|
|
|
|
|
Ferreira-Nozawa,Monica S.; Nozawa,Sérgio R.; Martinez-Rossi,Nilce M.; Rossi,Antonio. |
In this communication, we show that the growth of isolate H6 of the dermatophyte Trichophyton rubrum on non-buffered medium and under saturating phosphate conditions is dependent on the initial growth pH, with an apparent optimum at pH 4.0. In addition, irrespective of the initial growth pH, the pH of the medium alteredduring cultivation reaching values that ranged from 8.3 to 8.9. Furthermore, this isolate synthesized and secreted almost the same levels of an alkaline phosphatase with an apparent optimum pH ranging from 9.0 to 10.0 when grown on both low- and high-phosphate medium. Also, this alkaline phosphatase is activated by Mg2+ and is EDTA-sensitive. On the other hand, the very low levels of the enzyme retained by the mycelium grown on buffered... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Alkaline phosphatase; Ambient pH; Dermatophytes; Enzyme secretion; Trichophyton rubrum; Pi sensing. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822003000200014 |
| |
|
|
Nozawa,Sérgio R.; Thedei Jr.,Geraldo; Crott,Luciana S.P.; Barbosa,José E.; Rossi,Antonio. |
In order to investigate further the adaptive response of moulds to ambient pH, we have measured by ELISA the pho-2-encoded Pi-repressible alkaline phosphatase synthesised by Neurospora crassa. We showed that the 74A and pho-2A strains of this mould secrete similar amounts of the pho-2-encoded enzyme irrespective of ambient pH, when both the preg and pgov genes are not functional, i.e., in strains nuc-2+ growing under Pi-starvation. This suggests that pho-2, which is responsive to Pi starvation via the action of genes nuc-2, preg, pgov and nuc-1, is not a gene responsive to ambient pH and that the differential glycosylation observed for the Pi-repressible alkaline phosphatase retained by the mycelium at pH 5.6 or secreted into the growth medium at pH 8.0 is... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Alkaline phosphatase; Ambient pH; Enzyme secretion; Neurospora crassa; Pi sensing. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822002000100018 |
| |
|
|
Maccheroni Jr.,Walter; Araújo,Welington Luiz; Azevedo,João Lúcio. |
In fungi a genetic system ensures that enzymes are secreted mainly at ambient pH values corresponding to their optima of activity. Although a great deal of information has been obtained concerning this environmental response, there is a lack of studies involving phytopathogenic, endophytic and entomopathogenic fungi as well as different aspects of fungus-host interactions. This study compares in a plate-clearing assays, the effect of ambient pH in the secretion of amylase, cellulase, lipase, pectinase and protease by endophytic, phytopathogenic, and entomopathogenic isolates belonging to several species of Colletotrichum. All enzymes were secreted in a pH-dependent manner by all isolates. Endophytes and pathogens showed distinct patterns of protease... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glomerella; Enzyme secretion; Endophytes; Pathogenic fungi; PacC. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000300010 |
| |
|
|
|