CHANGES IN SELECTIVITY OF GAMMA-AMINOBUTYRIC ACID FORMATION EFFECTED BY FERMENTATION CONDITIONS AND MICROORGANISMS RESOURCES

Abstract

In this study we observe the effect of fermentation conditions and resources of microorganisms for production of γ-aminobutyric acid (GABA). The content of produced GABA depends on various conditions such as the amount of precursor, an addition of salt, enzyme and the effect of pH. The highest selectivity of GABA (74.0 %) from the precursor (L-monosodium glutamate) has been determinate in the follow conditions: in the presence of pre-cultured microorganisms from Encián cheese in amount 1.66 % (w/v) the source of microorganisms/volume of the fermentation mixture, after the addition of 0.028 % (w/v) of CaCl2/volume of the fermentation mixture, 100 μM of pyridoxal-5-phosphate (P-5-P) and the GABA precursor concentration in the fermentation mixture 2.6 mg ml-1 in an atmosphere of gas nitrogen. Pure cultures of lactic acid bacteria increased the selectivity of GABA by an average of 20 % compared with bacteria from the path of Encián cheese.