KR101343619B1 - A novel arthrospira platensis having high flocculation activity - Google Patents

Abstract

In the present invention, asrospyra plathesis E41K variant with improved aggregation activity ( Arthrospira) platensis E41K mutant, KCTC 12105BP) and the Asrospira plathesis E41K variant.
The Asrospira plathesis E41K variant is asrospyra plathesis NIES 39 ( Arthrospira platensis A variant obtained by treating ethyl methane sulfonate (EMS) in NIES 39) with not only good coagulation activity but also good coagulation activity even at pH 9, which is the optimum pH of the culture, Since the coagulation activity is not affected, when culturing the Asrospira plathesis E41K variant, no additional work such as pH control is required in obtaining algae, and a chemical coagulant is a source of pollution to the algae itself and the environment. It does not require the use of, and despite the low light irradiation has excellent growth activity, that is, excellent biomass production capacity, the effect will be very large industrially.

Description

Novel ARTHROSPIRA PLATENSIS HAVING HIGH FLOCCULATION ACTIVITY

The present invention relates to a novel asrospira platensis excellent in aggregation activity.

Algae are high in protein and lipids and can immobilize carbon dioxide and thus can be utilized as biomass for food, feed or fuel production. Among them, the genus Spirulina sp.) Algae are filamentous unicellular cyanobacteria that have a characteristic of proliferating in an alkaline environment rich in bicarbonate in tropical and subtropical areas.

Algae of the spirulina genus are rich in protein (60% -70%), gamma, vitamins, essential amino acids, minerals, essential fatty acids and unsaturated fatty acids such as vitamin B ₁₂ (vitamin B ₁₂ ) or provitamin A It contains a large amount of linolenic acid (gamma-linolenic acid, GLA) and is useful as a blood circulation and immune enhancing agent, and is widely used as a pet feed additive, aquaculture feed additive or health supplement food. In particular, spirulina platensis ( Spirulina platensis ) is an economically important filamentous cyanobacteria among the spirulina genus algae, also known as Arthrospira platensis . Many studies have been conducted to improve the growth conditions and culture for mass production of the spirulina platensis.

In order to use the microalgae as a biomass, in producing microalgae on a large scale, an important process along with a culturing process to improve the production of microalgae is a process of dehydrating harvested microalgae.

Separation of microalgae from microalgae incubators on a large scale industrial scale has been a challenge due to the small size and the well-diluted nature of the microalgae. Industrially, in order to produce food or fuel using microalgae, development of a process capable of efficiently separating microalgae from a microalgae incubator is required.

Flocculation is the preferred method for efficiently separating the microalgae from the incubator. The agglomeration process is particularly efficient and inexpensive for harvesting cells such as microalgae having a predetermined size or more in size and is economical in terms of centrifugation, filtration or gravity precipitation. preferred over sedimentation. In addition, there is an advantage that less energy consumption is required when performing the aggregation mode under optimal conditions.

The flocculation efficiency of the microalgae can be increased by using a flocculant. For example, it has been reported that the microalgae are aggregated using a chemical flocculant such as aluminum sulfate or iron chloride. Such a flocculant is widely used because of the economic advantages of the effective advantage and the low cost of effective coagulation efficiency improvement.

Recently, however, some chemicals of these flocculants are known to be toxic or carcinogenic and their use is limited. In addition, among the components used as the flocculant, alum and iron are known to have side effects such as remaining in the biomass and causing subsequent problems. Therefore, the method of using a chemical flocculant is limited in industrial production due to problems such as side effects.

In addition, a method of achieving effective aggregation by adjusting the pH of the culture medium to basic conditions without adding the chemical flocculant has been proposed. Specifically, in the case of Botryococcus braunii , when the pH of the culture medium is adjusted to pH 11, it was confirmed that the cells can be effectively aggregated to harvest the cells. The degree of aggregation under these conditions was found to be more effective than when using a chemical flocculant such as aluminum sulfate or a microbial flocculant such as Pestan.

However, it is not clear whether the coagulation activity can be remarkably improved only by adjusting the pH of the culture medium to basic conditions, that is, pH 11, in other microalgae such as Boturiococcus brownies.

Therefore, with regard to microalgae that are subject to mass production, there is a need for development of alternatives to replace chemical flocculants known as toxic chemicals. Recently, biodegradable, nontoxic and secondary pollution ( Bioflocculants are widely studied because they do not cause secondary pollution.

