KR970007200B1 - Preparation of erythritol - Google Patents

Abstract

The invention relates to a process for producing erythritol, a natural sweetener, in a high yield by aerobically culturing a varient of Trichosporonoides sp. CFC86 (KFC10791) in a medium which uses glucose, lactose, fructose or sugar as carbon source, and powder yeast, peptone or urea as nitrogen source.

Description

Method for preparing erythritol

The present invention is to cultivate aerobic trichosporonoides oedocephalis CFC86 (Trichosporonoides oedocephalis CFC 86: KFCC 10791), a microbial strain belonging to the genus Tricosporonoides in nutrient medium to produce erythritol in high yield. It is about a method.

Erythritol is a kind of natural sweetener whose main ingredient is sugar alcohol in the form of meso-Erythritol. Erythritol is a natural ingredient present in nature, and is mainly contained in mushrooms and acerolas. The sweetness level is about 80% of the sugar and is characterized by a protein-sweet sweetener that rapidly extinguishes its aftertaste. Yeristitol acts as an endothermic when dissolved to provide a cool sweetness. The processing characteristics of erythritol are small hygroscopicity and low complexation, which makes it suitable for all foods. In addition, the decay fungus Streptococcus mutans (S.mutans) is not a decay-inducing sweetener because it can not produce the acid or glucan due to the degradation of erythritol. In addition, the disadvantages of the existing sugar alcohols induce a diarrhea when ingested a lot, but intake of erythritol has a physiological characteristic is less induction of diarrhea.

Conventional erythritol manufacturing method is a method using Candida lipolytica (US Patent No. 3,756,917), a method using Torigonopsis variabilis (Japanese Patent No. 49-118889), Torula ) (European Patent 136,805) and Ouriobasidium (Aureobasidium) microbial method (Japanese Patent No. 62-247) and the like, but the strain has a long fermentation period and low culture sugar concentration ( Incubation time: 168-200 hours, Sugar concentration: 20-30%) In addition to erythritol, there are many by-products such as glycerol (Glycerol), which has a low fermentation yield (40% water).

Accordingly, it is an object of the present invention to provide a method for screening and preparing a high titer strain that can overcome the disadvantages of the conventional erythrite production method. Erythritol is produced in high yield by culturing the mutant tricosporonoides oedocephalis CFC86 (KFCC10791) of the present invention obtained by artificial mutant treatment in a nutrient-optimized medium containing a carbon source, a nitrogen source, an inorganic salt and the like ( Incubation time 120 hours, sugar concentration 20-40%, yield 40% -50%).

Hereinafter, the present invention will be described in more detail.

The mutant strain of the present invention has the following strain characteristics; It is an incomplete fungus whose morphology changes from yeast to mycelium by asexual reproduction depending on environmental conditions. In other words, initially, colonies aggregate to grow into pellets of round shape, grow into a grayish white yeast, and then grow from yeast to mycelium as time passes.

Carbon sources that can be used in the culture of the high titer mutant of the present invention include glucose, lactose, fructose, sugar, and the like. Powdered yeast, peptone, urea, and the like can be used as organic and inorganic nitrogen sources. The culture temperature of the mutant strain of the present invention is suitable in the range of 20-30 ℃, preferably in the range of 30-32 ℃. The optimum pH for culturing is near neutral, and erythritol is produced by incubating with aeration for 5-6 days.

Trichosporonoides oedocephalis ATCC 16958, the parent strain of the cultivation at optimal conditions, is difficult to produce erythritol at 10% glucose and 10% glucose, whereas the yield is 10%. Phosphorus glycerol is produced 20% and its production amount is very high.

On the contrary, KFCC10791, a high titer strain according to the present invention, was able to produce erythritol in high yield even at a high concentration of 10% or more glucose, as well as to produce erythritol up to 40% of glucose concentration, and by-product glycerol was produced at 1% or less. In particular, when cultured at a glucose concentration of 20%, erythritol is produced in the culture medium at a yield of about 50% and glycerol of 0.5% or less is produced. The lower the amount of glycerol, the higher the crystallization yield during the purification process. The purification process can use a conventional purification method.

The present invention is explained in more detail in the following examples.

Example 1

The parent strain Tricosporonoides oedocephalis ATCC 16958 was incubated for 100-120 hours in germination medium (40% glucose or 40% sugar, 1% powdered yeast), and then centrifuged to separate homologs. The suspension was further suspended in sterilized 0.1 M magnesium sulfate solution and then irradiated with ultraviolet light for 20 minutes (0.1-1% survival) to induce mutations. It is then plated in agar preservation medium (20% glucose or 20% sugar, 1% powdered yeast, 0.1% urea, 2% agar) and incubated at 30 ° C for 24-48 hours, followed by flask culture of separated colonies to produce erythritol. The highly mutant tricosphoronoides oedocerapis CFC 86 of the present invention was prepared, and deposited on May 25, 1993, to the Korean spawn association (KFCC 10791).

Take 100 micrograms of cells obtained from the agar preservation medium culture (10% glucose or 10% sugar, 0.5% powdered yeast, 0.5% powdered urea, 0.1% urea, 0.2% ammonium sulfate, magnesium sulfate hydrate 0.05). %, Potassium dihydrogen phosphate 1.5%, iron sulfate hexahydrate 0.02%, potassium hydrogen phosphate 0.9%, pH 6.0-6.4) 50ml flask containing aseptically aseptically. Then incubated with shaking (200 rpm) for 120 hours at 30 ℃. The yield of erythritol after the completion of culture was 43% when glucose was used as the carbon source, and 37.4% when sugar was used as the carbon source.

Example 2

Fermentation It was carried out as in Example 1 except that the concentration of glucose in the culture medium was added 10-40%.

Table 1 shows the amount of erythritol produced according to the glucose concentration change.

TABLE 1

Example 3

Fermentation The culture was carried out in the same manner as in Example 1 except that 10% glucose was added and the culture temperature was 25-30 ° C.

Table 2 shows the amount of erythritol produced according to the culture temperature change.

TABLE 2

Claims (2)

A method for producing erythritol, characterized in that erythritol is produced in a high yield by culturing aerobically, KFCC10791, which is CFC86, which is a microorganism strain belonging to the genus Tricosphoronoides, in a culture medium. KFCC 10791, which belongs to Tricosporonoides and is a tricosporonoides oedocerapis CFC86, a microbial strain with high erythritol-producing ability.