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A novel pectin‐degrading enzyme complex from Aspergillus sojae ATCC 20235 mutants
Author(s) -
MataGómez Marco A.,
Heerd Doreen,
OyangurenGarcía Iñigo,
Barbero Francis,
RitoPalomares Marco,
FernándezLahore Marcelo
Publication year - 2015
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.6864
Subject(s) - pectinase , pectin , mutant , pectin lyase , chemistry , fermentation , sugar beet , food science , enzyme , biochemistry , enzyme assay , biology , gene , horticulture
BACKGROUND In the food industry, the use of pectinase preparations with high pectin esterase (PE) activity leads to the release of methanol, which is strictly regulated in food products. Herein, a pectin‐degrading enzyme (PDE) complex exhibiting low PE activity of three Aspergillus sojae ATCC 20235 mutants (M3, DH56 and Guserbiot 2.230) was investigated. Production of exo‐/endo‐polygalacturonase (PG), exo‐polymethylgalacturonase (PMG) and pectin lyase (PL) by mutant M3 and A. sojae using two different carbon sources was evaluated in solid‐state fermentation. Finally, experimental preparations obtained from the mutants and commercial pectinases standardized to the same potency were screened for PDEs. RESULTS Mutant M3 grown on sugar beet was found to be the best producer of exo‐PG, endo‐PG, exo‐PMG and PL, with maximum yields of 1111, 449, 130 and 123 U g −1 , respectively. All experimental preparations exhibited low PE activity, at least 21.5 times less than commercial pectinases, and higher endo‐PG (40 U mL −1 ). CONCLUSION Mutant M3 was the best PDE producer using sugar beet. Mutant strains presented a PDE complex featuring high endo‐PG and very low PE activities. This novel complex with low de‐esterifying activity can be exploited in the food industry to degrade pectin without releasing methanol. © 2014 Society of Chemical Industry