JPH0416159B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a method for producing L-glutamic acid by fermentation. The present inventors used citrus molasses and cane molasses or starch saccharified liquid in combination as carbon sources at a ratio of 1:4 to 1:1. By doing so, L can be obtained in a higher yield than the yield calculated theoretically when both are used together.
-I learned that glutamic acid is produced. This invention was completed as a result of further research based on this knowledge. That is, in this invention, citrus molasses and cane molasses or starch saccharified liquid are mixed in a ratio of 1:4 to 1:1.
Production of L-glutamic acid by a fermentation method characterized by culturing L-glutamic acid-producing bacteria using citrus molasses and cane molasses or starch saccharified liquid as carbon sources in combination at a ratio of up to 1. It is the law. Citrus molasses is obtained by squeezing the juice from citrus fruits, adding slaked lime to the residue, mainly the peel, and performing so-called liming, and then heating and concentrating the juice. Cane molasses is obtained by adding slaked lime to the pressed juice of sugar cane, performing so-called liming, filtering the resulting syrup, concentrating it, and reconcentrating the remaining liquid after removing the sugar. 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 glucose. 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 Citrus molasses 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, but they may also be mixed separately with other medium components. good. 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 liquid. There is no need to adopt a method that is particularly different from conventional methods for culturing L-glutamic acid producing bacteria. During culturing, citrus molasses and cane molasses or starch saccharification solution may be supplemented to the medium at a ratio of 1:4 to 1:1. Example 1 Cane molasses (CM) or starch saccharified liquid (GL) and citrus molasses (SM) were mixed in the proportions shown in Table 1 to prepare five types of sugar liquids (A to E).

[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 SM were used together, and solution (S2) was used when GL and SM 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 using CM or GL and SM together
Regarding No. 5, the calculated yield calculated by assuming that the sugar yield is the weighted average of the sugar yield in the case of CM, GL, or SM 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 SM.

【table】

[Table] Example 2 Five types of sugar solutions (F to J) were prepared by mixing CM or GL and SM 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 SM were used together, and solution (S4) was used when GL and SM 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 SM 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 SM were used together, and solution (S6) was used when GL and SM 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, citrus molasses and cane molasses or starch saccharified solution are mixed so that the ratio of citrus molasses and cane molasses or starch saccharified solution is within the range of 1:4 to 1:1. It has been found that L-glutamic acid is produced in a higher yield than the theoretically calculated yield when both are used together as a carbon source.

[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% cane molasses (CM) or starch saccharified liquid (GL) and the sugar yield when using 100% citrus molasses (SM). It shows what is connected by a straight line, that is, the theoretical value.

Claims (1)

[Claims] 1 Citrus molasses and cane molasses or starch saccharified liquid are used together as a carbon source so that the ratio of citrus molasses 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.