• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.2
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• pp.129-134
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• 2014

Two neuropeptides were purified from the acidified tube feet extract of the starfish Asterias amurensis by C18 reversed phase and size-exclusion high-performance liquid chromatography (HPLC). The tube feet extract and the purified peptides (AST-I and AST-II) showed potent contractile activity on dorsal retractor muscle (DRM) of the starfish Asterina pectinifera and intestine (smooth muscle) of the panther puffer Takifugu pardalis. Treatment of the purified peptides with dithiothreitol (DTT) for 60 min at $37^{\circ}C$ significantly altered their retention times, suggesting that these compounds contained disulfide bonds. The molecular weights of AST-I and AST-II were determined to be 2064.2 Da and 6137.2 Da, respectively, by MALDI-TOF mass spectrometry.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.158-158
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• 2003

Bioassays using gametes of sea urchins are widely used in ecotoxicological assessments of marine environments. Since most of sea urchin species in Korean coastal water spawn from spring to autumn, bioassay with them during the winter is impossible. In the course of developing standard methods for bioassays with Korean species, we found a winter-spawning starfish, Asterias amurensis, Since reproductive mode of asteroids is similar to echinoids, the bioassay protocol for sea urchins could be applied similarly to the starfish. Here, we tested and determined several conditions for the acceptability of bioassay with A. amurensis. The least required time for formation of fertilization membrane of fertilized eggs to be easily distinguished from unfertilized ones was 60 min. The threshold of sperm to egg ratio that could make acceptable fertilization rates in controls was 3000. The allowed time for manipulation of sperm after dilution in seawater was at most 3 hr. The optimal exposure time of sperms when the response against toxicant solution was relatively stable was in the range of 20-60 min. The tolerance range of sperms to the salinity of test solution was 26-38 psu. The sensitivity of A. amurensis sperm was intermediate among marine organisms commonly used in aquatic toxicity tests. The sperm bioassay with A. amurensis can be satisfactorily applied to toxicity assessments of marine environments.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.57-61
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• 2002

To investigate the characteristics of carbon sources utilization by the intestinal microflora of starfish, starfishes (Asterias amurensis) were collected from the South Sea near Jangheung-gun sumun-ri of Jeollanam-do on July 14,2000. The population densities of heterotrophic bacteria were in the range of $8.65{\pm}0.65{\times}10^3\cfu{\cdot}g^{-1}$ in the interval organs of starfish. Total 24 strains (Gram-negative bacteria. 11 strains, Gram-positive bacteria: 13 strains) from the internal organs of starfish were isolated. Dominant bacteria were Genus nbrio, Staphylococcus, and Corynebacterium. A high percentage of isolates was Gram positive rods. The catalase and oxidase positive were shown 54.2% and 20.8% of isolated bacteria, respectively. Isolated Gram negative and positive bacteria utilized various carbon sources. Among them, glucose could be utilized by all the isolated Gram negative bacteria, and sucrose, mannose, and maltose were utilized by a relatively high percentage of isolates. On the other hands, adipate and phenyl acetate were shown no utilization. In case of Gram positive bacteria, glucose was shown the highest utilization and the next highest utilization was fructose, trehalose, and maltose.

• Fisheries and Aquatic Sciences
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• v.25 no.11
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• pp.572-578
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• 2022

An organism's physiological processes and behaviors are regulated by neuropeptides and hormone peptides. The first neuropeptide identified from echinoderms is SALMFamide. The two most well-studied SALMFamide neuropeptides are S1 and S2, which possess myoactivity on apical muscle, tube feet, and the cardiac stomach of starfishes. However, neuropeptide candidates identified from SALMFamide's precursor protein sequence have not been investigated. This study aims to compare the bioactivity of SALMFamide neuropeptides from the starfish Asterias rubens using various starfish muscle preparations. In this study, the bioactivity of the L-type SALMFamide neuropeptides from the starfish A. rubens, AYHTGLPFamide (SALMFa-A) and the derivative AYHSALMFamide (SALMFa-B) was investigated. The neuropeptides were applied on Asterias amurensis apical muscle, tube feet, which revealed that the neuropeptides exhibit relaxing activity on apical muscle but no activity on tube feet. The native SALMFa-A peptide had lower relaxing activity on the apical muscle compared to the derivative peptide SALMFa-B. The relaxing activity of two neuropeptides also was compared with those on the apical muscle of Patiria pectinifera, which revealed relaxing activity as well as SALMFamide-S1 and S2 neuropeptides. Moreover, the investigation of SALMFa-A and SALMFa-B peptides' bioactivity on P. pectinifera cardiac stomach muscle also showed slight relaxing activity.

• The Korean Journal of Ecology
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• v.26 no.6
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• pp.307-312
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• 2003

To study the diversity of heterotrophic bacteria isolated from intestine of starfish, Asterias amurensis, we collected starfishes from the coastal area near Jangheung-Gun, Jeollanam-Do, Korea during July, 2000. Population density and bacterial diversity in the intestine of starfish were measured. The results were as follows; The population densities of heterotrophic bacteria in the intestine of starfish were 8.65${\pm}$0.65${\times}10^3\;dfu\;g^{-1}$. Gram positive bacteria occupied 59% among 29 isolates. The community structure of dominant heterotrophic bacteria in the intestine of starfish consisted of Bacillaceae in the low G+C gram positive bacteria subphylum, Microbacteriaceae in the high G+C gram positive bacteria subphylum, and Alteromonadaceae in ${\gamma}$-Proteobacteria subphylum. Among eight strains of Bacillus spp., three strains showed more than 97% identity, but five strains showed about 90% identity with type strain on the basis of partial 16S rDNA sequence.

