of Microbiology, 2008

In this study we evaluated the ability of Saccharomycopsis schoenii Nadson and Krassiln (UWO-PS 8... more In this study we evaluated the ability of Saccharomycopsis schoenii Nadson and Krassiln (UWO-PS 80-91) as biocontrol agent against plant pathogenic filamentous fungi P. expansum Link (UFMG 01-2002), P. italicum Wehmer (LCP 61.1199), and P. digitatum (Pers.: Fr.) (LCP 984263, LCP 68175 and LCP 4354). S. schoenii was able to reduce disease severity in oranges inoculated with all fungi. Among the phytopathogens, P. digitatum LCP4354 was the most virulent whereas P. digitatum LCP 68175 was the most susceptible to predation. The yeast was able to survive for 21 days on the fruit surface and did not produce lesions on oranges. Production of antagonistic substances by S. schoenii was not detected using standard techniques. Our results point to the potential use of S. schoenii to control postharvest phytopathogens in fruits.

Research paper thumbnail of Yeast communities in two Atlantic rain Forest fragments in Southeast Brazil

Brazilian Journal of Microbiology, 2009

We studied the yeast communities associated with fruits, mushrooms, tree exudates, and flies of t... more We studied the yeast communities associated with fruits, mushrooms, tree exudates, and flies of the genus Drosophila, in two Atlantic Rain Forest fragments in state of Minas Gerais, Brazil. A total of 456 samples were collected from Rio Doce State Park and 142 from Ecological Station of Universidade Federal de Minas Gerais. From these samples, 608 yeast isolates were obtained, belonging to 71 different species. Among the yeasts isolated from Rio Doce State Park, 17 isolates were recovered from fruits, 12 from mushrooms, 13 from tree exudates, and 299 from Drosophila spp. In the Ecological Station of Universidade Federal de Minas Gerais, 24 isolates were recovered from fruits and 243 from Drosophila spp. Distinct communities of yeast were observed in Drosophila flies, fruits, mushrooms and tree exudates. The highest number of yeast species was recovered from Drosophila flies suggesting that flies are the natural vectors of these microorganisms.

Research paper thumbnail of Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus Galactomyces

International Journal of Systematic and Evolutionary Microbiology, 2005

Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus ... more Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus Galactomyces

Research paper thumbnail of Metschnikowia cerradonensis sp. nov., a yeast species isolated from ephemeral flowers and their nitidulid beetles in Brazil

International Journal of Systematic and Evolutionary Microbiology, 2007

A novel yeast species, Metschnikowia cerradonensis sp. nov., is described from 12 strains isolate... more A novel yeast species, Metschnikowia cerradonensis sp. nov., is described from 12 strains isolated from flowers of Ipomoea carnea and from beetles of the genus Conotelus in the Cerrado ecosystem in the region of Jalapã o, Tocantins State, Brazil. Analysis of the sequences of the rRNA gene cluster suggested that M. cerradonensis is closely related to Metschnikowia santaceciliae, Metschnikowia continentalis and an undescribed species represented by strain UWOPS 00-154.1. These species mate together but ascospores are very rarely formed, showing that they represent distinct biological species. M. cerradonensis is apparently endemic to the Cerrado ecosystem of the Jalapã o area. The type strain of M. cerradonensis is UFMG 03-T67.1 T (h + ) (=CBS 10409 T =NRRL Y-48067 T ) and the designated allotype is UFMG 03-T68.1 (h " ) (=CBS 10410=NRRL Y-48068).

Research paper thumbnail of Integrated control of Penicillium digitatum by the predacious yeast Saccharomycopsis crataegensis and sodium bicarbonate on oranges

Brazilian Journal of Microbiology, 2010

Our investigation of integrated biological control (IBC) started with an assay testing activity o... more Our investigation of integrated biological control (IBC) started with an assay testing activity of the predacious yeast Saccharomycopsis crataegensis UFMG-DC19.2 against Penicillium digitatum LCP 4354, a very aggressive fungus that causes postharvest decay in oranges. Under unfavourable environmental conditions, the yeast showed a high potential for control (39.9% disease severity reduction) of this fungus. This result was decisive for the next step, in which S. crataegensis was tested in association with sodium bicarbonate salt, a generally regarded as safe (GRAS) substance. The yeast was able to survive at different concentrations of the salt (1%, 2% and 5%), and continued to grow for a week at the wound site, remaining viable at high population for 14 days on the fruit surface. The yeast alone reduced the severity of decay by 41.7% and sodium bicarbonate alone reduced severity of decay by 19.8%, whereas the application of both led to a delay in the development of symptoms from 2 to 10 days. Ingredients of the formulations were not aggressive to fruits since no lesions were produced in control experiments.

Research paper thumbnail of Wickerhamomyces queroliae sp. nov. and Candida jalapaonensis sp. nov., two yeast species isolated from Cerrado ecosystem in North Brazil

… of systematic and …, 2009

Research paper thumbnail of Candida azymoides sp. n., a yeast species from tropical fruits and larva (Ascomycota) of Anastrepha mucronota (Diptera: Tephritidae

Four strains of the new species Candida azymoides were isolated from larvae of Anastrepha mucrono... more Four strains of the new species Candida azymoides were isolated from larvae of Anastrepha mucronota (Diptera: Tephritidae) collected from ripe fruits of Peritassa campestris ("bacupari", Hippocrateaceae) in the state of Tocantins and from ripe fruits of Eugenia uniflora ("pitanga", Myrtaceae) collected in the state of Sergipe, Brazil. Candida azymoides is the sister species to C. azyma in the Wickerhamiella clade, in the Saccharomycetes. The type strain is Candida azymoides UFMG-R287 (CBS 10508).

