Identification of the Glutaminase Genes ofAspergillus sojaeInvolved in Glutamate Production during Soy Sauce Fermentation
| Autor: | Kotaro Ito, Yasuji Koyama, Yoshiki Hanya |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Taste
Glutamine Glutamic Acid Umami Biology Aspergillus sojae Applied Microbiology and Biotechnology Biochemistry Analytical Chemistry Glutaminase Culture Techniques Food science Molecular Biology Gene chemistry.chemical_classification Hydrolysis Organic Chemistry Glutamate receptor Soy Foods General Medicine biology.organism_classification Aspergillus Enzyme chemistry Fermentation Biotechnology |
| Zdroj: | Bioscience, Biotechnology, and Biochemistry. 77:1832-1840 |
| ISSN: | 1347-6947 0916-8451 |
| DOI: | 10.1271/bbb.130151 |
| Popis: | Glutaminase, an enzyme that catalyzes the conversion of L-glutamine to L-glutamate, enhances the umami taste in soy sauce. The Aspergillus sojae genome contains 10 glutaminase genes. In this study, we estimated that approximately 60% of the glutamate in soy sauce is produced through the glutaminase reaction. To determine which glutaminase is involved in soy sauce glutamate production, we prepared soy sauces using single and multiple glutaminase gene disruptants of A. sojae. The glutamate concentration in soy sauce prepared using the ΔgahA-ΔgahB-ΔggtA-Δgls disruptant was approximately 60% lower than that in the control strain, whereas it was decreased by approximately 20-30% in the ΔgahA-ΔgahB disruptant. However, the glutamate concentration was unchanged in the soy sauces prepared using the ΔgahA-ΔggtA-Δgls and ΔgahB-ΔggtA-Δgls disruptants. These results indicate that four glutaminases are involved in glutamate production in soy sauce, and that the peptidoglutaminase activities of GahA and GahB increase the glutamate concentration in soy sauce. |
| Databáze: | OpenAIRE |
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