• Journal of Life Science
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• v.24 no.5
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• pp.491-497
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• 2014

Nowadays, starfish is one of problems about interruption of marine ecosystem, so many researchers are focusing on application of the starfish (Asterias amurensis). In this study, we investigated the contractile and relaxant activity of the smooth muscles and the antimicrobial and antioxidant activity of six different tissues (muscle, gut, liver, tube feet, gonads, and body) of A. amurensis. Frozen samples were extracted with distilled water containing 1% acetic acid. Extracts from all the tissues, except the body tissue, showed potent antimicrobial activity against Escherichia coli D31. The dorsal retractor muscles (DRM) of muscle and gut extracts showed strong contraction responses. On the other hand, contractile activity on esophagus of squid Todarodes pacificus could be detected in all tissues tested. The contractile activity of the liver extract was higher than that of the other tissues. The body, tube feet, and liver extracts showed the contractile activity on the intestine of the panther puffer fish (Takifugu pardalis). Relaxation response on the DRM of starfish (A. pectinifera) was observed in all tissues tested. Increased antioxidant activity was observed in the gut, liver, and body extracts. The results suggest that the starfish (A. amurensis) is a potential source of novel bioactive compounds.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.432-438
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• 2015

This study examined the antimicrobial, antioxidant, and tyrosinase inhibitory activities of bioactive compounds extracted from two starfish, Asterina pectinifera and Asterias amurensis, using solvent extraction after $Protamex^{TM}$ hydrolysis. Methanol and acetone fractions collected by stepwise extraction from specimens were subjected to silica gel column chromatography (SGCC) (200 mesh and 400 mesh), followed by high-performance liquid chromatography (HPLC). Two fractions (7:3 and 5:5 chloroform : methanol ratio, v/v) eluted using silica gel column chromatography from the two starfishes showed higher antimicrobial activity against Propionibacterium acnes and dermatophyte fungi (Epidermophyton floccosum, Microsporum audouinii, Trichophyton ferrugineum, Trichophyton mentagrophytes, and Trichophyton rubrum), antioxidant activity ($EDA_{50}$, mg/mL), and tyrosinase inhibitory activity compared to the other fractions. The final fractions obtained from Asterina pectinifera (RT 7.53, 8.93, and 10.48 min) and Asterias amurensis (RT 5.02 min) by SGCC (400 mesh) and HPLC from two SGCC fractions (200 mesh) showed 8.94 and 15.59 mg/mL antioxidant activity ($EDA_{50}$) and 46.89 and 40.19 % tyrosinase inhibitory activity, respectively. Extracts from starfishes are potential cosmetic basic material.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.67-75
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• 2013

Korea has developed coastal farming industry due to the environmental characteristics that its three sides are surrounded by sea. The damage of coastal farming industry caused by Asterias Amurensis with very strong reproductive rate and predaciousness has increased sharply every year. Moreover, Asterias Amurensis preys on living fish and shellfish and so the damage of fishermen is vern greater. In this paper, a method is proposed to extract effectively the features from the image of Asterias Amurensis acquired in the water. Because the proposed method extracts convex features using 6-directional scanning, it selects a fewer number of feature candidates than the conventional one. In addition, after selecting candidate concave points using the extracted convex features and centers of region, the final concave features are extracted. Due to the features of the starfish which lives in groups, individuals of the starfish in the input image are concentrated. Thus, it is significant to minimize the number of feature candidates extracted from the input image. The experimental results indicate an improvement of the proposed feature extraction method over the conventional one as evidenced by the fact that the feature extract was 88 % of the feature candidates.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.83-88
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• 2010

This study is going to suggest the technology to recognize a starfish by judging various starfish images. In case of recognition of single objects of the asterias amurensis, a starfish can be judged by using concave features and short line features but in case of multiple objects, it is impossible to extract the features of a starfish using concave features or short line so that it can't be recognized as a starfish. Accordingly, it is going to suggest the recognition technology using the features such as numbers of standard deviation, relative degree standard deviation and valid deviation of a long line by using the region central moment and a long line of multiple objects. As a result of experiments of the suggested technology, there were cases that recognition failed because the conditions of the standard deviation of a long line or the numbers of valid deviation of the relative degree couldn't satisfy the conditions but around 95% of a high recognition rate was shown.

• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1635-1644
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• 2018

Asterias amurensis (starfish) is a marine organism that is harmful to the fishing industry, but is also a potential source of functional materials. The present study was conducted to analyze the profiles of fatty acids extracted from A. amurensis tissues and their anti-inflammatory effects on RAW264.7 macrophage cells. In different tissues, the component ratios of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids differed; particularly, polyunsaturated fatty acids such as dihomo-gamma-linolenic acid (20:3n-6) and eicosapentaenoic acid (20:5n-3) were considerably different. In lipopolysaccharide-stimulated RAW264.7 cells, fatty acids from A. amurensis skin, gonads, and digestive glands exhibited anti-inflammatory activities by reducing nitric oxide production and inducing nitric oxide synthase gene expression. Asterias amurensis fatty acids effectively suppressed the expression of inflammatory cytokines such as tumor necrosis $factor-{\alpha}$, interleukin-$1{\beta}$, and interleukin-6 in lipopolysaccharide-stimulated cells. Cyclooxygenase-2 and prostaglandin $E_2$, which are critical inflammation biomarkers, were also significantly suppressed. Furthermore, A. amurensis fatty acids reduced the phosphorylation of nuclear $factor-{\kappa}B$ p-65, p38, extracellular signal-related kinase 1/2, and c-Jun N-terminal kinase, indicating that these fatty acids ameliorated inflammation through the nuclear $factor-{\kappa}B$ and mitogen-activated protein kinase pathways. These results provide insight into the anti-inflammatory mechanism of A. amurensis fatty acids on immune cells and suggest that the species is a potential source of anti-inflammatory molecules.