BACKGROUND ART After 1980's, harmful and poisonous red tides are occurring, centering around the eutrophicated areas of the southern coast of Korea, and the red tides occurring by some microalga species are causing great damage to the aquaculture industry every year. Particularly, Cochlodinium polykrikoides that occurs after August every year is causing great damages to the coastal aquaculture industry in Korea (Park et al., J. Korean Fish. Soc. , 31: 767-73,1998). For this reason, studies on the death and growth inhibition of red tide-causing microalga species are being conducted (Yoshinaga et al., Japan Fish Sci. , 61: 780-6,1995).

In a marine ecosystem, microbial populations play an important role in the occurrence and termination of red tides (Furuka et al., Marine Pollution Bull., 23: 189-93,1992). The number of algicidal bacteria reach the highest level at the termination stage of red tides depending on host organisms in a sea area where the red tides occurred (Yoshinaga et al., Japan Fish Sci. , 61: 780-6,1995).

Bacteria known to have algicidal activity include Alteromonas, Cytophaga, Flavobaterium, Pseudoalteromonas, Saporospira, and Vibrio, and it is reported that such bacteria are directly or indirectly involved in the dissipation of red tides (Lovejoy et al., Appl. Environ. Microbiol. , 64: 2806-13,1993). The algicidal bacteria can kill or lyse a variety of algae, and each of such bacteria has species- specific algicidal activities. For example, algicidal bacterium Cytophaga sp. has various algicidal abilities against Bacillariophyceae, Raphydophyceae and Dinophyceae (Imai etal., Mar. Biol. , 116: 527-32,1993).

However, studies on the algicidal mechanism of the algicidal bacteria are yet incomplete, and it is reported that a rapid reduction of red tide organisms is attributed to the lysis of the organism cells (Imai et al., Mar. Biol. , 116: 527-32, 1993), the death of the organisms by their growth inhibition (Imai et al., Fisheries Science, 61: 628-36,1995) and the death by the inhibition of their mating process from asexual reproduction to sexual reproduction as in Alexandrium catanella (Sawayama et al., Nippon Suisan Gakkaishi, 59: 291-4,1993).

The algicidal mechanisms of the algicidal bacteria can be divided into the following two categories: (1) a mechanism by contact that the algicidal bacteria adhere to the surface of red tide organisms to lyse the red tide organisms (Imai et al., Mar. Biol. , 116: 527-32,1993), and (2) a mechanism that the algicidal bacteria secrete algicidal substances extracellularly to induce the growth inhibition or lysis of the red tide organisms. Most of the algicidal bacteria are included in the second mechanism, and there are reported algicidal mechanisms caused by antibiotics (Kawano et al., J. Mar. Biotechnol. , 5: 225-9,1997), low-molecular weight oligopeptides (Sawayama et al., Nippon Suisan Gakkaishi, 59: 291-4, 1993), proteins (Baker and Herson, Appl. Environ. Microbiol. , 35: 791-6,1978) and heat-unstable extracellular substances (Mitsutani et al., Nippon Suisan Gakkaishi, 58: 2159-69,1992). This reduction of microalgae appears within several hours to several days after inoculation with most of the algicidal bacteria.

This difference in the reaction time has a direct connection with the activity of the algicidal substance, and this reaction time varies depending on the difference of

the production of the algicidal substance and the kind of the inducers.

Thus, studies to reduce red tide damage to the aquaculture industry by inhibiting the growth of red tide-causing microalga using algicidal substances produced by these algicidal microorganisms are being actively conducted.

Particularly, Cochlodinium polykrikoides that caused a first red tide in the year 1982 has caused continuous red tides from the year 1990. After the year 1995, they occurred at a high density of 10,000 cells/m on a massive scale from the southern coast to southeast coast of Korea, thereby causing serious damage to the marine industry. For this reason, studies on red tide prevention to minimize red tide damage are being conducted. However, an attempt to use a pigment as an algicidal substance was not reported.

Pigments are divided into natural pigments and synthetic pigments, and used in various applications, including foods, cosmetics, drugs, and feedstuff additives.

In the case of producing the natural pigments from microorganisms, such natural pigments can be produced at large amounts by fermentation and have stable quality, compared to the case of producing pigments from animals and plants.

