RU2538390C2 - Method of obtaining sugar-containing hydrolysates for production of biofuel (bioethanol) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to field of alcohol industry, namely to method of obtaining hydrolysates from Jerusalem artichoke for production of bioethanol. Method of obtaining sugar-containing hydrolysates from Jerusalem artichoke includes washing raw material, its milling and hydrolysis. Hydrolysis is carried out in medium of acetate buffer at pH 4.5-5.0 under action of own inulinases of Jerusalem artichoke in combination with preparations cellovirydine G20x and pectofoetidine G20x, taken in ratio 1:1.

EFFECT: invention makes it possible to increase degree of hydrolysis of Jerusalem artichoke biomass and output of sugars in must after hydrolysis for production of biofuel.

1 tbl, 2 ex, 1 dwg

Description

The invention relates to the alcohol industry, and in particular to a method for producing hydrolysates from Jerusalem artichoke for the production of biofuels (bioethanol). Jerusalem artichoke (or earthen pear) is a perennial plant originating from North America. It is a valuable fodder plant, widely used as a food and industrial plant. It is widely enough cultivated in the USA, France, Great Britain, Sweden, Norway, and also in Russia. Jerusalem artichoke tubers contain valuable polysaccharides, such as fructosans, including inulin 45-80.0%, cellulose 2.3-6.4% and pectins - up to 5.9% of absolutely dry substances (a.s.w.) during hydrolysis of which carbohydrates are fermented into alcohol.

A known method for the production of ethyl alcohol from Jerusalem artichoke (RF patent No. 2161652, published January 10, 2001), selected for the prototype, including grinding Jerusalem artichoke tubers, obtaining wort by hydrolysis of the ground mass by the action of its own inulinases of raw materials activated by introducing Ca ^{+ 2} ions into the medium in the form of sulfate, asepticization of wort with the use of the antibiotic nisin, fermentation with industrial yeast obtained by gradual transfer to media with a decrease in the proportion of the traditional starch-containing component in them.

The disadvantages of this method include the low sugar yield due to the incomplete hydrolysis of tuber biomass under the action of raw material inulinases that are not able to hydrolyze cellulose and pectins.

The objective of the invention is to develop a new method for producing sugar-containing hydrolysates for the production of biofuels (bioethanol).

The technical result of the present invention is to increase the degree of hydrolysis and sugar yield in the wort after hydrolysis.

The technical result is achieved by the fact that in the method for producing sugar-containing hydrolysates for the production of biofuels (bioethanol), characterized in that the washing, grinding of Jerusalem artichoke tubers is carried out, according to the invention, the ground mass is hydrolyzed in an acetate buffer with a pH of 4.5-5.0 under the action of proprietary inulinases of raw materials activated by introducing Ca ²⁺ ions into the medium with the addition of a mixture of preparations celloviridin G20x and pectofoetidin G20x taken in a 1: 1 ratio.

The method is as follows. Jerusalem artichoke is washed, crushed, the crushed raw materials are mixed with a solution of preparations celloviridin G20x and pectofoetidin G20x in 0.1 M acetate buffer with a pH of 4.5-5.0 and a calcium sulfate salt is added. If necessary, the pH of the medium is additionally adjusted to 4.5-5.0, preferably with 0.1 M acetic acid and hydrolyzed at a temperature of 50 ° C for 2 hours. Next, the hydrolyzate from Jerusalem artichoke is cooled to 22-24 ° C, a solution of nisin, industrial yeast are introduced for asepsis and sent to fermentation.

