CN100455604C

CN100455604C - Extraction of microbiological polysaccharide-hot gel

Info

Publication number: CN100455604C
Application number: CNB2006101519266A
Authority: CN
Inventors: 詹晓北; 朱莉
Original assignee: Jiangnan University
Current assignee: Jiangnan University
Priority date: 2004-06-11
Filing date: 2004-06-11
Publication date: 2009-01-28
Anticipated expiration: 2024-06-11
Also published as: CN1939933A

Abstract

Extraction of microbial polysaccharide-thermal gel is carried out by taking fecal alkali bacterium as fermented broth, centrifugalizing to obtain deposit, washing for 4 times by deionized water, washing by alcohol, drying and crushing to obtain the final product. It costs low.

Description

The extraction process of a kind of microbial polysaccharide-Re gel

The application is June 11 2004 applying date, and application number is 200410041271.8, and what denomination of invention was the same divides an application

Technical field

The extraction process of a kind of microbial polysaccharide-Re gel belongs to technical field of bioengineering.

Background technology

Hot gel claim again to condense polysaccharide, heat coagulates polysaccharide, English Curdlan by name, but when the microorganism of the T.Harada by Osaka, Japan university in 1964, find and studied at the various petroleum components of screening metabolism.Hot gel is a kind of new microbial exocellular polysaccharide, is that main raw material produces through fermentation with the carbohydrate by Bacillus foecalis alkaligenes (Alcaligenes faecalis var.myxogene), and its molecular formula is (C ₆H ₁₀O ₅) _n, intramolecularly is connected with β-1,3 key by the glucose structural unit.Its chemical structure is as follows:

Hot gel be a kind of under neutrallty condition water-fast polysaccharide.The hot gel of exsiccant is that the fabulous nothing of a kind of flowability is smelt, tasteless white or pale powder solid, and sealing can be stablized preservation for a long time in polyethylene bag, can not lose gelling characteristics.Water insoluble, the pure and mild most of organic solvents of hot gel, but swelling can take place in it in water, can be dissolved in the basic solutions such as certain density NaOH, tertiary sodium phosphate, also be soluble in formic acid, dimethyl sulfoxide (DMSO), saturated urea soln or thiocarbamide and 25% potassiumiodide.The water suspension that heating contains hot gel forms two types gel, a kind ofly be heated to 60 ℃ and be cooled to below 40 ℃ again and form, this gel is hot reversible, and its intensity is lower, therefore character be called as low fixing glue (low-set gel) between the elasticity of the fragility of agar and gelatin; Another is heated to more than 85 ℃ and forms, and is heat irreversible, is heated to 120 ℃ and does not also melt, and this gel structure is solid and have snappiness, and it is called as high fixing glue (high-set gel).Hot gel mainly is based on the characteristic of its second kind of gel in the application of field of food.

Extracting polysaccharide from fermented liquid has a variety of methods, under lab, can remove cell and other insolubles from the fermented liquid of dilution through high speed centrifugation, through dialysis polysaccharide macro-molecular and low-molecular-weight carbohydrate and inorganic salts is separated then.As the needs higher purity, then the ion-exchange of available some form and affinity chromatography are separated polysaccharide and other micro-biomacromolecule.But in industrial production, these methods are unpractical.The research of the feasibility of carrying out from economic viewpoint points out that the cost recovery of polysaccharide product often accounts for the integral part of total cost of production.

Summary of the invention

The extraction process that the purpose of this invention is to provide a kind of microbial polysaccharide-Re gel to reduce the production cost of microbial polysaccharide, makes its market competitiveness stronger.

Technical scheme of the present invention: the fermented liquid of a strain Bacillus foecalis alkaligenes (Alcaligenes faecalis) WX-C12 heat production gel, must precipitate through centrifugal, gained precipitate with deionized water washing 4 times promptly gets hot gel raw product with small amount of ethanol washing, drying, pulverizing then.Fermented liquid must precipitate through centrifugal, and its technology is 3000～8000rpm, centrifugal 10～30min.Comprise that drying, all operations temperature of pulverizing are no more than 40 ℃.With the deionized water wash temperature is 0～10 ℃.

Therefore beneficial effect of the present invention: hot gel raw product extraction process process only washes processing with water without alkali dissolution, and hot gel-forming property is good, but thalline is not removed, somewhat lower purity, but can satisfy extensive use at aspects such as feed, building materials, chemical industry.The present invention is different from original alkaline solution to hot gel and extracts the technology of hot gel with ethanol sedimentation, can save the ethanol consumption greatly and reduce cost, and can reduce cost more than 50%.Also according to the corresponding extraction process that has provided the hot gel of raw product, purpose also is in order to reduce cost to greatest extent.