The pigments produced from microorganisms have colors that vary depending on cultivation methods and mediums, and also they have the color tones that vary depending on medium composition, culture temperature and pH, etc, even in the same strain (Carels et al., Can. J. Microbiol. , 23: 1360-72,1977). Particularly, it is known that the pigment, which is secondary metabolites, are produced by a typical regulatory mechanism shown in the fermentation of secondary metabolites, such as antibiotics and toxins, and their production is greatly influenced by carbon sources, nitrogen sources, phosphoric acids and trace elements (Wong etal., Myclogia, 73: 649-54,1981).

Hahella chejuensis 96CJ10356 strain (KCTC 2396 = IMSNU 11157) which is a marine microorganism isolated from a marine sediment collected from the coast of Cheju Island, Korea, is a gram-negative motile bacillus. It produces large amounts of exopolysaccharides and red pigments (Lee et al., Systematic and Evolutionary Microbiology, 51: 661-6,2001).

However, the algicidal effect of a pigment derived from genus Hahella microorganisms, including Hahella chejuensis 96CJ10356 strain, is not yet known.

DISCLOSURE OF INVENTION The present inventors have conducted extensive studies to discover a new microorganism having an excellent algicidal effect, and consequently, found that a red pigment (RP10356) produced from Hahella chejuensis 96CJ10356 strain as described above shows an excellent algicidal effect, thereby perfecting the present invention.

Therefore, a main object of the present invention is to provide a method for producing a red pigment having an algicidal effect, the method being characterized by the cultivation of genus Hahella microorganisms.

Another object of the present invention is to provide a red pigment (RP10356) having an algicidal effect, as well as an algicidal formulation containing this red pigment as an active ingredient.

To achieve the above objects, in one aspect, the present invention provides a method for producing a pigment substance having an algicidal effect, comprising the steps of culturing a genus Hahella microorganism; and isolating and purifying a pigment substance showing an algicidal effect from the culture broth using an organic solvent.

In this inventive method, the genus Hahella microorganism is preferably Hahella chejuensis, and more preferably Hahella chejuensis 96CJ10356 strain (KCTC 2396).

In another aspect, the present invention provides a red pigment showing an algicidal effect, which is produced by the above method, and shows an Rf value of 0.98 on silica gel TLC (petroleum ether: acetone: methanol = 5: 3: 2), and the

maximum absorbance at about 539nm. Furthermore, the present invention provides an algicidal formulation containing the red pigment as an active ingredient.

In the present invention, the red pigment shows an algicidal effect against Cochlodinium polykrikoides, Gyrodinium impudicum, or Heterosigma akashiwo.

In still another aspect, the present invention provides a method for removing red tide organisms, the method being characterized by the use of the red pigment, the culture broth of the genus Hahella microorganism, or an organic solvent extract of the culture broth.

In the present invention, the culture broth of Hahella chejuensis 96CJ10356 strain is subjected to extraction with an organic solvent to isolate a pure red pigment (RP10356). To produce the red pigment RP10356 having an algicidal effect from Hahella chejuensis 96CJ10356 strain, this microorganism must be cultured in a suitable medium containing nutrient salts, a trace amount of inorganic salts, and aged seawater.

The nutrient medium which can be used in the present invention include 5% glucose as a carbon source, 0.5% peptone as a nitrogen source, and 0.083g/L KH2PO4, 0.067g/L K2HPO4, 5g/L MgSO4, and lg/L CaCl2. A trace amount of the inorganic salts preferably include 0. 005g/L FeCl26H20, O. OOlg/L MnCl24H20, O. OOlg/L Na2Mo04, O. OOlg/L ZnCl2 and the like.

The crude pigment extracted from the culture broth of the microorganism, and the red pigment RP10356 purified from the crude pigment, were examined for their algicidal effects against Cochlodinium polykrikoides, Gyrodinium impudicum, Heterosigma akashiwo, Alexandrium catenella, and Procentrum micans, which are red tide-causing microalga species. The examination results showed that the crude pigment and the red pigment RP10356 had excellent algicidal effects against Cochlodinium polykrikoides, Gyrodinium impudicum, and Heterosigma akashiwo. The red pigment RP10356 according to the present invention is a fat-soluble red pigment that shows the maximum absorbance at wavelengths of 486nm and 539nm in ethanol.

