Producing Strain, Gamma-aminobutyric Acid

γ- Aminobutyric acid,GABA,is a kind of non-protein amino acid which widely spread,both in the prokar-yotic creature and eukaryote in nature, It is an important in hibitory neurotran smitter of the mammals'central nervous system. It has various physiological functions to the human body. Having anti-out of gear rhythm of the heart to disorder function, influence on depressing blood-pressure , improve functions of brains, the cardiovascular conditioning,enhance memorial ability, calm nerves and improve physiological activity of role. Thus function as a new factor in the field of functional foods have broad application prospcets. It presents in animals,plants and microorganism. Some strains like lactic acid bacteria, molds and yeasts are mainly used to produce GABA. In this research,the high yields GABA-producing lactic acid bacteria was selected and cultivated and the conditions of GABA fermentation was optimized.Lactobacillus brevis Pediococcus acidilactici ,was obtained an ditsyield of GABA was 1.062g/L. A highly GABA-producing mutant UN-27 has been acquired after the UV mutagenesis, the NTG mutagenesis and the UV&NTG mutagenesis.The GABA yield detected quantitatively by automatic amino acid analyze was 5.017g/L, which was 4.72 times than the original yields.the best fermentation formula (g/L) for the optimum mutagenesis conditions are: 25cm range of UV irradiation, 20s irradiation, 0.3mg/mL final concentration, and 60 mins mutagenizing. One UN-27 positive mutation was obtained through the mutagenesis, which remained genetic stability after 10 times breeding. For higher GABA yields, the optimal ferm cntation conditions of UN-27 had been studied.Glucose 15,yeast powder 20, peptone 5, NaAc 2, MgSO₄·7H₂O 0.02 ,MnSO₄·4H₂O 0.001,NaCl 0.001,FeSO₄·7H₂O 0.001, In the initial pH 6.6, the glutamate adding amount of 2g/L, 37℃, quiet place training 3.9d, GABA can reach maximum yield 6.135g/L, start strains is nearly six times.