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Preparative and capillary isoelectric focusing for detection and identification of Aspergillus conidia in complex sample matrices
Author(s) -
Horká Marie,
Šalplachta Jiří,
Růžička Filip,
Šlais Karel
Publication year - 2018
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201800547
Subject(s) - conidium , isoelectric point , isoelectric focusing , aspergillus , chromatography , aspergillus flavus , aspergillus niger , aspergillus fumigatus , chemistry , cellulose , fungi imperfecti , capillary electrophoresis , microbiology and biotechnology , botany , biology , food science , biochemistry , enzyme
This study describes a new method for fast identification of highly hydrophobic conidia of Aspergillus species from both simple and complex matrices. The method is based on recently developed preparative isoelectric focusing in a cellulose‐based separation medium which had to be modified with respect to the highly hydrophobic surface of the conidia. Although Aspergillus conidia are colored, their zones in the cellulose bed were indicated by colored isoelectric point markers. The isoelectric point values of Aspergillus conidia were determined by capillary isoelectric focusing. Preparative isoelectric focusing was successfully used for preconcentration of individual conidia of cultivated strains of Aspergillus niger , Aspergillus fumigatus , Aspergillus flavus , and Aspergillus parasiticus , and also for separation of the conidia in a mixture. Subsequently, red pepper powder and peanuts spiked with Aspergillus niger and Aspergillus flavus conidia, respectively, were used as complex matrices. The detection limit for identification of the conidia in these complex matrices is 10 4 conidia mL −1 . The presence of conidia in the focused zones was confirmed by their subsequent analysis by capillary isoelectric focusing. Their viability was confirmed by a cultivation of the conidia extracted from the collected fractions after preparative isoelectric focusing.