BRIEF DESCRIPTION OF DRAWINGS FIG 1 shows a process for the extraction and isolation of a red pigment which is produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396).

FIG 2 shows the algicidal effect of a crude pigment produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396), against Cochlodiniumpolykrikoides.

FIG 3 shows the algicidal effect of a crude pigment produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396), against Gyrodinium impudicum.

FIG 4 shows the algicidal effect of a crude pigment produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396), against Heterosigma akashiwo.

FIG 5 shows the algicidal effect of red pigment RP10356 produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396), against Cochlodinium polykrikoides.

FIG 6 shows the morphological change of test strains by the algicidal activity of a crude pigment produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396). A: Cochlodinium polykrikoides ; B: Gyrodinium impudicum ; C : Heterosigma akashiwo ; D: Alexandrium catenella ; and E: Procentrum micans.

FIG 7 shows pH, cells and RP10356 production according to the cultivation of Hahella chejuensis 96CJ10356 strain (KCTC 2396).

FIG 8 shows the results of thin layer chromatography for a crude pigment produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396), and for pigment RP10356 isolated from the crude pigment (l : 2-propanol extract (crude pigment); and 2: RP10356).

FIG. 9 shows the UV absorbance of RP10356 produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396).

FIG. 10 shows four fractions obtained by silica gel chromatography of the crude pigment produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396) (1 : 2-propanol extract (crude pigment); 2: fraction 1; 3: fraction 2; 4: fraction 3; 5:

fraction 4; and solvent condition: petroleum ether: acetone: methanol = 5: 3: 2).

FIG. 11 shows the results of high performance liquid chromatographic analysis of RP10356 produced from Hahella chejuensis 96CJ 10356 strain (KCTC 2396).

FIG. 12 shows the results of high performance liquid chromatographic analysis of pigment RP10356 produced from Hahella chejuensis 96CJ10356 strain (KCTC 2396), in which the chromatographic analysis is conducted at 300- 550 nm by a DAD detector.

DETAILED DESCRIPTION OF THE INVENTION AND REFERRED EMBODIMENT THEREOF The present invention will hereinafter be described in further detail by examples. It will however be obvious to a person skilled in the art that these examples are given for illustrative purpose only, and the present invention is not limited to or by the examples.

Example 1: Extraction and isolation of10356 A strain used in this example was Hahella chejuensis 96CJ10356 strain (KCTC 2396=IMSNU 11157 which had been isolated from a sediment collected from the coast of Cheju Island, Korea (Lee et al., Systematic and Evolutionary Microbiology, 51: 661-666,2001). This strain was inoculated on an STN solid medium (Table 1 below), cultured at 25°C for 48 hours, and then stored at 4 °C while being subcultured in a fresh medium every two weeks.

[Table 1] Component Concentration Sucrose 20 g/L Tryptone 10 g/L NaCl 10 g/L MgSO4 5 g/L CaCl2 1 g/L KH2PO4 0.083 g/L K2HP04 0. 067 g/L FeCl3 0.005 g/L MnC12 0. 001 g/L Na2Mo040. 001 g/L ZnCl2 0. 001 g/L Distilled water 1, 000 ml pH 7.0

To produce red pigment RP10356 from the 96CJ10356 strain, the strain was inoculated on SZoBell medium (Table 2 below) as a basal medium and then cultured at 25°C and 120rpm for 3 days. Next, red pigment RP10356 was isolated from the culture broth.

[Table 2] Component Concentration Glucose 20/L Peptone 5/L Yeast extract 1 FeP04 0. 01 Aged seawater 750 W Distilled water 250 mut pH 7. 2

From the culture broth of the 96CJ10356 strain, the red pigment was extracted by the method shown in FIG. 1. To remove polysaccharides and isolate a pigment from the culture broth of the 96CJ10356 strain which produces large amounts of exopolysaccharides, two-fold volume of 2-isopropanol was added to 1 liter of the strain culture broth, treated with a sonicator (BRANSON 8210, USA) for one hour, and then left to stand at 4°C for 24 hours to remove polysaccharides from the culture broth. The culture broth from which the polysaccharides had been removed was centrifuged at 12, 000g for 30 minutes and filtered through a GF/F filter (Whatmann, #47 mm, USA) to isolate a crude pigment from which the cells had been removed.

