JPH0416160B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a method for producing L-glutamic acid by fermentation. The present inventors mixed pineapple molasses and cane molasses or starch saccharified liquid from 1:4 to 1:1.
By using pineapple pulmolasses and cane molasses or starch saccharified liquid together as carbon sources at a ratio within the range of 1 to 1, it is possible to obtain a yield higher than that theoretically calculated when both are used together. I learned that L-glutamic acid is produced at a certain rate. This invention was completed as a result of further research based on this knowledge. That is, this invention provides pineapple pulmolasses and cane molasses or starch saccharified liquid such that the ratio of pineapple pulmolasses and cane molasses or starch saccharified liquid is in the range of 1:4 to 1:1. This is a method for producing L-glutamic acid by a fermentation method, which is characterized by culturing L-glutamic acid-producing bacteria in combination as a carbon source. Pineapple pulmolasses is obtained by adding water to the processing residue after extracting the juice from pineapple fruit, squeezing the juice, and then heating and concentrating it. Cane molasses is obtained by adding slaked lime to the pressed juice of sugar cane, performing so-called liming, filtering the resulting syrup, concentrating the resulting syrup, and removing the sugar and concentrating the remaining liquid again. Starch saccharified liquid is corn, tapioca, honeydew,
Water is added to starchy raw materials such as potatoes to emulsify them,
It is obtained by (1) adding an acid such as hydrochloric acid or sulfuric acid to the emulsion for hydrolysis, neutralizing it with an alkali such as sodium hydroxide, and (2) adding liquefied amylase and then saccharifying amylase for reaction. , a liquid whose main component is glycol. There are many examples of L-glutamic acid producing bacteria used in the present invention, which are so-called coryneform bacteria. Some examples are shown below. Brevibacterium deivalicatum
ATCC 14020 Brevibacterium flavum ATCC 14067 Brevibacterium lactofamentum
ATCC 13869 Corynebacterium acetoacid film
ATCC 13870 Corynebacterium glutamicum ATCC 13032 Microbacterium ammonia film
ATCC 15354 Pineapple pulmolasses and cane molasses or starch saccharified liquid may be mixed in advance at a ratio of 1:4 to 1:1 and then mixed with other medium components,
It may be mixed separately with other medium components. The medium used in the present invention may be a normal medium containing medium components commonly used in L-glutamic acid fermentation, except for containing the above-mentioned specific carbon source. There is no need to adopt a method that is particularly different from conventional methods for culturing L-glutamic acid producing bacteria. During cultivation, pineapple molasses and cane molasses or starch saccharification solution are mixed at 1:4 to 1:1.
It may be additionally added to the medium so that the ratio is as follows. Example 1 Table 1 shows cane molasses (CM) or starch saccharified liquid (GL) and pinenut plum molasses (PM).
Five types of sugar solutions (A to E) were prepared by mixing in the proportions shown below.

[Table] Separately, a solution (S1) having the composition shown in Table 2 and a solution (S2) having the composition shown in Table 3 were prepared. Solution (S1) was used when CM and PM were used together, and solution (S2) was used when GL and PM were used together.

【table】

[Table] 50 ml of sugar solution (A to E) and 250 ml of solution (S1) or solution (S2) were mixed to prepare 300 ml of five types of media. Initial culture medium (total volume 300ml) for experimental plots 1 to 5 was added to 1
The mixture was poured into a fermenter and sterilized by heating at 115°C for 10 minutes. This was inoculated with Brevibacterium lactofermentum ATCC13869, which had been cultured in advance.
Culture was carried out at 31.5°C with aeration and stirring while maintaining the pH at 7.8 with ammonia gas. During culture, from the point when the sucrose concentration in the medium fell below 3%, the sugar solution was added to the medium little by little by adding sugar solution A to experimental area 1 and B to experiment group 2, and increasing the sucrose concentration from 2 to 3%. 4%
and cultured for 36 hours. The amount of sugar solution added was unified to 80 ml in each experimental group. During the culture, when a predetermined amount of bacteria was reached, the surfactant Tween 60 was added to the medium at a concentration of 0.6%. The fermentation results obtained are shown in Tables 4 and 5. Experimental area 2 where CM or GL and PM were used together
Regarding No. 5, the calculated yield calculated assuming that the sugar yield is the weighted average of the sugar yield in the case of CM, GL, or PM alone is also shown. The difference between the experimental value and the calculated value is
This is the synergistic effect of mixed use of CM or GL and PM.

【table】

[Table] Example 2 Five types of sugar solutions (F to J) were prepared by mixing CM or GL and PM in the proportions shown in Table 6.

[Table] Separately, a solution (S3) having the composition shown in Table 7 and a solution (S4) having the composition shown in Table 8 were prepared. Solution (S3) was used when CM and PM were used together, and solution (S4) was used when GL and PM were used together.

【table】

【table】

[Table] 100 ml of sugar solution (F to J) and 200 ml of solution (S3) or solution (S4) were mixed to prepare five 300 ml media. The culture media for experimental groups 1 to 5 (total volume: 300 ml) were poured into a 1-volume fermenter and sterilized by heating at 120° C. for 10 minutes. The sterilized medium was inoculated with Corynebacterium glutamicum ATCC13032, which had been cultured in advance, and cultured under aeration and agitation while maintaining the pH at 7.8 with ammonia gas. During the culture, when a predetermined amount of bacteria was reached, the surfactant Tween 60 was added at a concentration of 0.3% based on the volume of the medium. The amount of glutamic acid produced and the sugar yield obtained during 32 hours of culture are shown in Tables 9 and 10, and the calculated yields for Experimental Groups 2 to 5 were compared in the same manner as in Example 1.

【table】

[Table] Example 3 CM or GL and PM were mixed in the proportions shown in Table 11 to prepare five types of sugar solutions (K to O).

[Table] Separately, a solution (S5) having the composition shown in Table 12 and a solution (S6) having the composition shown in Table 13 were prepared. Solution (S5) was used when CM and PM were used together, and solution (S6) was used when GL and PM were used together.

【table】

【table】

[Table] The amount of glutamic acid produced and the sugar yield obtained during 35 hours of culture are shown in Table-14 and Table-15. In addition, for Experimental Groups 2 to 5, calculations were made in the same manner as in Examples 1 and 2. The yield was compared.

【table】

[Table] As shown in the above examples, pineapple molasses and cane molasses or starch saccharified liquid are mixed in 1:
When pineapple pulmolasses and cane molasses or starch saccharified liquid are used together as carbon sources at a ratio ranging from 4 to 1:1, the yield is higher than the theoretically calculated yield when both are used together. It was found that L-glutamic acid was produced in high yield.

[Brief explanation of drawings]

Figures 1 to 6 are Table-4 and Table-4 in the specification.
5. The results shown in Table 9, Table 10, Table 14 and Table 15 are shown respectively. In the figure, the solid line ×――× indicates the sugar yield when using 100% of cane molasses (CM) or starch saccharification liquid (GL) and the yield of 100% of pineapple molasses (PM).
This shows the theoretical value, which is a straight line connecting the yields based on sugar when used.

Claims (1)

[Claims] 1 Pineapple pulmolasses and cane molasses or starch saccharified liquid are used as carbon sources so that the ratio of pineapple pulmolasses and cane molasses or starch saccharified liquid is in the range of 1:4 to 1:1. A method for producing L-glutamic acid by a fermentation method, which comprises culturing L-glutamic acid-producing bacteria in combination.