Nutrição e crescimento do fungo nematófago Arthrobotrys oligospora
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Data
2009-12-01
Autores
Cardoso, Eliane R.
Assis, Luiz Carlos [UNESP]
Nahas, Ely [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Grupo Paulista de Fitopatologia
Resumo
As condições de crescimento e os requerimentos nutricionais de Arthrobotrys oligospora, um fungo nematófago, foram investigados em meio líquido. O organismo foi incubado em meio sintético, a 30º C e em cultura estacionária. O perfil da curva de crescimento do fungo ajustou-se a uma equação de 3º grau, mesmo após 15 dias de incubação. A temperatura e o pH ótimos para produção de micélio foram observados a 25º C e pH 5,0, respectivamente. Contudo, não foram observadas diferenças significativas entre a produção de biomassa nas temperaturas de 25º C e 30º C ou pH 5.0 e 6.0. Várias fontes de carbono foram utilizadas pelo fungo, porém a maior produção de biomassa foi verificada com maltose e sacarose. Das fontes de nitrogênio testadas, várias proteínas (triptona, extrato de levedura, caseína, peptona e casaminoácidos) e fontes inorgânicas (nitrato de sódio e cloreto de amônio) estimularam a maior produção de biomassa. Das várias vitaminas experimentadas, o crescimento do fungo aumentou 2,2 vezes com riboflavina e 2,3 vezes com a mistura biotina e tiamina em relação ao controle, sem vitamina. de modo geral, constatou-se, após o período de incubação, que o pH inicial do meio de cultura pode aumentar até 8,4. Estes resultados sugerem que as variáveis estudadas podem ter papel importante no crescimento do organismo no solo.
The growth conditions and the nutritional requirements of Arthrobotrys oligospora, a nematophagous fungus, were investigated in liquid culture. The organism was incubated in a synthetic medium, at 30º C in a static culture. Time course of growth was adjusted to a 3º degree equation, even after 15 days of incubation. Optimal temperature and pH for mycelium production were observed at 25º C and pH 5.0, respectively. However, significant differences were not found among the biomass production at temperatures 25º C and 30º C or pH 5.0 and 6.0. Several carbon sources were used by the fungus, but the highest biomass production were attained with maltose and sucrose. of the nitrogen sources tested, several proteins (tryptone, yeast extract, casein, peptone and casaminoacids) and inorganic sources (sodium nitrate and ammonium chloride) stimulated the highest biomass yield. of the several vitamins tested, fungus growth with riboflavin enhanced 2,2 times and 2,3 times with the mixture biotin and thiamin in relation to the control, without vitamin. In general, it was verified, after the incubation period, that the initial pH of the culture may enhance for up to 8,4. These results suggest that the studied variables may play important role in the growth of the organism in soil.
The growth conditions and the nutritional requirements of Arthrobotrys oligospora, a nematophagous fungus, were investigated in liquid culture. The organism was incubated in a synthetic medium, at 30º C in a static culture. Time course of growth was adjusted to a 3º degree equation, even after 15 days of incubation. Optimal temperature and pH for mycelium production were observed at 25º C and pH 5.0, respectively. However, significant differences were not found among the biomass production at temperatures 25º C and 30º C or pH 5.0 and 6.0. Several carbon sources were used by the fungus, but the highest biomass production were attained with maltose and sucrose. of the nitrogen sources tested, several proteins (tryptone, yeast extract, casein, peptone and casaminoacids) and inorganic sources (sodium nitrate and ammonium chloride) stimulated the highest biomass yield. of the several vitamins tested, fungus growth with riboflavin enhanced 2,2 times and 2,3 times with the mixture biotin and thiamin in relation to the control, without vitamin. In general, it was verified, after the incubation period, that the initial pH of the culture may enhance for up to 8,4. These results suggest that the studied variables may play important role in the growth of the organism in soil.
Descrição
Palavras-chave
Temperature, pH, vitamin, Carbon source, nitrogen source, Temperatura, pH, vitamina, fonte de carbono, de nitrogênio
Como citar
Summa Phytopathologica. Grupo Paulista de Fitopatologia, v. 35, n. 4, p. 267-272, 2009.