To isolate pigment RP10356 from the 2-isopropanol pigment extract (crude pigment) from which the polysaccharides and cells had been removed, the 2- isopropanol pigment extract was concentrated at 45°C under vacuum to remove 2- isopropanol. Then, to remove aqueous soluble components and large amounts of salts and extract fat-soluble fractions from the remaining aqueous layer, one volume of petroleum ether was added to the aqueous layer and shaken for one hour, and the petroleum ether layer was separated by a separatory funnel. To remove moisture from the separated petroleum ether layer, the petroleum ether layer was dried over anhydrous sodium sulfate and filtered through a filter paper (No 5, Watmann, USA), and then concentrated at 40°C under vacuum to remove petroleum ether (FIG 1).

To isolate a pigment having an algicidal property from the crude pigment extract, silica gel chromatography was performed. For this purpose, the crude pigment extract was added to silica gel 60 (0.040-0. 063 mm; Merk, Germany), and a crude pigment was isolated on a glass column ((D2. 5 x 30 cm) filled with the same resin using a mixture of petroleum ether and acetone (7: 3) as a developing solvent. This yielded four fractions having Rf values of 0.98 (bright yellow), 0.96 (dark red), 0.88 (bright red) and 0.59 (blue), respectively. Among them, the pigment fraction having an Rf value of 0.88 is a main pigment, and this pigment fraction was designated"RP10356"and examined for its algicidal effect.

Example 2: Algicidal effects of10356 Algae used in this example are given in Table 3 below. Such microalgae were provided by the aquaculture department of BuKung University (BKU) and the red tide research team of Korea Ocean Research & Development Institute (KORDI). Other microalgae were isolated directly from sea areas where red tides occurred. fable 3] Classification | Scientificname | Medium | Strain | Provision source Cochlodinium f/2 - BKU polykrikoides Dinophyceae Gyrodinium impudicum f/2 KG03 KORDI Procentrum micans f/2 - KORDI Alexandrium catenella f/2 - KORDI Reaphidophyceae Heterosigma akashiwo f/2 - KORDI

For the cultivation of the microalgae, f/2 medium was used (Table 4). This cultivation was performed at 22. 5°C and a light intensity of 150 pEin/m/s in an algal incubator (Je-il Science, Korea) controlled to a light/dark cycle of 16 hours/8 hours. As algal cultures, logarithmic growth phase cells were used in the measurement of algicidal effects. The growth of the algae was measured with a fluorescence spectrometer (F-2000, Hitachi, Japan), or immobilized to 2% Rugol solution and then counted by an inverted microscope (Axon-1000, Zeiss, Germany).

[Table 4] 1. f/2 medium Component Concentration NaN03 0. 075 g NaH2PO4-H20 0. 005 g Na2SiO3 # 9H2O 0. 030 g f/2 trace metal solution 1 F/2 vitamin solution 1 me Aged seawater 1, 000 ml 2. f/2 trace element solution Component Concentration (gAL) MnCl2'400. 18 ZnSO4 # 7H2O 0. 022 CuSO4 # 5H2O 0.01 Na2MoO4 # 2H2O 0. 007 CoCl2-60001 FeCl2 # 6H2O 3. 15 Na-EDTA-2H204. 35 3. f/2 vitamin solution Component Concentration Vitamin B12 1 µg Biotin 1 llg Thiamine-HCl 200 mg Distilled water 1, 000 mQ

(1) Algicidal effects of crude pigment The crude pigment and RP10356, which have been isolated in Example 1, were added to 1 x 103 cells/ml of the culture broth of red tide-causing microalgae (Cochlodinium polykrikoides, Gyrodinium impudicum, Heterosigma akashiwo, jllexandrium catenella, and Procentrum micans) at concentrations 0,0. 1,1. 0,10, 50 and 100, ug/mQ. After 30 minutes, one hour, two hours and 24 hours, each of the treated microalgae was immobilized to 2% Rugol solution, and the number of unlysed cells was counted with an inverted microscope (Zeiss, AxonlO0, Germany), and then the number of lysed cells in the initial inoculated cells was counted. Algicidal effect was calculated according to the following equation: Algicidal effect (%) = [ (number of initial cells-number of survived cells)/ (number of initial cells) ] x 100 The algicidal effect of the crude pigment dissolved in ethanol was examined, and the results showed that when the crude pigment was added to Cochlodinium polykrikoides at a concentration of 0. 1µl/ml, its algicidal effect after 30 minutes and 24 hours were 3.8% and 72.1%, respectively. When it was added at a concentration of 1. 0µl/ml, its algicidal effect after 30 minutes and 24 hours were 63.8% and 98. 7%, respectively. When it was added at the highest concentration of 100µl/ml, its algicidal effect after 30 minutes was 91.3%. As a result, it was shown that the crude pigment had an algicidal effect against Cochlodinium polykrikoides that cause the greatest red tide damage, at a concentration of more than 0. 1µl/ml, and particularly, the crude pigment had excellent initial algicidal

