CN101386817A - Method for producing yeast single cell protein by blue algae fermentation - Google Patents

Abstract

The invention relates to a method for fermentation production of yeast single cell protein by utilization of blue algae, which belongs to the technical field of blue algae treatment. The method adopts Saccharomyces cerevisiae as a fermentation strain and takes blue algae raw materials as a nitrogen source to perform fermentation production of the yeast single cell protein, researches the influence of a carbon source, vitamin, trace elements, mineral elements, culture temperature, inoculum concentration, initial pH, dissolved oxygen and the like on the yield of yeast, and optimizes the fermentation condition, so as to finally ensure that the yeast yield reaches 6.2 grams per liter with 1 percent (dry weight) of a blue algae culture medium. The invention provides a novel method for utilizing the blue algae in the Taihu Lake with industrial application potential.

Description

A kind of method of utilizing blue algae fermentation to produce yeast single cell protein

Technical field

The present invention relates to a kind of method of utilizing Taihu Lake blue-green algae fermenting raw materials to produce yeast single cell protein, belong to blue-green algae and administer technical field.

Background technology

Blue-green algae (blue algae) is that a class evolutionary history is long, Gram-negative, atrichia, contain chlorophyll a, do not form chloroplast(id), can produce the photosynthetic prokaryotic organism of oxygen.Along with a large amount of pollutents flow into Taihu Lake, the Taihu Lake blue algae bloom was frequent in recent years.After a large amount of blue-green algaes salvaged, because Wuxi land resources is limited, blue-green algae was disposed difficulty, and blue algae fermentation production biogas utilization rate is lower, burns blue-green algae cost height, and contaminate environment.Because the blue-green algae organic content is very abundant; it contains 50% crude protein; the Phycocyanins, C-of 5%-15%; 40% polysaccharides; available blue-green algae is that fermenting raw materials is produced yeast single cell protein; the single cell protein product that obtains can be used as the protein resource and is applied to field of fodder, blue-green algae can be turned waste into wealth the protection environment like this.

Summary of the invention

The purpose of this invention is to provide a kind of ether acid blue algae is the method for nitrogen source fermentation manufacture order cell protein.

Technical scheme of the present invention: a kind of method of utilizing blue algae fermentation to produce yeast single cell protein, step is:

(1) fermentation strain: adopt Wine brewing yeast strain;

(2) pre-treatment of blue-green algae: the dry weight that Taihu Lake is salvaged is counted 2% blue-green algae and is carried out the 30min natural subsidence earlier and handle, and makes that sediment settlement gets off in the blue-green algae; Filter through filter cloth again, remove leaf impurity in the blue-green algae;

(3) blue-green algae broken wall: the blue-green algae of preparation dry weight basis 1%, handle 10min at 121 ℃, make the blue-green algae substratum;

(4) configuration substratum and culture condition: the glucose that adds weight meter 0.9% in the blue-green algae substratum of dry weight basis 1% is 11.4/1 to adjust carbon-nitrogen ratio, adds VITAMIN mother liquor 1%, after cultivating 20h, add glucose make to mass concentration be 2%-4%; Culture condition is: inoculum size is 10%-15%, and temperature is 26-30 ℃, and shaking speed is 200rpm, and liquid amount is 50mL/500mL, and pH is 6-7, and fermentation time is 35-45h;

Described VITAMIN mother liquor is in g/L: vitamins B ₁1, nicotinic acid 0.4, pyridoxol 0.4, vitamin H 0.02, calcium pantothenate 2, riboflavin 0.2, inositol 1, para-amino benzoic acid 0.2;

(5) separate: adopt the natural sedimentation separated yeast, promptly get the yeast single cell protein product.