Research paper thumbnail of A novel method for selecting antagonists against postharvest fruit decays originating from latent infections

Research paper thumbnail of Biological control of Penicillium italicum, P. digitatum and P. expansum by the predacious yeast Saccharomycopsis schoenii on oranges

Brazilian Journal of Microbiology, 2008

In this study we evaluated the ability of Saccharomycopsis schoenii Nadson and Krassiln (UWO-PS 8... more In this study we evaluated the ability of Saccharomycopsis schoenii Nadson and Krassiln (UWO-PS 80-91) as biocontrol agent against plant pathogenic filamentous fungi P. expansum Link (UFMG 01-2002), P. italicum Wehmer (LCP 61.1199), and P. digitatum (Pers.: Fr.) (LCP 984263, LCP 68175 and LCP 4354). S. schoenii was able to reduce disease severity in oranges inoculated with all fungi. Among the phytopathogens, P. digitatum LCP4354 was the most virulent whereas P. digitatum LCP 68175 was the most susceptible to predation. The yeast was able to survive for 21 days on the fruit surface and did not produce lesions on oranges. Production of antagonistic substances by S. schoenii was not detected using standard techniques. Our results point to the potential use of S. schoenii to control postharvest phytopathogens in fruits.

Research paper thumbnail of Yeast communities in two Atlantic rain Forest fragments in Southeast Brazil

Brazilian Journal of Microbiology, 2009

We studied the yeast communities associated with fruits, mushrooms, tree exudates, and flies of t... more We studied the yeast communities associated with fruits, mushrooms, tree exudates, and flies of the genus Drosophila, in two Atlantic Rain Forest fragments in state of Minas Gerais, Brazil. A total of 456 samples were collected from Rio Doce State Park and 142 from Ecological Station of Universidade Federal de Minas Gerais. From these samples, 608 yeast isolates were obtained, belonging to 71 different species. Among the yeasts isolated from Rio Doce State Park, 17 isolates were recovered from fruits, 12 from mushrooms, 13 from tree exudates, and 299 from Drosophila spp. In the Ecological Station of Universidade Federal de Minas Gerais, 24 isolates were recovered from fruits and 243 from Drosophila spp. Distinct communities of yeast were observed in Drosophila flies, fruits, mushrooms and tree exudates. The highest number of yeast species was recovered from Drosophila flies suggesting that flies are the natural vectors of these microorganisms.

Research paper thumbnail of Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus Galactomyces

International Journal of Systematic and Evolutionary Microbiology, 2005

Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus ... more Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus Galactomyces

Research paper thumbnail of Metschnikowia cerradonensis sp. nov., a yeast species isolated from ephemeral flowers and their nitidulid beetles in Brazil

International Journal of Systematic and Evolutionary Microbiology, 2007

A novel yeast species, Metschnikowia cerradonensis sp. nov., is described from 12 strains isolate... more A novel yeast species, Metschnikowia cerradonensis sp. nov., is described from 12 strains isolated from flowers of Ipomoea carnea and from beetles of the genus Conotelus in the Cerrado ecosystem in the region of Jalapã o, Tocantins State, Brazil. Analysis of the sequences of the rRNA gene cluster suggested that M. cerradonensis is closely related to Metschnikowia santaceciliae, Metschnikowia continentalis and an undescribed species represented by strain UWOPS 00-154.1. These species mate together but ascospores are very rarely formed, showing that they represent distinct biological species. M. cerradonensis is apparently endemic to the Cerrado ecosystem of the Jalapã o area. The type strain of M. cerradonensis is UFMG 03-T67.1 T (h + ) (=CBS 10409 T =NRRL Y-48067 T ) and the designated allotype is UFMG 03-T68.1 (h " ) (=CBS 10410=NRRL Y-48068).

Research paper thumbnail of Integrated control of Penicillium digitatum by the predacious yeast Saccharomycopsis crataegensis and sodium bicarbonate on oranges

Brazilian Journal of Microbiology, 2010

Our investigation of integrated biological control (IBC) started with an assay testing activity o... more Our investigation of integrated biological control (IBC) started with an assay testing activity of the predacious yeast Saccharomycopsis crataegensis UFMG-DC19.2 against Penicillium digitatum LCP 4354, a very aggressive fungus that causes postharvest decay in oranges. Under unfavourable environmental conditions, the yeast showed a high potential for control (39.9% disease severity reduction) of this fungus. This result was decisive for the next step, in which S. crataegensis was tested in association with sodium bicarbonate salt, a generally regarded as safe (GRAS) substance. The yeast was able to survive at different concentrations of the salt (1%, 2% and 5%), and continued to grow for a week at the wound site, remaining viable at high population for 14 days on the fruit surface. The yeast alone reduced the severity of decay by 41.7% and sodium bicarbonate alone reduced severity of decay by 19.8%, whereas the application of both led to a delay in the development of symptoms from 2 to 10 days. Ingredients of the formulations were not aggressive to fruits since no lesions were produced in control experiments.