activity at low concentration (FIG. 2).

When the crude pigment was added to Gyrodinium impudicum at a concentration of 0. 1 gQ/mQ, its algicidal effect after 30 minutes and 24 hours were 1.4% and 40.8%, respectively. At a treatment concentration of 1. 0µl/ml, its algicidal effect after 30 minutes and 24 hours were 28.7% and 93.0%, respectively. At the highest treatment concentration of 1000/mg, its algicidal effect after 30 minutes was 60.6%, indicating that it has somewhat lower algicidal activity effect than that against Cochlodinium polykrikoides (FIG 3).

When the crude pigment was added to Heterosigma akashiwo at a concentration of 0. 1 « Q/mQ, its algicidal effect after 30 minutes and 24 hours were 6.5% and 78.8%, respectively. At a treatment concentration of 1. 0, zQ/mQ, its algicidal effect was 23. 8% and 96.3%, respectively. When it was added at the highest concentration of 100µl/ml, its algicidal effect after 30 minutes was 46.4% (FIG 4).

In addition, it was shown that the crude pigment had insignificant algicidal activities against Alexandrium catenella and Procentrum micans. Thus, the crude pigment extracted from the culture broth of the 96CJ10356 strain showed different algicidal effect against the red tide-causing microalgae, and had a very high algicidal effect against Cochlodinium polykrikoides.

(2) Algicidal effect of RP10356 The four fractions isolated as described above were tested for their algicidal effects against Cochlodinium polykrikoides which cause red tide damage in Korea every year and on which the crude pigment was proven to show the highest algicidal effect in the algicidal experiments. The algicidal effect tests for the four fractions were performed in the same manner as the test for the crude pigment. Their algicidal effects were compared with the algicidal effect of the crude pigment, and the comparison results showed that only RP10356 among the four fractions had algicidal effect. The comparison between algicidal effects based on 30 minutes of treatment showed that the crude pigment had an algicidal

effect of 63.8%, whereas RP10356 had a significantly increased algicidal effect of 83.5% at a concentration of 1, me/L. Particularly, the concentrations of RP10356, which shows an algicidal ability of 50%, were 0. 65µl/L at 30 minutes of treatment, and 0. 17µ/L at 24 hours of treatment (FIG. 5 and Table 5).

[Table 5] Time (hr) 0.5 hr 1 hr 2 hr 24 hr Control-2.37 0.79-0. 40 9.49 Ethanol (10-3%)-4. 76 0.79 2. 38 9.92 0.1 Re/L RP10356 13.39 45.61 43.93 69.46 1. 0 µl/L RP10356 83.46 96.54 99.23 99.62 10 AQIL RP10356 91.36 95.47 95.88 96.71 50 µl/L RP10356 94.91 95.27 95.64 96.00 100 Aß/L RP10356 94.47 94. 47 95. 32 94. 89 (3) Observation of microalgae The morphological change of cells by treatment with the crude pigment and RP10356 was observed with an inverted microscope. The morphological change of cells by treatment with RP10356 was observed on the basis of growth inhibition, swelling of cell, lysis of cell, and edysis of armor.

When the crude pigment derived from the 96CJ10356 strain was added to the microalgae at a concentration of 1. O, ct, /L, the swelling and lysis of cells with the passage of time were observed in Cochlodinium polykrikoides, Gyrodinium impudicum, and Heterosigma akashiwo, against which the crude pigment shows algicidal effects (FIG. 6 A, B, C). However, the edysis of armor was observed partially in Alexandrium catenella, against which the crude pigment has a low algicidal effect (FIG. 6D). Also, Procentrum micans showed a small change in their morphology (FIG. 6E).

