Nudel B C, Fraile E R
Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
Rev Argent Microbiol. 1984;16(4):209-17.
The production of L-threonine in submerged culture was studied in the following bacterial strains; Brevibacterium flavum ATCC 21269, Corynebacterium acetoacidophilum ATCC 21270, Escherichia coli ATCC 21149, E. coli NRRL 12098, E. coli NRRL 12099 and E. coli NRRL 12100. Erlenmeyer flasks with different volumetric relations liquid/recipient, were used to study the influence of the volumetric oxygen transfer rate. B. flavum reached levels of threonine of 0.72 g/l at 96 hours of culture with a volumetric relation liquid/recipient of 1:5. With a relation 1:25 the maximal level was reached at 48 hours (0.60 g/l of threonine) (Table 1). In addition to threonine this strain accumulated in the culture media glutamic acid (+/- 2 g/l), alanine or glycine and proline. With E. coli ATCC 21149 the aeration favored the production of threonine reaching levels of 0.38 g/l in six day cultures with valine and alanine at levels approximate to 2 g/l. Excepting C. acetoacidophilum, all the strains produced threonine at levels of 0.30 to 3.55 g/l (Table 5). E. coli NRRL 12098 and E. coli NRRL 12100 produced only threonine, the culture medium being free from other aminoacids. With E. coli NRRL 12098 levels of 2 g/l were attained but the production was restricted to the presence of yeast extract in the media (Table 2). E. coli NRRL 12100 was the best strain and the inoculum media influenced the production (Table 3) and the best threonine levels were reached in the best aeration conditions assayed (Table 4) with 3.55 g/l for volumetric relations 1:10 and 1.25 g/l for 1:5.
在以下细菌菌株中研究了深层培养中L-苏氨酸的生产情况：黄色短杆菌ATCC 21269、嗜乙酰酸性棒状杆菌ATCC 21270、大肠杆菌ATCC 21149、大肠杆菌NRRL 12098、大肠杆菌NRRL 12099和大肠杆菌NRRL 12100。使用具有不同液体/容器体积关系的锥形瓶来研究体积氧传递速率的影响。黄色短杆菌在液体/容器体积关系为1:5的培养96小时时，苏氨酸水平达到0.72 g/l。在关系为1:25时，在48小时达到最高水平（0.60 g/l苏氨酸）（表1）。除了苏氨酸外，该菌株还在培养基中积累了谷氨酸（约2 g/l）、丙氨酸或甘氨酸以及脯氨酸。对于大肠杆菌ATCC 21149，通气有利于苏氨酸的生产，在六天培养中苏氨酸水平达到0.38 g/l，缬氨酸和丙氨酸水平约为2 g/l。除嗜乙酰酸性棒状杆菌外，所有菌株产生的苏氨酸水平为0.30至3.55 g/l（表5）。大肠杆菌NRRL 12098和大肠杆菌NRRL 12100仅产生苏氨酸，培养基中不含其他氨基酸。对于大肠杆菌NRRL 12098，达到了2 g/l的水平，但生产仅限于培养基中存在酵母提取物的情况（表2）。大肠杆菌NRRL 12100是最佳菌株，接种培养基影响生产（表3），在测定的最佳通气条件下达到了最佳苏氨酸水平（表4），对于体积关系1:10为3.55 g/l，对于1:5为1.25 g/l。
