RU2036231C1 - Whey-base ferment for food ethanol production - Google Patents

Abstract

FIELD: ethanol production. SUBSTANCE: ferment has a mixture of two species of lactose-fermenting yeast - Kluyveromyces lactis and Kluyveromyces marxianus. Preferable ratio of indicated yeast species is 1:1. Use of ferment proposed ensures to obtain 9.56-10% alcohol of parent whey volume. EFFECT: increased yield of ethanol. 1 tbl

Description

 The invention relates to the microbiological, dairy industry and can find application in non-waste milk processing technology, especially in the production of protein products (cheese, cottage cheese, casein).

 A known method of obtaining according to the American patent (see International application 085/01064, 1985, C 12 P 7/06), where it is used for fermentation of serum yeast of the genus Kluyveromyces species K. frange, as a result of which the process is long and low organoleptic characteristics of the finished product .

 The aim of the invention is to obtain a new starter culture with high efficiency to produce ethanol from whey (not lower than 87% of theoretical), with a low percentage of fermentation by-products (fusel oils, aldehydes, esters), and their sublimation temperature differs significantly from ethanol. This makes it possible to easily and quickly rectify raw ethanol obtained by fermenting milk sugar (lactose) with the proposed yeast, which includes 30-40 strains of lactobacilli of the genus Kluyveromyces.

 These yeast strains were isolated from koumiss, kefir, tarasun and other dairy products in various regions of Europe and Asia (Kalmykia, Tatarstan, the southern Volga region, Central Asian republics), China, Mongolia, India, Nepal, Bangladesh, Afghanistan, Iran, Iraq, etc. .

These yeast strains and in general are able to develop at a temperature of 15-35 ^{° C} (optimum 28-30 ° ^C) and synthesized basic yeast metabolic products carbon dioxide and ethanol.

 The isolated strains at Irkutsk State University and the Altai Territory KPL of the food industry for species were determined by the determinant of the Kregera yeast, as a result of which the genus Kluyveromyces species K. lactis and K. marxianus were assigned to them according to the International Systematics.

 Of the strains of these species in a 1: 1 ratio, a multi-strain starter culture was made, which was also submitted to the All-Union Collection of Industrial Microorganisms of the Institute number VKPM U-2034.

 Most of the strains of lactobacillus strains of yeast are in the collection of the Altai State Food Processing and Production Laboratory.

 Kluyveromyces yeast cells are round and oval, sometimes elongated. Vegetative propagation by multilateral budding. There may be primitive pseudomycelia, there is no true mycelium. Colonies are usually pasty. A film may form on liquid media, but it cannot be dry, powdery, or creeping. Asks are formed predominantly from vegetative diploid cells without immediately preceding conjugation. When maturing spores, the bags do not open. Ascospores are round or slightly oval, colorless, smooth. Many species of this kind ferment carbohydrates well and do not use nitrites at all.

 Yeast was cultured only on solid media. The properties of the cultures were determined on the following media: malt wort with a concentration of 10% CB; serum agar bf; Wednesday Saburo.

The cultivation temperature of 30 ^about With, the duration of 48 hours

 The biochemical properties of crops are characterized by the fact that in addition to the main products of fermentation (ethanol and carbon dioxide), fusel oils, aldehydes and ethers accumulate in nutrient media (especially liquid ones), the amount and ratio of them depends on the individual characteristics of the culture. Leave the culture with the lowest content of these substances.

 Standard Description Kluyveromyces lactis.

Growth in malt extract: after 3 days at ²⁸ ° C, cells usually spheroidal, ellipsoidal, cylindrical or sometimes (2,0-6,6 x 3.0-8.0) microns and reproduce by budding occurring singly, in pairs, and sometimes small bunches or in the form of an agglutinated mass. Amoeboid cells may form. A precipitate forms and sometimes a ring, islands or a thin film. After a month, a precipitate and ring forms at room temperature. Usually a film is present.

 Growth on malt agar: in a month at room temperature, the line culture acquires a color from brownish-cream to creamy gray, sometimes slightly pinkish, flat and quite overgrown, smooth, sometimes broken into sectors or somewhat warty, shiny or sometimes quite dull. The edge is clean, wavering or lobiform.

 Ascospore formation: conjugation immediately precedes bag formation, or diploid vegetative cells directly transform into bags. Bags quickly disappearing. One to four spheroidal or ellipsoidal ascospores are formed on the bag. Mature astroscopes usually contain fat globules and are quickly released from bags, tending to agglutinate. Spore-forming strains are usually heterothallic.

 All sugars of a small set of carbohydrates are fermented, except for inulin, and do not always ferment maltose, sucrose, raffinose. Assimilates from a large set all carbohydrate compounds except 1-arabinose, D-ribose, 1-ramnose, erythrital, inositol, liminic acid and does not always assimilate the compounds of maltose, raffinose, 1-xylose and ribite.

 Assimilation of nitrate: no.

 Growth on Vitamin Free Medium: None.

 50% (w / w) growth of glucose-yeast extract agar: none.

Growth at ³⁷ ° C: + or
Typical strain (neotype): CB 683 isolated by Allen and Thornley from expanded cheese.

 Standard Description Kluyveromyces marxianus.

Growth in malt extract: 3 days at ²⁸ ° C, the cells are rounded from ellipsoidal to cylindrical (2,0-6,0h3,0-10,0) microns, reproduced by budding, exist singly, in pairs, or rarely in short circuits. Pseudomycelia usually forms to a greater or lesser extent. A precipitate forms and sometimes a weak ring. After a month, the sediment persists. A ring may be present, sometimes there are islets or a light pellicle (thin film).