Furthermore, when the microalgae were treated with the pigment RP10356, the same morphological change as in FIG. 6A was observed in Cochlodinium polykrikoides, indicating that an algicidal substance is the RP10356 pigment of the crude pigment.

Example 3: Production of RP10356 For the mass production of the algicidal substance RP10356 using Hahella chejuensis 96CJ10356 strain, 5 wt% glucose, 0.1 wt% peptone, 0.42g/L KH2PO4, 0.34g/L K2HPO4, 0. 5g/L MgSO4, 2. 0g/L CaCl2, 0. 001g/L CoCl2.6H2O, 0.001g/L MnCl3, 0. 001g/L ZnS04, 0. 001g/L NaMoO4, 750mQ distilled water and aged seawater were added to be a final volume of 3, 000mu, to which the 96CJ10356 strain was then inoculated. The inoculated substance was cultured in a 5L batch culture system at 25°C at 200 rpm and an aeration rate of 1. 5wm.

With the passage of the culture time, the production of polysaccharides was increased, and 81 hours after the culture, it reached the highest value. The growth of cells was increased until 48 hours of the culture, but 74 hours after the culture, the cell growth was decreased. To measure the concentration of the produced RP10356, lmQ of the culture broth was added to 2m of cold ethanol, and treated with a sonicator for 30 minutes, and then centrifuged at 8, 000g for 15 minutes to remove the cells. The supernatant was measured for its absorbance (A539) using spectrophotometer. The results showed that 209mg/L of RP10356 was ultimately obtained (FIG. 7).

Example 4: Characteristics of10356 (1) TLC (Thin-layer chromatography) analysis To purify RP10356 from the 2-propanol extract of crude pigment, 1 pg of the crude pigment was dissolved in 1ml of ethanol. Then, 5µl of the solution was spotted on a silica 60F254S TLC plate (Merck), and the plate was developed to a height of 10cm with a mixture of petroleum ether-acetone-methanol (5: 3: 2) (FIG.

8). This yielded four fractions having Rf values of 0.98 (bright yellow), 0.96 (dark red), 0. 88 (bright red) and 0. 59 (blue), respectively.

(2) Absorption spectrum analysis by UV absorption spectrometer To examine the absorbance of RP10356, a solution of lag/m PP10356 in

ethanol was measured for its maximum absorbance at a wavelength range of 300-700nm with an absorption spectrometer (UV-VIS2401PC, Shimadzu, Japan) (FIG 9). The measurement results indicated that RP10356 showed the maximum absorbance wavelengths at 486nm and 539nm, and a main peak was 539nm.

(3) Mass purification of pigment by silica gel chromatography For the mass isolation and purification of a pigment from the crude pigment extracted with 2-propanol from the culture broth, the crude pigment was purified by silica gel chromatography (silica gel 60,0. 040-0. 063mm, Merck, Germany) using a mixture of acetone and methanol (9: 1) as an elution solvent (FIG 10). The isolation and purification of the crude pigment by the silica gel chromatography yielded four fractions which were eluted in order of bright yellow, dark red, bright red and blue in the same manner as the result of TLC.

Among the four fractions, RP10356, which is bright red in color was isolated.

(4) HPLC analysis The purified pigment was analyzed with a HP 1050 system (Hewlett Packard, USA). In this analysis, a silica gel column (YMC-Pack SIL, 250 x 4.6mm, Japan) was used, and the analysis was performed using a DAD-UV detector (Hewlett Packard, USA) at wavelengths of 539nm, 486nm and 300-800nm while eluting 1. 0mQ of an acetone-methanol (9: 1) solvent per minute (FIGS. 11 and 12). The results of the HPLC analysis indicated that RP10356 showed a retention time of 3.52 minutes under the above conditions, and a single peak was separated even at a wavelength range of 300-800nm.

INDUSTRIAL APPLICABILITY As described above, the present invention provides Hahella chejuensis-

derived red pigment having an algicidal effect. The red pigment (RP10356) according to the present invention has an excellent algicidal effect against red tide-causing species, such as Cochlodinium polykrikoides, Gyrodinium impudicum, and Heterosigma akashiwo, and thus, is useful as an active ingredient of algicidal formulations for removing red tide organisms.