Since the wild type strain capable of producing the biocoagulant is limited, there is a method widely used in the field of biotechnology, that is, a method of developing a mutant strain capable of producing a biocoagulant by inducing mutations. Is being applied. Information on how to produce or breed microalgae mutants or microalgae mutants with excellent flocculation activity capable of producing the biocoagulant is limited.

For example, a method of using ethyl methane sulfonate (EMS) as a general method for producing mutations in microorganisms or algae is disclosed. It is known that the ethyl methane sulfonate can replace a large number of specific DNA sequences and cause random mutations. However, little has been reported to produce or obtain microalgae mutants with improved coagulation activity through chemical mutagens such as chemicals such as ethyl methane sulfonate.

The production method of the microalgae mutants with improved coagulation activity has been published in a limited way, mainly due to physical mutagens. For example, mutant sarcoma by ion implantation has been reported to show high aggregation activity in bacteria.

KR 2003-0092901 A KR 0207937 B

 Wijffels RH and Barbosa MJ, An outlook on microalgal biofuels., Science 329: 796-799 (2010)  Bilanovic D et al, Flocculation of microalgae with cationic polymers-effect of medium salinity., Biomass 17: 65-76 (1988)  Lee SJ et al, Effects of harvesting method and growth stage on the flocculation of the green alga Botryococcus braunii., Lett in Appl Microbiol 27: 14-18 (1998)  Cao Y et al, Breeding of high lipid producing strain of Geotrichum robustum by ion beam implantation., Elecronic J Biotech 1-9 (2010)  Peirui L Y et al, Screening of bioflocculant-producing strain by ion implantation and flocculating characteristics of bioflocculants., Plasma Sci and Tech 10: 394-397 (2008)

Accordingly, the present invention provides a novel asrospiran platensis ( Arthrospira ) with improved coagulation activity. It is an object to provide a variant strain derived from platensis ).

In addition, an object of the present invention is to provide a method for producing microalgae using a novel Asrospira plattensis-derived mutant strain with improved coagulation activity.

In order to achieve the above object, the present invention provides an improved agglomeration activity of Asrospyra plathesis algae ( Arthrospira platensis ), specifically Asrospira plattensis mutant strain is provided.

In addition, the present invention provides a method for producing microalgae using the agglutination strain of Asrospira plattenis.

Hereinafter, the present invention will be described in detail.

The present inventors are working to improve the flocculation activity of algae in relation to the dehydration process, which is essential in the mass production of algae, while the Asrospira platensis NIES 39 ( Arthrospira platensis) Among the variants obtained by treating NIES 39 with ethyl methane sulfonate (EMS), the Asthrospira platensis E41K mutant has excellent coagulation activity and excellent coagulation activity at pH conditions. The present invention was completed by confirming that it is maintained regardless of the addition of a chemical flocculant and has a good growth activity, that is, a good biomass production capacity despite a small amount of light irradiation.

In the present invention, the culture medium means that the nutrients required by the culture medium for cultivating the tissues of microorganisms or animals or animals are included as main ingredients, or further include additional substances in addition to the main ingredients for special purposes. Also called culture medium, incubator or culture solution. The medium may be a natural medium, a synthetic medium or a selective medium, there are solid or liquid medium depending on the properties, but is not limited thereto.

The present invention relates to an Astrophyra plathesis strain excellent in aggregation activity. Asperspira plattensis strains excellent in the aggregation activity is Asrospyra plathensis E41K variant ( Arthrospira platensis E41K mutant).

Asperspira plattenis strain excellent in the coagulation activity is wild type ( Aspiraphylla plathesis NIES 39 ( Arthrospira platensis As a variant of NIES 39), it may be a strain having improved aggregation activity as compared to the Asrospyra plathesis NIES 39.

The Asrospira plathesis E41K variant is asrospyra plathesis NIES 39 ( Arthrospira platensis NIES 39) may be a variant obtained by treating ethyl methane sulfonate (EMS).

The Asrospira Platensis E41K variant was deposited on December 16, 2011 at a biological resource center located in Yuseong-gu, Daejeon, Korea, and was given the accession number KCTC 12105BP on December 28, 2011.