Description of drawings

The extraction schematic flow sheet of the hot gel of Fig. 1 raw product.

Embodiment

Embodiment 1. hot gel preparation of fermentation liquid

Bacterial strain Bacillus foecalis alkaligenes (Alcaligenes faecalis) WX-C12 Southern Yangtze University biotechnology institute biochemical engineering laboratory preservation and providing, this bacterial strain are open at " Wuxi Light Industry Univ.'s journal " 2001,20 (4), 347～350.

Fermention medium (g/L) glucose 50, yeast extract paste 2, NH ₄Cl 3.6, KH ₂PO ₄2, MgSO ₄7H ₂O 0.5, inorganic salt concentrated solution 10mL, pH7.0 (inorganic salt concentrated solution: FeCl wherein ₃1g, NaCl 1g, CaCl ₂1g, MnCl ₂1g, the 1L deionized water).

Utilize the 9L fermention medium, on 15L Biostat C10-3 mechanical agitator tank, adopt two-stage method (thalli growth is controlled different pH values with the product glue stage) to ferment inoculum size 5%, fermentor tank mixing speed 500rpm, ventilation is 13.5L/min. gauge pressure 0.05MPa, 30 ℃ of leavening temperatures.The NaOH strength of solution of regulating the pH value is 4N, and concentration of hydrochloric acid is 3N.Thalli growth stage pH value is controlled at about 7.0, behind the 18h pH value is transferred to about 5.6, until fermentation ends.

Fermentation initial glucose concentration 50g/L, 40h left and right sides fermented liquid glucose concn drops to 9.7g/L, adds 360g glucose during 44h, and following jar of fermentation culture 90h measures hot gel output 35.9g/L.

Embodiment 2. hot gel preparation of fermentation liquid

Bacterial strain and fermention medium are with embodiment 1.Utilize the 18L fermention medium, inoculum size 5% adopts two-stage method (thalli growth is controlled different pH values with the product glue stage) to ferment on the 25L mechanical agitator tank, fermentor tank mixing speed 300rpm, ventilation is 27L/min, gauge pressure 0.05MPa, 30 ℃ of leavening temperatures.Thalli growth stage pH value is controlled at about 7.0, behind the 21h pH value is transferred to about 5.6, until fermentation ends.

Fermentation initial glucose concentration 50g/L, glucose concn drops to below the 10g/L in the fermentation culture 43h fermented liquid, adds 720g glucose, glucose concn drops to below the 10g/L once more in the 79h fermented liquid, add 720g glucose once more, fermentation culture 110h, hot gel output 43g/L.

The extraction of the hot gel of embodiment 3. raw product

Get the 2L fermented liquid, in 5000rpm, centrifugal 15min obtains precipitation with 4 ℃ of deionized water centrifuge washings four times, and washing with alcohol is used in centrifuge dehydration then, centrifuge dehydration, and 37 ℃ of vacuum-dryings, pulverizing obtains hot gel raw product.Product property is as shown in table 1:

The hot gel raw product of table 1 character

Fermentating liquid volume (L)	The hot gel output of fermented liquid (g)	Extract dry weight (g)	Gel-strength (g/cm ²) (2% aqeous suspension)	Purity (in dextrose anhydrous)
Fermentating liquid volume (L)	The hot gel output of fermented liquid (g)	Extract dry weight (g)	Gel-strength (g/cm ²) (2% aqeous suspension)	Purity (in dextrose anhydrous)	2	71.8	72.8	1200	66.7％

This extraction process process is without alkali dissolution, and hot gel molecular triple helical conformation is not destroyed, and therefore hot gel-forming property is good, but thalline is not removed somewhat lower purity.

Claims

1, the extraction process of a kind of microbial polysaccharide-Re gel, the fermented liquid that it is characterized in that a strain Bacillus foecalis alkaligenes (Alcaligenes faecalis) WX C 12 heat production gels, must precipitate through centrifugal, gained precipitate with deionized water washing 4 times promptly gets hot gel raw product with small amount of ethanol washing, drying, pulverizing then;

Described centrifugal must the precipitation, its technology is 3000～8000rpm, centrifugal 10～30min;

Comprise that drying, all operations temperature of pulverizing are no more than 40 ℃;

The deionized water wash temperature is 0～10 ℃.