Regulation of xylanase in Aspergillus phoenicis: a physiological and molecular approach.
Microbial xylanolytic enzymes have a promising biotechnological potential, and are extensively applied in industries. In this study, induction of xylanolytic activity was examined in Aspergillus phoenicis. Xylanase activity induced by xylan, xylose or beta-methylxyloside was predominantly extracellular (93-97%). Addition of 1% glucose to media supplemented with xylan or xylose repressed xylanase production. Glucose repression was alleviated by addition of cAMP or dibutyryl-cAMP. These physiological observations were supported by a Northern analysis using part of the xylanase gene ApXLN as a probe. Gene transcription was shown to be induced by xylan, xylose, and beta-methylxyloside, and was repressed by the addition of 1% glucose. Glucose repression was partially relieved by addition of cAMP or dibutyryl cAMP.
Rizzatti
Ana Carolina Segato
AC
Departamento de Biologia da Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, SP 14040-901, Brazil.
Freitas
Fernanda Zanolli
FZ
Bertolini
Maria Célia
MC
Peixoto-Nogueira
Simone Carvalho
SC
Terenzi
Héctor Francisco
HF
Jorge
João Atílio
JA
Polizeli
Maria de Lourdes Teixeira de Moraes
Mde L
D000595:Amino Acid Sequence; D001230:Aspergillus / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D000242:Cyclic AMP / Q000378:metabolism; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014158:Transcription, Genetic
D005656:Fungal Proteins; D000242:Cyclic AMP; D043364:Endo-1,4-beta Xylanases