Invertase production on solid-state fermentation by Aspergillus niger strains improved by parasexual recombination.
Appl Biochem Biotechnol
; 102-103(1-6): 63-70, 2002.
Article
em En
| MEDLINE
| ID: mdl-12396111
ABSTRACT
Invertase production by Aspergillus niger grown by solid-state fermentation was found to be higher than by conventional submerged fermentation. The haploid mutant strains Aw96-3 and Aw96-4 showed better productivity of various enzymes, as compared to wild-type parental strain A. niger C28B25. Here we use parasexual crosses of those mutants to increase further the productivity of invertase in solid-state fermentation. We isolated both a diploid (DAR2) and an autodiploid (AD96-4) strain, which were able to grow in minimal medium after mutation complementation of previously isolated haploid auxotrophic strains. Invertase production was measured in solid-state fermentation cultures, using polyurethane foam as an inert support for fungal growth. Water activity value (Aw) was adjusted to 0.96, since low Aw values are characteristic in some solid-state fermentation processes. Such diploid strains showed invertase productivity levels 5-18 times higher than levels achieved by the corresponding haploid strains. For instance, values for C28B25, Aw96-3, Aw96-4, DAR2, and AD96-4 were 441, 254, 62, 1324, and 2677 IU/(L x h), respectively. These results showed that genetic recombination, achieved through parasexual crosses in A. niger, results in improved strains with potential applications for solid-state fermentation processes.
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Base de dados:
MEDLINE
Assunto principal:
Aspergillus niger
/
Glicosídeo Hidrolases
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article