• Ocean and Polar Research
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• v.36 no.2
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• pp.145-156
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• 2014

Macrobenthic biodiversity in the rocky intertidal areas of the Tae-an region, Republic of Korea, has decreased since the Hebei Spirit oil spill in December 2007. We aimed to investigate ecological roles of Pacific oyster (Crassostrea gigas) because recruitment and growth of oysters are critical to the recovery of damaged rocky shore ecosystem. We surveyed two sites monthly: natural rocky substrate and farming substrate, from July 2012 to January 2013 to identify and compare the changes in macrobenthic fauna. The abundance of young oysters was higher at the natural site. On the other hand, the mean height of oyster on the farming substrate was more than twice as great. The abundance of oyster at the natural site increased until October and then continuously decreased until end of study period. However, the abundance of oyster at the farming site constantly decreased from the beginning of study period. These different growth patterns might be attributable to spatial competition between oyster and a barnacle species (Balanus albicostatus) and environmental factors. At the natural site, physical stress factors including dramatic temperature changes and desiccation a few of the major factors limiting growth during aerial exposure. In addition, motile macrobenthos could be detrimental to oysters because they interrupt filter-feeding activities and hence hamper the growth of oysters. We show the higher recruitment of oysters at the natural site and healthy growth in the farming substrate are due to complicated differences in physical and biological stress factors.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.2
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• pp.138-142
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• 2013

As an early warning system to reduce the damage of aquacultured mollusks due to low salinity water, we investigated the possibility of a biomonitoring system measuring the shell valve movement (SVM) of Pacific oyster (Crassostrea gigas) by using the Hall element sensor. In high salinity water of 27 psu, SVMs of Pacific oyster showed spikes which mean a relatively fast closing condition after opened condition of average 10-15 mm, and then the SVM showed back to opening condition slower than closing speed. In water salinity of 20-27 psu, the SVMs were similar to that of 27 psu. However, below 17 psu, it showed abnormal valve movements such as spending more time for shell closure. In 10 psu, we could not detected SVMs due to closed condition during experiment periods. Thus, if we quickly detect abnormal environmental variations like low salinity using bio-monitoring of SVM, it may be contribute to increased productivity by dramatically reducing damages in aquaculture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.772-778
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• 2016

To develop a value-added product from individually quick-frozen oysters Crassostrea gigas (IQFO), we prepared a retort pouched oyster soup (RPOS) from IQFOs and characterized its processing conditions and quality metrics. We found that the most appropriate manufacturing process for the RPOS consisted of half-thawing and washing raw IQF oysters, blanching, adding them to the retort pouch along with other ingredients (base soup stock, IQF oyster extract, radish, bean sprouts, garlic, and red pepper), sealing, retort sterilization ($120^{\circ}$, F0-value 10 min.), cooling, and packaging inspection. The moisture, crude protein, pH and salinity of the RPOS were 91.0%, 2.8%, 6.20 and 0.9%, respectively. The total amino acid content of the RPOS was 2,163.8 mg/100 g, and the main amino acids were glutamic acid, aspartic acid, leucine, proline, lysine and arginine. The primary inorganic ions were Na, K, S and Zn. In taste compounds, total free amino acid content was 313.4 mg/100 g, and the main free amino acids were glutamic acid, taurine, proline, hydroxyproline, aspartic acid, glycine, alanine, valine, lysine and arginine. This RPOS has good storage stability and organoleptic qualities compared with commercial retort pouched shellfish soup, and is suitable for commercialization as a value-added instant seafood soup.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.134-139
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• 2000

