In submerged-liquid fermentation, seven key parameters were assessed using one-factor-at-a-time to obtain the highest GABA yield using an industrial soy sauce koji Aspergillus oryzae strain NSK (AOSNSK). AOSNSK generated maximum GABA at 30 °C (194 mg/L) and initial pH 5 (231 mg/L), thus was able to utilize sucrose (327 mg/L of GABA) for carbon source. Sucrose at 100 g/L, improved GABA production at 646 mg/L. Single nitrogen sources failed to improve GABA production, however a combination of yeast extract (YE) and glutamic acid (GA) improved GABA at 646.78 mg/L. Carbon-to-nitrogen ratio (C8:N3) produced the highest cell (24.01 g/L) and GABA at a minimal time of 216 h. The key parameters of 30 °C, initial pH 5, 100 g/L of sucrose, combination YE and GA, and C8:N3 generated the highest GABA (3278.31 mg/L) in a koji fermentation. AOSNSK promisingly showed for the development of a new GABA-rich soy sauce.

在淹没液体发酵中，使用工业酱油曲曲米曲霉NSK（AOSNSK），一次使用一个因素评估了七个关键参数，以获得最高的GABA产量。AOSNSK在30°C（194 mg / L）和初始pH 5（231 mg / L）时产生最大GABA，因此能够利用蔗糖（327 mg / L GABA）作为碳源。100 g / L的蔗糖可提高646 mg / L的GABA产量。单一氮源无法改善GABA的产生，但是酵母提取物（YE）和谷氨酸（GA）的组合可提高GABA的浓度为646.78 mg / L。碳氮比（C8：N3）在216小时的最短时间内产生了最高的细胞（24.01 g / L）和GABA。在30°C，初始pH 5、100 g / L蔗糖，YE和GA的组合以及C8：N3的关键参数中，GABA最高（3278.31 mg / L）。曲发酵。AOSNSK有望展示出一种富含GABA的新型酱油的开发。