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Gene cloning, purification, and characterization of a heat-stable phytase from the fungus Aspergillus fumigatus

1997; American Society for Microbiology; Volume: 63; Issue: 5 Linguagem: Inglês

10.1128/aem.63.5.1696-1700.1997

1098-5336

Luis Pasamontes, Monika Haiker, Markus Wyss, Michel Tessier, Aaron P. van Loon,

Protein Hydrolysis and Bioactive Peptides

The finding of heat-stable enzymes or the engineering of moderately thermostable enzymes into more stable ones by random or site-directed mutagenesis has become a main priority of modern biotechnology. We report here for the first time a heat-stable phytase able to withstand temperatures up to 100 degrees C over a period of 20 min, with a loss of only 10% of the initial enzymatic activity. The gene (phyA) encoding this heat-stable enzyme has been cloned from Aspergillus fumigatus and overexpressed in Aspergillus niger. The enzyme showed high activity with 4-nitrophenyl phosphate at a pH range of 3 to 5 and with phytic acid at a pH range of 2.5 to 7.5.