Angelica gigas Nakai (danggui) is a popular herb which has been used as a blood-building decoction for recovery from weakness in the Chinese medicine. Its demand increased in functional foods and pharmaceutical industries. For its hygiene, fumigation has been used, but the use of fumigants are going to be prohibited for food processing. In order to investigate gamma irradiation technique for hygiene of danggui, the immunomodulation activity of danggui after irradiation was examined. The water extract of irradiated danggui showed a strong mitogenic effect on splenocytes in vitro to the same level of lipopolysaccharide (LPS) and phytohemagglutinin (PHA). The effect was not different from that of non-danggui. It was tested whether there was any difference between irradiated and non-irradiated danggui in effects on the secretion of antibodies and graft versus host reaction in vivo. It turned out that intraperitoneal (i.p.) administration of the extract of irradiated danggui for 4 days remarkably increased the number of antibody-secreting cells in mice injected with sheep red blood cells (SRBC). Splenomegaly, due to graft versus host reacton, was also increased after 7 days i.p. administration of the extract of danggui in mice injected with allogeneic splenocytes. In these two in vivo test, the effect were not different from those of non-irradiated danggui. These results indicated that immunomodulation activity of danggui might be preserved after irradiation. In the other experiments (data not shown), the irradiated danggui was stable in active component analysis and safe in genetic toxicity test. In further research, the stability in other physiological activity of irradiated danggui will have to be proved before practical application of irradiation for hygiene.

• Korean Journal of Medicinal Crop Science
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• v.17 no.6
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• pp.458-463
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• 2009

This study was conducted to find out some conditions for optimum cultivation of Angelica gigas Nakai by the investigation of root yield and decursin content from different seeding sizes and accumulative temperature. Accumulative temperature from April to October was $4,309^{\circ}C$ on altitude 100 m, $4,242^{\circ}C$ on 250 m, $3,662^{\circ}C$ on 530 m, $3,435^{\circ}C$ on 730 m, and altitude 530~730 m was less $650{\sim}870^{\circ}C$ than altitude 100 m cultivation areas of A. gigas. Seedling stand rate was increased from 86.4% to more than 90% as accumulative temperature decreases, and was increased in above 7 mm of seedling size, and 10% in non-mulching more than PE film mulching. Yield was increased as accumulative temperature decreases and in PE film mulching as 310.2 kg/10a. Also, Yield was increased in 7~9 mm than seedling diameter 5~7 mm as 313.0 kg/10a. Decursin content of primary roots was increased as altitude rises, ie, as 2.55% on altitude 100 m, 3.33% on 250 m, 5.51% on 530 m, and 6.24% on 730 m. Decursinol angelate content appeared little than decursin content as 1.08% on altitude 100 m, 1.37% on 250 m, 1.99% on 530 m, 2.38% on 730 m, and as altitude was heightened, content was increased.

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.26-33
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• 2021

Angelica is a widely used medicinal and perennial plant. Information on the genetic diversity of Angelica populations is essential for their conservation and germ plasmic utilization. Although Angelica is an important medicinal plant species registered in South Korea, no molecular markers are currently available to distinguish it from other similar species from different countries. This developed single nucleotide polymorphism (SNP) markers derived from nuclear ribosomal DNA internal transcribed spacer regions genomic sequences to identify distinct Korean-specific Angelica species via amplification refractory mutation system (ARMS)-PCR curve analyses. We performed molecular authentication of different kinds of Korean-specific Angelica species such as A. gigas Nakai and A. gigas Jiri using DNA sequences in the ITS intergenic region. The SNP markers developed in this study are useful for rapidly identifying specific Angelica species from different countr.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.284-293
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• 2022

In this study, we aimed to optimize the blending conditions of sunflower oil (A), water (B), and oriental sauce (C) for canned smoked oysters Crassostrea gigas in oriental sauce (SOO). Using response surface methodology (RSM), we found that the optimal independent variables [X₁, A/(B+C); X₂, B/C] based on the salinity (Y₁) amino acid nitrogen content (Y₂), and overall acceptance (Y₃) of high-quality SOO were 48.7% (w/w) for sunflower oil, 25.5% (w/w) for water, and 25.8% (w/w) for oriental sauce. Under optimal conditions, the experimental values of Y₁, Y₂, and Y₃ were 1.68±0.4 g/100 g, 155.4±2.4 mg/100 g, 6.2±0.23 score, respectively, which were not significantly different from the predicted values (P<0.05). The SOO prepared under optimal conditions had a higher overall acceptance than commercial canned smoked oysters. These results suggest that developing canned smoked oysters in oriental sauce can be industrialized, and the product is predicted to be competitive in the global market.