The invention is illustrated in Fig. 1, which shows the dynamics of the formation of sugars (excluding free sugars in raw materials) during the hydrolysis of Jerusalem artichoke under the action of a complex of raw material inulases activated with Ca ^{2+ ions} , a mixture of celloviridin G20x and pectofoetidine G20x after inulinase inactivation, as well as under the action a complex of inulinases of raw materials together with a mixture of preparations celloviridin G20x and pectofoetidine G20x taken in a 1: 1 ratio. The specific rates of sugar formation at the initial stage of hydrolysis were respectively 3.7 × 10 ^-2 , 12.6 × 10 ^-2 and 31.8 × 10 ^-2 mg / min × mg protein. Comparison of the obtained data shows that the speed of hydrolysis of Jerusalem artichoke under the action of a new multi-enzyme composition consisting of a complex of Jerusalem artichoke hydrolases and a mixture of celloviridin 120x and pectofoetidin G20x taken in a 1: 1 ratio is not determined by a simple addition of the hydrolysis rates of the individual complexes, but is the result of mutual amplification their actions.

The mechanism of action of the new multi-enzyme composition is as follows: pectinases of the drug pectofoetidin G20x destroy the pectin of the cell walls of Jerusalem artichoke biomass and increase their accessibility to the action of celloviridine G20x. As a result of this, a faster cytolysis of biomass cells occurs and a transition of a solution of bound carbohydrates and inulin, which is destroyed by a complex of Jerusalem artichoke's own inulinases. In general, this leads to an increase in the degree of hydrolysis of Jerusalem artichoke biomass and the output of fermentable sugars.

The effectiveness of different enzyme preparations and their compositions, estimated by the specific rates of sugar formation during the hydrolysis of Jerusalem artichoke (in terms of glucose), are shown in table 1.

Table 1 The drug / composition The specific rate of hydrolysis, mg / min × mg protein Celloviridin G20x 2.8 × 10 ^-2 Pectofoetidine G20x 2.2 × 10 ^-2 Pectomacerin G3x 2.2 × 10 ^-2 Glukavamorin G20x 2.3 × 10 ^-2 Celloviridin G20x - Pectomacerin G3x (1: 1) 4.3 × 10 ^-2 Celloviridin G20x - Glucavamorin G20x (1: 1) 4.5 × 10 ^-2 Pectofoetidin G20x - Pectomacerin G3x (1: 1) 3.3 × 10 ^-2 Pectofoetidine G20x - Glucavamorin G20x (1: 1) 3.1 × 10 ^-2 Celloviridin G20x - Pectofoetidin G20x (2: 1) 4.8 × 10 ^-2 Celloviridin G20x - Pectofoetidin G20x (1: 2) 4.3 × 10 ^-2 Celloviridin G20x - Pectofoetidin G20x (1: 1) 12.6 × 10 ^-2

Example 1 (prototype). To prepare the hydrolyzate, 77.4 g of washed Jerusalem artichoke tubers with a polysaccharide content of 21% and a moisture content of 76% are crushed to particles no larger than 3 mm, then mixed with water in a ratio of 1: 0.5 and 0.01% CaSO ₄ by weight of Jerusalem artichoke is added . Enzymatic hydrolysis is carried out at a natural pH of the Jerusalem artichoke medium for 2 hours at 55 ° C. The degree of hydrolysis is 75.6%, the sugar yield is 63.7 mg / g a.s.

Example 2. To prepare a hydrolyzate, 77.4 g (100 ml) of washed Jerusalem artichoke tubers with a polysaccharide content of 21% and a moisture content of 76% are crushed to particles no larger than 3 mm, then mixed with 50 ml of a 0.6% solution of the mixture of celloviridine preparations G20x and pectofoetidine G20x (1: 1 by weight) in 0.1 M acetate buffer with a pH of 4.5-5.0, add 0.01% CaSO ₄ by weight of Jerusalem artichoke and carry out enzymatic hydrolysis for 2 hours at 50 ° C. The degree of hydrolysis is 92.2%, the sugar yield is 919.4 mg / g a.s.

Claims (1)

A method of producing sugar-containing hydrolysates for the production of bioethanol, characterized in that they wash, grind Jerusalem artichoke tubers and carry out hydrolysis of the crushed mass in an acetate buffer medium with a pH of 4.5-5.0 under the action of proprietary inulinases activated by introducing Ca ^{+ 2} ions into the medium , with the addition of a mixture of drugs celloviridin G20x and pectofoetidin G20x, taken in a ratio of 1: 1.

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