The Asrospyra plathesis E41K variant is excellent in coagulation activity, significantly improved coagulation activity as compared to wild type Asrospyra plathesis NIES 39, and shows excellent coagulation activity even at pH 9, which is an optimum pH of the culture, In acidic (pH 4) and basic (pH 12) conditions, the coagulant activity is slightly increased, and the good coagulant activity is maintained even without the addition of a chemical coagulant. There is an advantage of exhibiting excellent flocculation activity without using.

In addition, the biomass production, that is, the cell dry weight, is superior to the wild type Asrospyra Platensis NIES 39, while the chloroplast content per cell weight is low, so that the high growth activity, i.e., the bio biomass, is low despite low light irradiation. It has a mass production capacity, making it suitable for mass production.

The present invention also relates to a method for producing microalgae using the Asrospira plattensis mutant strain excellent in the aggregation activity.

More specifically, the present invention relates to a method for producing microalgae comprising the step of culturing the Asrospira plattensis mutant strain excellent in the aggregation activity.

The method of producing the microalgae may further comprise the step of obtaining the Asrospira plathesis E41K variant from the culture. In this aspect, the present invention is to produce a microalgae comprising the step of culturing the asrospyra plathesis mutant strain having excellent aggregation activity in a culture medium and obtaining the asrospyra plathesis E41K variant from the culture medium. It is about how to.

Since the optimal culture pH of the Asrospira plattenis E41K variant is pH 9, and the Asrospyra plathesis E41K variant exhibits excellent aggregation activity without additional pH adjustment, the step of culturing is pH 8 to pH 10 , Preferably pH 8.5 to pH 9.5, more preferably pH 9 can be carried out by the method of incubation.

The culture solution may be cultured in a conventional medium, for example, a common medium containing a nitrogen source.

The step of obtaining the Asrospyra plathesis E41K variant may be obtained by a conventional method for obtaining algae from the algae culture, for example, centrifugation method, filtration method or gravity precipitation method may be used, flocculation activity Algae can be obtained with excellent efficiency even through a simple filtration method, etc., due to the characteristics of the excellent Asrospira plathesis E41K variant.

In addition, depending on the conditions and yield required, the pH can be adjusted to acidic (pH 5 or less or pH 4 or less) or basic (pH 10 or more or pH 12 or more), or a chemical coagulant such as aluminum sulfate, zinc sulfate or iron chloride is added. It may further comprise a step, but it can be selectively adjusted.

The mutant asrospira plattenis E41K variant according to the present invention not only has excellent coagulation activity, but also shows excellent coagulation activity even at pH 9, which is the optimum pH of the culture, compared to the wild type asrospyra plathesis NIES 39. Since the flocculating activity is not affected by the addition of the flocculant, no additional work such as pH control is required in the production of the algae, and the use of the chemical flocculant which causes pollution to the algae itself and the environment is also unnecessary. In spite of low light irradiation, it has good growth activity, that is, has good biomass production capacity, and is suitable for mass culture of algae, so the effect will be very industrially.

Figure 1 is a photograph taken by observing the wild type Asrospira platensis NIES 39 and the mutant mut41 according to an embodiment of the present invention. Figure 1a is a photograph of the stationary algae cells in the culture medium, Figure 1b is a microscopic photograph of each strain, the scale bar in the photo shows a 200 ㎛, WT means asrospyra platensis NIES 39 and, mut41 represents the mutant Asrospira plattenis E41K variant.
Figure 2 is a graph showing the coagulation activity of wild type Asrospira platensis NIES 39 and the mutant mut41 according to an embodiment of the present invention. Aggregation activity was measured at each growth stage of the cells. WT represents wild type and mut41 represents mutant.
Figure 3 is a graph showing the biomass (dry cell weight, Figure 3a) and chlorophyll (chlorophyll, Figure 3b) content of the wild type Asrospira platensis NIES 39 and the mutant mut41 according to an embodiment of the present invention, WT represents wild type and mut41 represents mutant.
Figure 4 is a graph showing the change in coagulation activity according to the pH of the wild type Asrospira platensis NIES 39 and the mutant mut41 according to an embodiment of the present invention, WT represents a wild type, mut41 represents a mutant .
Figure 5 is a graph showing the change in the coagulation activity according to the chemical coagulant of wild type Asrospira platensis NIES 39 and the mutant mut41 according to an embodiment of the present invention, WT represents a wild type, mut41 represents a mutant Indicates. FIG. 5A illustrates a case in which ferric chloride (FeCl ₃ ) is added, and FIG. 5B illustrates a case in which aluminum sulfate (Al ₂ (SO ₄ ) ₃ ) is added, and FIG. 5C is in which zinc sulfate (ZnSO ₄ ) is added. Cases, the vertical axis of the graph represents the aggregation activity (%), and the vertical axis of the graph represents the concentration (mg / l) of each chemical flocculant.

Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are only a preferred embodiment of the present invention, and the present invention is not limited by the following examples.

< Example  1> Algae Strains and Culture Preparation

Arthrospira platensis NIES 39 at the Korea Institute of Bioscience and Biotechnology NIES 39, KCTC AG30033) was distributed and incubated using SOT medium, and the culture was performed at 120 rpm, pH 9 and 35 ° C. The SOT medium is NaHCO ₃ in 1L of distilled water 16.8 g, K ₂ HPO ₄ 0.5 g, NaNO ₃ 2.5 g, K ₂ SO ₄ 1 g, NaCl 1 g, MgSO ₄ H ₂ O 0.2 g, CaCl ₂ H ₂ O 0.04 g, FeSO ₄ H ₂ O 0.01 g, Na ₂ 0.08 g EDTA, 0.03 mg H ₃ BO ₃ , 0.025 mg MnSO ₄ H ₂ O, 0.002 mg ZnSO ₄ H ₂ O, 0.0079 mg CuSO ₄ H ₂ O and 0.0021 mg Na ₂ MoO ₄ H ₂ O It was prepared by.

While culturing the strain, medium samples were taken at various time intervals to measure growth and aggregation activity, and chlorophyll and cell dry weight were measured.

< Example  2> ethyl methane Sulfonate (EMS)  Mutagenesis and Selection

To prepare mutant strains with improved coagulation activity, ethyl methane sulfonate (EMS), known as chemical mutagen, was treated for Asrospira plattensis NIES 39.

More specifically, after washing the Asrospira Platensis NIES 39 strain in the log phase with phosphate buffered saline (PBS), 1% shaking for 1 hour in a dark state of 35 ℃ EMS (Sigma, USA) was treated.

After the treatment, the treated cells were washed with distilled water to remove EMS, and treated for 24 hours in the dark at 4 ° C. Cells treated in the dark were transferred onto solid medium and incubated at 35 ° C. until colonies were produced. The colony-forming strains were isolated from the solid medium and further cultured in liquid medium.

As a result of the solid culture, about 70 colonies were formed, and among the mutant strains, mutants having the best aggregation activity were selected and named mut41 .

The results of observing the mutant strain named mut41 and wild type Asrospyra plathesis NIES 39 are shown in FIG. 1. Photographs of the strain were observed with a Leica microscope (Wetzlar, Germany) and taken with a digital camera (Canon, USA).

As shown in FIG. 1, in the case of the phenotype of the wild type and the mutant cultured in the same culture medium, large aggregation was observed in mut41 unlike the wild type (FIG. 1A). In the wild type, the cells showed a long, loose coil form as a single cell, but in mut41 cells, aggregate formation (cell aggregation) was observed, and the aggregates were observed to aggregate into a large mass (FIG. 1B).

< Example  3> Determination of growth and aggregation activity of mutants

In order to measure the growth activity and aggregation activity with the growth of the mutant mut41 , the change in optical density over time was measured. The measurement of coagulation activity is described by Lee et. The method described in al . (Lett in Appl Microbiol 27: 14-18 (1998)) was applied.

More specifically, after 3 days, 6 days, 9 days, and 12 days at 3 days intervals after the culture, the mut41 and the Asrospira platensis NIES 39 medium was collected and suspended, and then each algal culture suspension (10 ml) was placed in a cell culture tube (Falcon) and the algal culture suspension was stirred for 1 minute. After stirring for 1 minute, it was allowed to stand for 1 hour to stabilize, inducing aggregation of algal cells.

After this time elapsed, aliquots of cells were removed from the upper layer and the absorbance was measured at 520 nm. The result of measuring the absorbance is shown in FIG. 2. In addition, the aggregation activity (%) was calculated by the following formula (1). The results calculated by the above formula are shown in FIG. 2. The results shown in FIG. 2 represent mean values (± SD) from independent experiments performed three times each.