Definite method of the best fermenting carbon source of the inventor is: the blue-green algae concentration of salvaging from Taihu Lake is 2% (dry weight), through the high temperature broken wall it is made substratum, this substratum is colloidal state, and dissolved oxygen difficulty wherein is so carry out medium optimization after it is diluted to 1%.Carbon-nitrogen ratio 5.5/1 in the blue-green algae, and the required carbon-nitrogen ratio of yeast growth is 11.4/1, adjusts carbon-nitrogen ratio so can add 0.9% glucose at 1% (dry weight) blue-green algae substratum.1% blue-green algae substratum residual sugar content is 0.26g, is 0.172g behind the fermentation 12h, and fermentation 16h residual sugar is 0.075g, and fermentation 20h is 0.069g, and fermentation 24h is 0.057g.So can add glucose after cultivating 20h, the glucose addition is respectively 0%, 2%, 4%, 6%, this moment, culture condition was, temperature is 30 ℃, and shaking speed is 200rpm, and liquid amount is 50mL/500mL, and pH is 6, and inoculum size is 10%.

The glucose yeast biomass of interpolation 4% is the highest, and the yeast cell amount reaches as high as 3.8g/L when cultivating 36h, and this moment, residual sugar was 0.169g, and glucose still has residual, and substratum may also lack other nutritive substance, can do further optimization to it.Excessive interpolation glucose may produce restraining effect.

The inventor further determines VITAMIN, the method of the addition of trace element and mineral element is: on the basis of carbon source optimizing, in substratum, add the VITAMIN mother liquor, trace element mother liquor and mineral element mother liquor, investigate its influence to fermentation, the result shows that fermentation 36h yeast output all reaches maximum, the result is for the results are shown in Table 1,2,3: add VITAMIN mother liquor 1% and can obviously improve biomass, after cultivating 36h, yeast output reaches 5g/L, and interpolation trace element and mineral element do not have obvious influence to the yeast bio amount.

The inventor has further determined leavening temperature on the basis of medium optimization, initial pH value of medium, dissolved oxygen, inoculum size the results are shown in Table 4,5,6 to fermentation result's influence, the fermentation optimum temperuture is 28 ℃, and the optimum medium initial pH value is 6, and optimum inoculation amount is 15%.Dissolved oxygen the results are shown in Figure 2 to the fermentation influence, and 500mL triangular flask liquid amount is that 25mL output is the highest, and the yeast cell amount reaches as high as 6.2g/L when cultivating 36h

Beneficial effect of the present invention: the invention provides the novel method that a kind of Taihu Lake blue-green algae with industrial application potentiality utilizes.

Description of drawings

Fig. 1. glucose is to the influence of yeast growth.

Fig. 2. air flow is to the influence of yeast growth.

Embodiment

Embodiment 1: the determining of optimum carbon source

The blue-green algae concentration of salvaging from Taihu Lake is 2% (dry weight), through the high temperature broken wall it is made substratum, and this substratum is colloidal state, and dissolved oxygen difficulty wherein is so carry out medium optimization after it is diluted to 1%.Carbon-nitrogen ratio 5.5/1 in the blue-green algae, and the required carbon-nitrogen ratio of yeast growth is 11.4/1, so can add 0.9% glucose to adjust carbon-nitrogen ratio at 1% (dry weight) blue-green algae substratum.1% blue-green algae substratum residual sugar content is 0.26g, is 0.172g behind the fermentation 12h, and fermentation 16h residual sugar is 0.075g, and fermentation 20h is 0.069g, and fermentation 24h is 0.057g.So can add glucose after cultivating 20h, the glucose addition is respectively 0%, 2%, 4%, 6%, this moment, culture condition was, temperature is 30 ℃, and shaking speed is 200rpm, and liquid amount is 50mL/500mL, and pH is 6, and inoculum size is 10%.The glucose yeast biomass of interpolation 4% is the highest, and the yeast cell amount reaches as high as 3.8g/L when cultivating 36h, and this moment, residual sugar was 0.169g, and glucose still has residual, and substratum may also lack other nutritive substance, can do further optimization to it.Excessive interpolation glucose may produce restraining effect.

