SU1693054A1 - Method of producing citric acid - Google Patents

Abstract

This invention relates to biotechnology and relates to the production of citric acid by the deep method from molasses and can be used in medicine and the food industry. The aim of the invention is to increase the yield of citric acid and the possibility of recycling waste. The method consists in growing the Aspergillus niger producer fungus and fermenting citric acid under aeration conditions in a nutrient medium containing molasses, purified by passing through a three-compartment electrosorption column equipped with semipermeable membranes and a ferroceramic packing, with an electric field strength of 20 to 30 V / cm . After 5 days of fermentation on the medium with molasses in this way, citric acid removal is 11.7 kg / m day, specific activity of the mycelium is 3.1 g / g, and the mass fraction of citric acid is 81.7%. 1 ill., 1 tab. , 3, C ate C

Description

The invention relates to biotechnology and concerns the production of a deep method from citric molasses which can be used in medicine and the food industry.

The purpose of the invention is to increase the yield of citric acid and the possibility of waste disposal

The method is as follows.

In the method of producing citric acid, which includes purifying the molasses solution, preparing a nutrient medium, growing the producer on it and fermenting it with citric acid, purifying the molasses solution is carried out on a three-chamber electrosorption column with semipermeable membranes and a ferroelectric ceramic with a voltage of an electric field of 20-30 V / cm ° When using electric field strength values outside the specified limits, the yield of the target product decreases.

Data on the yield of citric acid, depending on the intensity of the electric field when cleaning molasses on the proposed method are shown in table

The electrosorption column consists of three working and two electrode chambers separated by semipermeable membranes (cellophane) for the spatial separation of the processes of electrosorption and electrodialysis. The entire volume of the working chamber is filled with a ferroelectric grain.

YU

00

about ate

.B

Zero material. The material of the electrode chambers (platinum) is chosen for reasons of its durability under anodic and cathodic polarization conditions in moderately acidic and alkaline media. The molasses solution is fed from top to bottom into the working chamber, and phosphate buffer with pH 7 is fed from bottom to top into the electrode chamber.

The drawing shows the electrosorption column.

The column includes a housing 1. equipped with chambers 2 and 3 with electrodes A and 5. The internal volume of the column b is separated from the chambers 2 and 3 by semipermeable membranes 7 with porous gaskets 8. The internal volume 6 is filled with a nozzle 9 of ferroelectric, the column is also equipped with filters 10 , connected to pump 11, detector 12, sample dispenser 13, filtrate collector 14 and power supply unit 15,

In solutions of molasses treated on an electrosorption column under certain conditions, the culture conditions of the fungus Aspergillus nlger are improved, which leads to an increase in the yield of citric acid.

This effect is complex (combines electrocoagulation, electro-sorption and electrodialysis). The advantage of the proposed method is also the elimination of chemical reagents, which allows the use of waste products without further processing for agriculture (for livestock feed, for irrigation of fields, etc.).

Example 1. Purification of molasses by a known method.

The process is carried out in a metal-glass fermenter with a stirrer with a capacity of 10 liters of a controlled plant of the type AK-210. The producer is the mold fungus A. nlger. Purification of molasses is carried out as follows. Beet molasses is diluted with hot water in a 1: 1 ratio at 80 ° C and treated with yellow blood salt at the rate of 1600 g per 300 g of molasses, and then ammonium oxalate at the rate of 3.44 g per 100 g of molasses. After treatment, the molasses solution was diluted with tap water so that the sugar concentration in it was 30 g / l. The fermentation process is carried out in three stages.

Dry spores of the producer A. niger L-1 are soaked for 6 hours in synthetic medium A4 of the following composition, g / l: sucrose 50.0; NH4N0.32.5; KH2P040.16; Md50d7N20 0.25.

Soaked spores are transferred to molasses medium for deep growing, having the following composition, g / l: sucrose

30.0; MgS04 7H20 0.25; KH2P04 0.16; ZnSO4 7H20 0.005.

The grown seed mycelium is converted into molasses nutrient medium for citric acid biosynthesis, g / l: sucrose 30.0; KH2P04 0.16; ZnS04 7H20 0.005.

The temperature mode of growing the seed mycelium is 34 ° C, the duration is 24 hours, the volume of the medium is 4.0 liters.

The temperature regime of the process of citric acid biosynthesis is 32 ° C, the volume is 6.0 l.

The seed mycelium is transferred to citric acid biosynthesis medium in an amount of Juob.%.

After 1 day, begin pouring the molasses solution with a sugar concentration of 250 g / l. Molasses for gravy is treated with yellow blood salt only at the indicated dosage.

After 3 days of fermentation, the mass fraction of citric acid is 79.0%, the volume of citric acid is 9.7 kg / m3 day. the mass of the dry mycelium is 14.5 g / l, the specific activity of the mycelium unit is 1.92 g / g.

Example 2. Cleaning molasses on the proposed method.

Beet mass, diluted with water in a 1: 1 ratio, is subjected to purification on an electrosorption column. Nozzle - granules of ferroelectric ceramics (average size 0.5 mm, electric field intensity 20 V / cm, flow rate 4 l / h). The temperature is room. From the molasses solution purified in this way, a nutrient medium is prepared for growing A. niger L-4 in the process of citric acid biosynthesis and for supplementing the molasses solution during biosynthesis.

The process of citric acid biosynthesis is carried out in three stages in accordance with Example 1. The cultivation conditions are the same as Example 1.

After 5 days of fermentation, the mass fraction of citric acid is 81.7%, the removal of citric acid is 11, kg / m3 day, the mass of the dry mycelium is 13.6 g / l, the specific activity of the mycelium is 3.1 g / g.

Waste is non-toxic. Biomass can go to livestock feed. The filtrate can be used to water the fields. The content of trace elements in the filtrate - traces, ash 1.5% by weight of molasses.

Example 3. The conditions for purification of molasses and fermentation of citric acid, as in example 2. Producer A. niger VKPM F-326 (L-5). After 5 days of fermentation, the weight fraction of citric acid is 85.8%. eat citric acid 12.4 kg / m3 day, dry mycelium 13.5 g / l, specific activity of the mycelium 3.3 g / g.

Claims (1)

The invention The method for producing citric acid, which involves growing the mushroom-producer Aspergillus nlger and fermenting citric acid under conditions of aeration in a nutrient medium containing purified molasses, ammonium nitrogen, phosphate and mineral salts, to the maximum accumulation of the target product with its subsequent separation, characterized in that, in order to increase the yield of citric acid and the possibility of recycling production waste, molasses is used in a nutrient medium, purified by passing through a three-chamber electrosorption column equipped with semipermeable membranes and ferro-ceramic nozzle, with the electric field intensity of 20-30 V / cm. 1 (p