[Equation 1]

Cohesive Efficiency (%) = (1 / A-1 / B) × 100

(A is the absorbance after aggregation occurs, B is the absorbance before aggregation occurs)

As shown in FIG. 2, the coagulation activity of wild-type in the culture medium continued to increase until the log growth phase in which algae grew rapidly, specifically 9 days after incubation, and the stationary growth phase. It was confirmed that after 9 days corresponding to the growth phase, that is, at 12 days. On the other hand, in the case of the mut41 , not only showed better cohesive activity than the wild type, it was confirmed to increase continuously.

In particular, the difference in the aggregation activity between wild type and mut41 was the highest on the third day when algal cells rapidly increased, and the aggregation activity of mut41 was about 15% higher than that of wild type.

Mut41, which is a mutation of the astrophylatensis NIES 39 having excellent coagulation activity, is finally an astrophylatensis E41K variant ( Arthrospira). platensis E41K mutant) and was deposited on December 16, 2011 at the biological resource center located in Yuseong-gu, Daejeon, Korea, and was given the deposit number KCTC 12105BP on December 28, 2011.

< Example  4> Chlorophyll content Biomass  Content analysis

In order to confirm the growth activity of the Asrospira plattensis E41K variant, which is a significantly improved coagulation activity of the Asrospira plattensis NIES 39, Asrospira plattensis NIES 39 and Asrospira plattensis E41K variant Biomass content and chlorophyll content (Chlorophyll / DCW) of were measured.

More specifically, the cells of each algae cultured for 12 days were harvested, dry cell weight was measured for biomass content measurement, and chlorophyll content was further measured.

The dry cell weight is Vonshak et al . (Biomass 2: 175-185 (1982)). Specifically, the measurement of the dry cell weight is carried out by filtering the culture suspension with a pre-weighed filter (Whatman Co., USA), and then drying the filter at 105 ° for 3 hours and weighing again. It was. In addition, the measurement of the chlorophyll content is determined by measuring the chlorophyll using methanol from each algae cell, as described in Sartory and Grobbelaar (Hydrobiologia 114: 177-187 (1984)), and then spectroscopically at 665 nm and 650 nm. It was performed by the method of measuring with a spectrophotometer.

The measurement results are shown in FIGS. 3A and 3B, respectively.

As shown in FIG. 3A, the dry cell weight (biomass) was found to be increased by about 180% in the Asrospira Platensis E41K variant, which is a variant compared to Asrospira Platensis NIES 39. On the other hand, as shown in Figure 3b, the chlorophyll (chlorophyll) content per dry cell weight was 14.6 mg / g, which was lower than the wild type Asrospira platensis NIES 39.

In general, when the shade is formed by aggregation of cells, it is known that the growth of cells is inhibited when there is no low light compliance effect because the cells are prevented from being exposed to light in the culture medium. However, from the above results, it was confirmed that the Asrospira plattensis E41K variant can grow cells with excellent efficiency even at low light dose, and thus, low light, which is a big constraint unlike other existing algae even when microalgae mass culture is performed. It was expected that high biomass concentrations could be reached without the acclimation effect.

< Example  5> for coagulation activity pH Influence of

In order to confirm the coagulation activity according to the pH of the novel strain, Asrospyra plathesis E41K variant, the coagulation activity according to the pH of Asrospyra platensis NIES 39 and Asrospyra plathesis E41K variant was confirmed. .

Specifically, each of the 50 ml conical tubes each 10 ml of the culture medium adjusted to pH 4, pH 7, pH 9 and pH 12 using 0.1 M HCl or 6 N NaOH, each of the above The algae cells were inoculated in the pH-regulated medium and cultured for 2 days, and then the aggregation activity was measured in the same manner as in Example 3. The measurement results are shown in FIG. 4.

As shown in FIG. 4, in the case of Asrospira platensis NIES 39, aggregation was induced by adjusting the pH of the medium to an extreme pH value such as pH 4 or pH 12. However, since the pH conditions are not suitable for large-scale algae culture, in order to agglomerate Asrospira platensis NIES 39 by adjusting the pH value, the need for additional work to adjust the pH value of the culture medium after the culture and The problem arises that additional processes are required for treating acid or basic controlled cultures.

