Journal of Nutrition & Food Sciences
Open Access
ISSN: 2155-9600
ISSN: 2155-9600
Cledir Santos, Marta Simoes, Rodrigo Maldonado, Alex Seguel and Nelson Lima
Universidad de La Frontera, Chile
Edge Hill University, UK
University of Minho, Braga, Portugal
Posters & Accepted Abstracts: J Nutr Food Sci
Ochratoxin A and fumonisin B2 are mycotoxins that represent serious concerns for food safety. Fungal strains used in biotechnological process should previously be analysed while their potential to produce such kind of secondary metabolites. Moreover, the long-term preservation of fungal strains can be a factor of stress for the production of mycotoxins by fungi. The objective of this study was to evaluate the effect of freeze-drying and long-term storage on the biotechnological potential of Aspergillus strains by a polyphasic approach. 21 selected strains of Aspergillus section nigri were preserved by freeze-drying and aged by accelerated storage at 37�?°C in the dark for two different periods: two weeks and 4 four weeks. In this work morphological characteristics, mycotoxins and enzymes production, MALDI-TOF MS spectra and ERIC/PCR were used as part of the polyphasic approach to evaluate the biotechnological characteristics of these strains before and after freeze-drying preservation and accelerated storage. Phenotypical changes were observed in aged freeze-dryed strains, nevertheless these changes were suitable for the biotechnological use of these strains, since production of ochratoxin A and fumonisin B2 was maintained or decreased after freeze-drying preservation and the activity of polysaccharide-hydrolytic enzymes (CMCase, xylanase, pectinase and mannanase) was also maintained or increased after freeze-drying preservation. MALDI-TOF MS spectra showed a higher number of peaks (which makes fungal identification more accurate) for 53% and 61% of the strains aged for two weeks and four weeks respectively. These findings provide evidence that freezedrying preservation is a suitable option to preserve biotechnologically relevant Aspergillus strains.
Email: cledir.santos@ufrontera.cl