有用土壤微生物之分離及其利用 第十二報 追加糖分對麩氨酸醱酵的影響 第二部 振盪培養瓶中的試驗

lsolation and Utilization of Economic Soil Microbes XII. Effect of Glucose-feeding on Glutamate Fermentation Part II. Trials on Shaken Flasks

王西華(H. H. Wang) ； 戴芳政(P. C. Tai) ； 吳光丞(K. T. Wu) ； 李南虢(N. K. Lee) ； 洪其璧(C. P. Huong)

《化學》 53年4期 (1964/12) Pp. 157-164

https://doi.org/10.6623/chem.1964022

摘要

本實驗的目的，在於探討歎麩氨酸醱酵，添加糖分所引起的糖分不連續消耗的現象，及其所發生的影響，並探討其原因。在本實驗中所用的菌株為N-12；此菌株的麩氨酸積聚量相當穩定，醱酵醪的體積，嚴格控制為50ml，醱酵最初含糖量為10%，此為茵株最好的麩氨酸積聚條件，與追加糖分與否無關。但無追加糖分的醱酵醪中的菌數，較追加糖分者為少。在醱酵21或30小時加入4%的糖，則立刻增加少量菌數。然於半連續試驗中，醱酵48小時後繼續追加數次的糖分時，菌數却逐漸減少。其原因可推測為後者缺少某種營養物質而前者則不然。在濾紙色層分析中得知，48小時前追加糖分時，有較多的乳酸及α-醪酮酸（α-KGA）積聚，反之，無追加糖分的醱酵醪中則積聚較少。由此可知，醱酵48小時前追加糖分時，可促進另一消耗糖分的代謝路線。

並列摘要

In the previous work, the authors found that a rapid discontinuous sugar consumption was taken place after sugar feeding during the tank-operation of glutamate fermentation. The purpose of the present work was focused to find the probable reason for this rapid sugar consumption and to investigate its effects on fermentation. Strain N-12 was first inoculated three times at intervals of 12 hrs into the nutrient agar, and then into the Sakaguchi flask in which the fermentation broth was controlled rigidly to 50 ml. After 12 hrs on the shaking machine at 30±1℃, a 0.5 ml-aliquot was taken into production medium, 0.5 ml of 27% urea solution added to increase the pH value, and I ml of 50 % glucose added after 12, 21, 30, 39, 48, 60, and 72 hrs. The remaining sugars were estimated according to the method of Somogyi. When sugar was fed into the initial-10% glucose broth before 48 hrs of fermentation the cell population increased a little but definitely after feeding and a rapid discontinuous sugar consumption could be found (Figs. 2 and 3), but no corresponding increment in glutamate accumulation to the increase of consumed sugar in the fed broth resulted (Table 4). On the other hand, when the sugar was fed after 48 hrs of semi-continuous fermentation a slow but definite decrease of cell population was observed after 72 hrs of fermentation (Fig. 5-B to Fig. 5-E). It seems liekly that the latter was due to nutritional deficiencies but the former not. When the sugar was fed into the broth, the paper partition chromatography on the 60 hrs broth of the former trials showed that more lactic acid and α-KGA were accumulated but they were less when not (Fig. 4). In a different aerobic condition lactate accumulation was almost the same (Fig. 4-D-G). Therefor it may be said that sugar-feeding before 48 hrs stimulates a metabolic pathway to waste the charged sugar pratically. It is concluded that the rapid, discontinuous increment of sugar consumption is resulted not by the error of systematic analysis but probably by the change of metabolic pathway to make sugar waste.