On the other hand, the novel strain Asrospyra plathesis E41K variant had a pH of 9 (Ogbonda et. al ., Biores Technol 98: 2207-2211 (2007)) also showed excellent coagulation activity, specifically, about 16% increase in coagulation activity compared to Asrospyra plathesis NIES 39. Therefore, the Asrospyra plathesis E41K variant has a great advantage in obtaining algae by mass production in that it can be obtained by agglutination of cultured algae without additional measures such as adjusting the pH of the culture solution. Confirmed.

< Example  6> Effect of chemical flocculant on flocculation activity

Aggregation of the bird may be derived chemically using different amounts of ionic polymers such as Al ^{+ 3} or Fe ^{+ 3.} Specifically, the surface of the microalgal cells has a negative charge, the negative charge of the cell surface serves to prevent the aggregation of the cells. Therefore, it has been reported that when cations are added to lower or neutralize the charge on the cell surface, aggregation of algae can be induced.

In this regard, chemical flocculants were added to confirm the change of the flocculation effect by the addition of a chemical flocculant, that is, a cation.

More specifically, ferric chloride (FeCl ₃ ), aluminum sulfate (Aluminum sulfate, Al ₂ (SO ₄ ) ₃ ) and zinc sulfate (zinc sulfate, ZnSO ₄ ) in each concentration, specifically 50 mg / l, 100 mg / l, 200 mg / l, 300 mg / l, 400 mg / l and 500 mg / l each were added and coagulation activity was measured in the same manner as in Example 3. 5 shows the results of measuring the effect of the chemical flocculant on the flocculation activity of each algae.

As shown in FIG. 5A to FIG. 5C, in the case of Asrospira platensis NIES 39, coagulation activity was increased by addition of a chemical coagulant, and coagulation activity also increased with the increase of the coagulant addition amount. Specifically, when FeCl ₃ was added at a concentration of 500 mg / l, the aggregation activity was increased by about 17%, and when Al ₃ (SO ₄ ) ₂ was added at a concentration of 500 mg / l, the aggregation activity was increased by about 28%. In the case of ZnSO ₄ , the coagulation activity increased by about 28% when added at a concentration of 200 mg / l.

However, in the case of the new strain Asrospyra plathesis E41K variant, it was confirmed that the increase of coagulation activity was limited by addition of chemical flocculant, unlike Asrospyra plathesis NIES 39 or general algae. The Asrospira Platensis E41K variant exhibits high flocculation activity regardless of the addition of a flocculant, thereby providing excellent algae production without the necessity of additional work and the use of chemical flocculant, which is problematic for environmental pollution and raw material, that is, algae contamination. It was confirmed that it can be obtained.

Korea Biotechnology Research Institute KCTC12105BP 20111228

Claims (7)

Arthrospira platensis E41K mutant (KCTC 12105BP) with enhanced aggregation activity. The method of claim 1, wherein the Asrospira plattensis E41K variant is selected from the group consisting of Asrospira plattensis NIES 39 ( Arthrospira). platensis Asrospira Platensis E41K variant ( Arthrospira ), a variant of NIES 39, KCTC AG30033) platensis E41K mutant, KCTC 12105BP). The method of claim 2, wherein the Asrospyra plathesis E41K variant is selected from the group Asthrophila Platensis NIES 39 ( Arthrospira). platensis NIES 39, KCTC AG30033) asrospira platensis E41K variant ( Arthrospira) characterized in that the variant obtained by treatment of ethyl methane sulfonate (EMS) platensis E41K mutant, KCTC 12105BP). A method for producing microalgae using the Asthrospira platensis E41K mutant (KCTC 12105BP) with enhanced aggregation activity. 5. The method of claim 4,
The method of producing the microalgae is a method of producing a microalgae comprising the step of culturing the agglomeration activity improved Asrospyra platensis E41K mutant (KCTC 12105BP). The method of claim 5,
The microalgae production method comprises the steps of culturing the Athrospira platensis E41K mutant (KCTC 12105BP) with enhanced coagulation activity in a culture medium, and asrospyra platen with enhanced coagulation activity from the culture medium. A method of producing a microalgae comprising the step of obtaining cis E41K variant ( Arthrospira platensis E41K mutant, KCTC 12105BP). The method according to claim 6,
The culturing step is a method for producing microalgae which is performed by culturing the agglomeration activity improved Asrospyra platensis E41K mutant (KCTC 12105BP) in a condition of pH 8 to pH 10. .

Images