Embodiment 2: VITAMIN in the substratum, the determining of trace element and mineral element

On the basis of carbon source optimizing, add the VITAMIN mother liquor in substratum, micro-mother liquor and mineral element mother liquor are investigated its influence to fermentation, the result shows that fermentation 36h yeast output all reaches maximum, the results are shown in Table 1,2,3, add VITAMIN mother liquor 1% as seen from table and can obviously improve biomass, after cultivating 36h, yeast output reaches 5g/L, and interpolation trace element and mineral element do not have obvious influence to the yeast bio amount.

VITAMIN mother liquor (g/L): vitamins B ₁1, nicotinic acid 0.4, pyridoxol 0.4, vitamin H 0.02, calcium pantothenate 2, riboflavin 0.2, inositol 1, para-amino benzoic acid 0.2;

The different VITAMIN mother liquor of table 1 addition is to the influence of yeast bio amount

The different micro-mother liquor additions of table 2 are to the influence of yeast bio amount

Table 3 different minerals matter mother liquor addition is to the influence of yeast bio amount

Embodiment 3: the determining of optimal culture condition

On the basis of medium optimization, investigate leavening temperature, initial pH value of medium and inoculum size the results are shown in Table 4,5,6 to fermentation result's influence.As seen from the table, the fermentation optimum temperuture is 28 ℃, and the optimum medium initial pH value is 6, and optimum inoculation amount is 15%.

Table 4 temperature is to the influence of yeast bio amount

Table 5 pH value is to the influence of yeast bio amount

Table 6 different vaccination amount is to the influence of yeast bio amount

Embodiment 4: dissolved oxygen is to the influence of yeast G-05 biomass in the fermented liquid

Yeast is the oxygen consumption fermented bacterium, and dissolved oxygen has considerable influence to the yeast bio amount.By changing 500mL triangular flask liquid amount and shaking bottle rotating speed and investigate the influence of dissolved oxygen to biomass.Selecting 500mL triangular flask liquid amount is 25mL, 50mL, and 75mL, 100mL, shaking speed is that 200rpm experimentizes.500mL triangular flask liquid amount is that 25mL output is the highest, and the yeast cell amount reaches as high as 6.2g/L when cultivating 36h.

Claims (1)

1, a kind of method of utilizing blue algae fermentation to produce yeast single cell protein, it is characterized in that adopting yeast saccharomyces cerevisiae is fermentation strain, is nitrogenous source with the blue-green algae raw material, the fermentative production yeast single cell protein, step is:

(1) fermentation strain: adopt Wine brewing yeast strain;

(2) pre-treatment of blue-green algae: the dry weight that Taihu Lake is salvaged is counted 2% blue-green algae and is carried out the 30min natural subsidence earlier and handle, and makes that sediment settlement gets off in the blue-green algae; Filter through filter cloth again, remove leaf impurity in the blue-green algae;

(3) blue-green algae broken wall: the blue-green algae of preparation dry weight basis 1%, handle 10min at 121 ℃, make the blue-green algae substratum;

(4) configuration substratum and culture condition: the glucose that adds weight meter 0.9% in the blue-green algae substratum of dry weight basis 1% is 11.4/1 to adjust carbon-nitrogen ratio, adds VITAMIN mother liquor 1%, after cultivating 20h, add glucose make to mass concentration be 2%-4%; Culture condition is: inoculum size is 10%-15%, and temperature is 26-30 ℃, and shaking speed is 200rpm, and liquid amount is 50mL/500mL, and pH is 6-7, and fermentation time is 35-45h;

Described VITAMIN mother liquor is in g/L: vitamins B ₁1, nicotinic acid 0.4, pyridoxol 0.4, vitamin H 0.02, calcium pantothenate 2, riboflavin 0.2, inositol 1, para-amino benzoic acid 0.2;

(5) separate: adopt the natural sedimentation separated yeast, promptly get the yeast single cell protein product.

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