• Journal of Aquaculture
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• v.18 no.3
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• pp.200-206
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• 2005

We previously pointed out that the polluted sediment elutriate manifestly affected the early events of reproductive outputs in the Pacific oysters, Crassostrea gigas. A serial dilution of priority xenobiotic sediment elutriates determined by gas chromatography/mass spectrometry (GC/MS) were exposed to gametes of the oyster with different stress burdens to detail the maternal stress transfer to its reproductive outputs. There was an apparent critical concentration over which survival and morphogenesis were significantly affected with more profound damage in morphogenesis. The critical concentration which drives mortality and abnormal morphogenesis of the larvae corresponded to a dilution between 10 and 20% of our elutriate. The adverse effects of the early lives by the xenobiotic exposure over the critical concentration were magnified by the maternal stress from the exposed benzo(a)pyrene (BaP), one of the priority polyaromatic hydrocarbons (PAHs) during the maturation condition. These results indicate that maternal transfer of the xenobiotic compounds from oysters living in the contaminated location might represent a significant adverse effect to their larval population of wild seeds.

• Journal of Aquaculture
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• v.20 no.4
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• pp.205-211
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• 2007

Stress-inducible proteins may function in part as molecular chaperones, protecting cells from damage due to various stresses and helping to maintain homeostasis. We examined the mRNA expression patterns of a 68-kDa heat shock protein (HSP68) and 78-kDa glucose-regulated protein (GRP78) in relation to physiological changes in Pacific oyster Crassostrea gigas under osmotic stress. Expression of HSP68 and GRP78 mRNA in the gill significantly increased until 48 h in a hypersaline environment (HRE) and 72 h in a hyposaline environment (HOE), and then decreased. Osmolality and the concentrations of $Na^+$, $Cl^-$, and $Ca^{2+}$ in the hemolymph of HRE oysters significantly increased until 72 h (the highest value) and then gradually decreased; in HOE oysters, these values significantly decreased until 72 h (the lowest value), and then increased. These results suggest that osmolality and $Na^+$, $Cl^-$, and $Ca^{2+}$ concentrations were stabilized by HSP68 and GRP78, and indicate that these two stress-induced proteins play an important role in regulating the metabolism and protecting the cells of the Pacific oysters exposed to salinity changes.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.37-42
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• 2012

Objectives : Angelica Gigantis Radix is prescribed as the root of different Angelica species on the pharmacopoeia in Korea, Japan and China. Chemical components and their biological activities were also different according to their species. A study for the development of simple method to compare Angelica roots was needed. In order to classify them, the methods such as DNA sequencing analysis and taste sensor were applied to three Angelica species like Angelica gigas, Angelica acutiloba and Angelica sinensis. Methods : PCR amplification of intergenic transcribed spacer (ITS) region was performed using ITS1 and ITS4 primer from nine Angelica roots, and then nucleotide sequence was determined. Taste pattern of samples were measured using the taste-sensing system SA402B equipped with a sensing unit, which consists of artificial lipid membrane sensor probes of anionic bitterness, astringency, saltiness, umami, and cationic bitterness (C00, AE1, CT0, AAE, and AN0, respectively). Results : As a result of comparing the similarity of the ITS region sequences, A. sinensis was discriminated from the others (A. gigas and A. acutiloba). Equally this genetic result, A. gigas and A. acutiloba showed similar taste pattern as compared to A. sinensis. Sourness, bitterness, aftertaste of bitterness, astringency, and aftertaste of astringency of A. sinensis were significantly high as compared with A. gigas and A. acutiloba. In contrast, richness was significantly low. Conclusions : These taste pattern can be used as a way of comparison of Angelica species and this technic could be applied to establish a taste pattern marker for standardization of herbs in various purposes.