 Growth on malt agar: after a month at room temperature, the line culture is oily, painted in a cream or brownish-cream color, sometimes pinkish, flat and rather sprawling, sometimes somewhat elevated in the center, smooth or somewhat covered with grooves or sectors with grooves, sparkling or dull. The field can be oscillating or lobiform, sometimes bordered by pseudomycelia.

 Daiman plate culture on agar from a decoction of cornmeal: pseudomycelia usually forms abundantly and often develops better under anaerobic conditions. Pseudomycelium is highly branched. Sometimes blastospores can be organized into small bundles located along filamentous cells.

 The formation of ascospores: conjugation may precede the formation of a bag, or diploid vegetative cells can be directly transformed into bags (asci). Asuka quickly disappearing. From one to four sickle-shaped or kidney-shaped astroscors are formed on one asc. Released ascospores are prone to agglutination. Ascospores are observed on 2% malt extract agar, Um agar and the commonly used sporulation medium.

 All sugars ferment a small set of carbohydrates, except for maltose. From a large set, it assimilates all carbon compounds except maltose, trehalose, soluble starch, 1-ramnose, erythol, and inositol.

 Assimilation of nitrate: no.

 Growth in a vitamin-free environment: no.

 50% (w / w) growth of glucose-yeast extract agar: none.

Growth at ³⁷ ° C +
Typical strain (neotype) CBS 712, obtained in 1922

 Preparation of laboratory starter culture is carried out on an agar medium, but it is also possible on a liquid. For this, media are used: serum agar BF and wort agar (1: 1).

 On a nutrient medium, 2 types of cultures are seeded at the age of two days, Kluyveromyces lactie and Kluyveromyces marxinus, 10-15 strains of each species grown separately for each strain.

Sowing on Petri dishes is done in equal proportions (1 loop of each strain) and cultivated at a temperature of 28-30 ^about C for two days.

 With the daily development of sourdough, a set of (new batch) strains are replaced by their new set from the museum's production collection. Lactobacillus strains of the genus Kluyveromyces (species K. lactis and K. martianus) are included in the production starter culture (about 100 strains).

After culturing each Petri dish wash saline into the mattress 1.5 liter of the same nutrient medium and cultured for another two days at 30 ° ^C. After that mattresses saline wash (100-150 mL per mattress) and aseptically filtered through cheesecloth from all mattresses to the total capacity.

The finished leaven is cooled to 4-6 ^{° C} and maintained at this temperature until use, i.e. before preparing the production of sourdough. Such a starter culture contains n˙10 ⁸ (n> 1) viable yeast cells.

 The resulting sourdough is controlled by a microbiological preparation. The presence of foreign bacteria (IBD, spore, Escherichia coli) is not allowed in the starter culture.

Production ferment is prepared on pasteurized clarified whey according to OST 10-02-02-3-87 by fermenting it with 5% laboratory ferment and culturing at 30 ^about C for 1-2 days.

 PRI me R. In this example, we consider the result of the fermentation of milk cheese-free protein-free whey with the ferment of lactobacilli yeast of the genus Kluyveromyces of two species K. lactis and K. marsianus in various proportions. In all cases of the example there were equal conditions.

 Serum volume 40 l (flag).

Sourdough 3%
Fermentation time 48 hours

Fermentation temperature 28-30 ^o C.

The initial acidity of the serum is 31 ± 1 ^about T.

The final acidity of the serum (end of fermentation) 65 ± 2 ^about T.

Sourdough was made up of different collections:
From the All-Union Collection of Industrial Microorganisms (VKPM):
a) view. K. lactis strain F-1 U-2040, F-4 U 2036 and the species K.marxianus strains F-6 U-2042, F-8 U-2041;
b) type K. lactis strains F-1 U-2040, F-3 U-2039, F-4 U-2037, F-5 U-2035, F-6 U-2037, F-7 U-2038 and type K.marxianus strain F-6 U-2042;
c) K. lactis strains F-5 U-2035, F-6 U-2037 from the collection of the State Communist Party of Food Industry of the Altai Territory;
d) species K.lactis strains F-10, F-20 and species K. marxianus A-10, F-20;
d) species K. lactis strains F-10, F-20, F-30, F-40 and species K. marxianus strain F-10;
f) species K. lactis strains F-15, F-25, F-35 and species K. marxianus strain F-40.

From different collections (VKPM and GKPL Altai)
g) the species lactis strains F-1 U-2040, F-4 U-2036 and the species marxianus strains F-10, F-20.

 The data obtained are given in the table.

Considering the data in the table, we can conclude:
1. Ferment prepared for fermentation of whey with yeast strains of the species K. lactis and K. marxianus from the VKPM and GKPL collection of the Altai food industry, gives a finished product that meets GOST for food purposes (GOST-5962-67).

 2. Ferment, composed of yeast species K. lactis and K. marxianus in various proportions, gives a product that does not go beyond the food product, the yield of the finished product, the yield rate and transparency only slightly change.

 3. It is preferable to obtain data on the leaven compiled on strains of K. lactis and K. marxianus, in equal proportions.

 4. Ferment obtained on strains of K. lactis and separately on strains of K. marxianus gave the finished product with a good yield, but it was inferior in organoleptic to the product obtained on the ferment using two types of cultures.

Claims (1)

 LEVERAGE FOR PRODUCTION OF FOOD-ETHANOL BASED ON MILK SERUM, containing Kluyveromyces lactobacilli yeast, characterized in that a mixture of Kluyveromyces lactis and Kluyveromyces marxianus yeast is used from Kluyveromyces yeast.

Images