Screening，Identification and Optimizing of γ- Aminobutyric Acid Production in Yeast

Abstract:

A strain with capability of producing γ-aminobutyric acid was isolated from the traditional food in Xinjiang and the fermentation conditions were optimized. Non-Saccharomyce yeast were isolated and further used to screen the strain with high yield of γ-aminobutyric acid. The isolated strain was identified as Hanseniaspora uvarum XYN019 by morphology and phylogenetic analysis based on the 26S rRNA sequence. The activity of amino acid production was 2.3 times higher as compared with the original one by UV mutagenesis. The optimum mutagenesis conditions are with 30s irradiation and 10-5 concentration. The better transformation conditions as follows：initial pH 5.01，culture temperature 33.95 ℃，inoculum size 3.17% and culture time 49.17 h. In this condition，the yielding capacity of GABA by the mutant was 4.926 g/L. These results suggested that the strain can be used to produce γ-aminobutyric acid and has a higher converting capability of GABA.