Preliminary Identification of Microorganisms from Jiuqu Used for Guangdong Hakka Rice Wine and Their γ-aminobutyric Acid-producing Capacity
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
Microorganisms present in red jiuqu, wheat jiuqu, and rice jiuqu used for Guangdong Hakka rice wine fermentation were isolated and identified and γ-aminobutyric acid (GABA) production by these microorganisms was studied. The results showed that red jiuqu contained two fungal isolates, a Monascus strain and a yeast strain; wheat jiuqu contained seven fungal isolates, a Mucor strain, four Aspergillus strains, one Rhizopus strain, and one yeast strain; while rice jiuqu contained six fungal isolates, one Rhizopus strain, four Aspergillus strains, and one yeast strain. Analysis of biochemical characteristics and sequence analysis identified one of the Aspergillus strains and the yeast strain isolated from wheat jiuqu as Aspergillus oryzae and Saccharomyces cerevisiae, respectively. The isolates were cultured separately by submerged fermentation and the amount of GABA in the fermentation broth was estimated by high-performance liquid chromatography (HPLC). The results showed that all fungal isolates from red jiuqu, wheat jiuqu, and rice jiuqu could produce GABA, but they had varyed GABA production capacities. Rhizopus and several Aspergillus strains produced relatively high amount of GABA, especially Aspergillus oryzae (more than 40 mg/L), followed by a Mucor strain (34.22 mg/L). Yeast strains produced the least amount of GABA, at approximate 10 mg/L.
