Reversion by calcium of a yeast-like development to the original filamentous form, of the 10V10 5-fluorocytosine-sensitive mutant of Aspergillus niger
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Data
2005-09-01
Autores
Goulart, Rosangela de Carvalho [UNESP]
Marin, José Moacir
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ISSN da Revista
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Editor
Sociedade Brasileira de Microbiologia
Resumo
Alguns fungos filamentosos apresentam o fenômeno de dimorfismo, sendo que as alterações da estrutura morfológica podem induzir alterações metabólicas. A linhagem de Aspergillus niger 10v10, produtora de ácido cítrico foi submetida à ação mutagênica da radiação ultravioleta selecionando mutantes sensíveis ou resistentes ao antifúngico 5-fluorocitosina (5-FC). Os mutantes selecionados como sensíveis a 5-FC apresentaram uma alteração morfológica com desenvolvimento leveduriforme. Nestes mutantes foram avaliados o efeito da alteração de pH, a adição de sais (KH2PO4, NH4NO3, MgSO4e MnCl2), a presença de estabilizadores osmóticos, cloreto de cálcio, e o seu efeito sobre a reversão morfológica e a produção de ácido. A reversão morfológica para a forma filamentosa ocorreu apenas na presença de CaCl2 (500mM) para as linhagens mutantes 1 e 2, enquanto que a produção de ácido ocorreu nas duas formas, leveduriforme e filamentosa.
Some filamentous fungi present the phenomenon of dimorphism, their morphological structure alterations being capable of inducing metabolism changes. The Aspergillus niger strain 10v10, a producer of citric acid, was submitted to the mutagenic action of ultraviolet irradiation which respectively selects mutants sensitive or resistant to the antifungi agent 5 fluorocytosine (5-FC). 5-FC sensitive mutants presented a morphological alteration to a yeast-like form. The effects of pH changes, addition of salts (KH2PO4, NH4NO3, MgSO4 and MgCl2), the presence of osmotic stabilizers, as well as of calcium chloride, on morphological reversal and acid production were studied. Morphological reversal to the filamentous form was observed only in the presence of CaCl2 (500mM) for the mutants strains 1 and 2, while the acid production occurred in both, yeast-like and filamentous forms.
Some filamentous fungi present the phenomenon of dimorphism, their morphological structure alterations being capable of inducing metabolism changes. The Aspergillus niger strain 10v10, a producer of citric acid, was submitted to the mutagenic action of ultraviolet irradiation which respectively selects mutants sensitive or resistant to the antifungi agent 5 fluorocytosine (5-FC). 5-FC sensitive mutants presented a morphological alteration to a yeast-like form. The effects of pH changes, addition of salts (KH2PO4, NH4NO3, MgSO4 and MgCl2), the presence of osmotic stabilizers, as well as of calcium chloride, on morphological reversal and acid production were studied. Morphological reversal to the filamentous form was observed only in the presence of CaCl2 (500mM) for the mutants strains 1 and 2, while the acid production occurred in both, yeast-like and filamentous forms.
Descrição
Palavras-chave
Aspergillus niger, 5-fluorocitosina, leveduriforme, cálcio, produção de ácido, dimorfismo, Aspergillus niger, 5-fluorocytosine, yeast-like, calcium, acid production, dimorphism
Como citar
Brazilian Journal of Microbiology. Sociedade Brasileira de Microbiologia, v. 36, n. 3, p. 301-306, 2005.