• Journal of Mushroom
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• v.20 no.4
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• pp.193-198
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• 2022

The biological efficiencies of promising Pleurotus spp. were evaluated. Pleurotus ostreatus, Pleurotus tuberregium,and Pleurotus sajor-cajuwere investigated at temperatures of 22℃, 20℃, and 18℃ to determine their ability to adapt to temperatures that are likely to be found in subtropical regions. The experiment was conducted using a substrate comprising Popular sawdust 60% + cotton seed 20% + beet pulp 20% under a relative humidity of 65%. The results indicated that there were significant differences in terms of biological efficiency between the species: P. tuber regium 128.84% at 22℃, P. ostreatus 108.41% at 22℃, and P. sajor-caju is 80% at 20℃. The common temperatures at which all species showed the highest biological efficiencies were 22℃ and 20℃. Therefore, the production of the evaluated species was equal to or surpassed biological efficiencies reported in tropical environments, thereby demonstrating a potential opportunity to adapt to tropical environments without compromising quality standards.

• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.125-132
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• 2003

The levels of heavy metals (total-mercury, cadmium, lead and chromium) in shellfishes, such as oyster (Carassostrea gigas), blue mussel (Mytilus edulis), arkshll (Scapharca broughtonii) and little neck clam (Ruditapes philippinarum), were determined. The samples were collected from 11 stations for oyster and 12 stations for blue mussel in the South Coast of Korea, and little neck clam and arkshell were collected from Koheung and the Kangjin Bay, respectively, during 1999 to 2000. The average concentrations of heavy metal in 4 different species of shellfishes analyzed were ranged from 0.007 to 0.009 ${\mu}g/g$ for total-mercury; 0.232 to 0.559 ${\mu}g/g$ for cadmium; 0.107 to 0.220 ${\mu}g/g$ for lead; and 0.116 to 0.364 ${\mu}g/g$ for chromium on wet basis. The highest level of total-mercury, lead, cadmium, and chromium in the samples analyzed were all below the quarantine limit of the Korean regulation and guideline established by the U.S.Food and Drug Administration for human consumption. The levels of heavy metals in the samples were negligible, which could be endogenous. It was elucidated that oyster was able to accumulate 2-times more cadmium than blu mussel in this study.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.4
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• pp.344-348
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• 2019

This study assessed the microbiological hazards of gloves worn during the shell shucking process of the oyster Crassostrea gigas, and we suggest an in situ method for minimizing microbial contamination. The study consisted of two groups, one in which the working gloves were periodically replaced (PRG) with new gloves, and another in which the gloves were not replaced (NRG). In the PRG group, gloves were replaced every 2 h during 8 h of processing. Food pathogenic bacteria Escherichia coli, Salmonella species, and Listeria monocytogenes were not found in any samples, including gloves and shucked oysters. However, Staphylococcus aureus (SA) was detected in some samples, and the contamination levels were correlated with the working time and the regular replacement of gloves. SA was not detected on gloves or oysters of the PRG group. However, it was detected in the range of <$15CFU/15cm^2$ to $2.9{\times}10^2CFU/15cm^2$ on gloves after 6 h of continuous work, and from <$15CFU/15cm^2$ to $2.23{\times}10^2CFU/15cm^2$ on oysters after 8 h. These results indicate that the SA contamination in shucked oysters originated from the working gloves, and that replacement of working gloves every 2-4 h will minimize SA contamination in oyster products.

• Journal of Mushroom
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• v.2 no.2
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• pp.69-75
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• 2004

This study was carried out to investigate effect of $CaCO_3$ treatment on cultivation of oyster mushroom for suppression of green mold disease and for promotion of mycelial growth to stabilize mushroom production in field and laboratory experiment. Treatment of $CaCO_3$ in PDA media promoted mycelial growth of mushroom and suppressed that of green mold. Addition of $CaCO_3$ in rice straw substrate increased mushroom mycelial growth compared with control. In that case, growth of green mold increased up to treated 0.6% $CaCO_3$ but decreased in treatment beyond 0.8% $CaCO_3$. There were some differences on effect of $CaCO_3$ treatment according to green mold species. Trichoderma longibrachiatum was effected but T. virens was not effected by treated $CaCO_3$. Differences among mushroom strains by treated $CaCO_3$ were not shown. It is confirmed that treatment of $CaCO_3$ can promote mushroom mycelial growth but it's not clear in the field. In the result of field test, treatment of $CaCO_3$ in rice straw substrates tended to increase yield and decrease incidence of disease compared with non-treatment. These results suggest that $CaCO_3$ treatment on cultivation of oyster mushroom can be applied to take preventive steps against of green mold disease.

• Journal of Mushroom
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• v.21 no.3
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• pp.179-184
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• 2023

The development of automated bottle cultivation systems has facilitated the large-scale production of Pleurotus ostreatus, a commonly cultivated oyster mushroom species in South Korea. However, as the consumption of this product is decreasing and production quantities are exceeding demand, farmers are seeking various other mushroom types and cultivars. In response to this, we have developed a new oyster mushroom cultivar named 'Sena'. This high-yielding cultivar has a white pileus and excellent quality. The white oyster mushroom cultivars 'Goni' and 'Miso' were selected as parental strains from the genetic resources of the National Institute of Horticultural and Herbal Science's Mushroom Division. By crossing their monokaryons, hybrids were developed and subjected to cultivation trials and characteristic evaluations to select the superior cultivar. The optimal temperature for 'Sena' mycelial growth is 25-30℃, with inhibition occurring at temperatures above 30℃, whereas the temperature for mushroom growth is 14-18℃. The mushrooms grow in clusters, with the white pileus having a shallow funnel shape. Optimal mycelial growth occurs in malt extract agar medium. When cultivated in 1,100 cc bottles, the 'Sena' cultivar had 35 available individuals, surpassing the number 16 available from the control cultivar 'Goni'. The yield per bottle also increased by approximately 157 g, a 24% increase over the control cultivar amount. When 300 g samples of harvested mushrooms were packed and stored at 4℃ in a cold storage facility for 28 days, the weight loss rate of 'Sena' was approximately 4.22%, lower than that of 'Goni'. Moreover, the changes in pileus and stipe whiteness (measuring 6.99 and 8.33, respectively) were also lower than those of the control cultivar. Since the appearance of a white cap is crucial for quality assessment, the 'Sena' cultivar is superior to the 'Goni' cultivar in terms of both weight and quality after undergoing low-temperature storage.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.4
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• pp.213-228
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• 2009

This study was conducted to investigate spatio-temporal changes in macrobenthic community structure and benthic environmental conditions in Geoje-Hansa Bay, which is the greatest oyster producing site in Korea. Field survey for benthic environment and macrobenthos was seasonally carried out at 15 stations covering oyster farming sites and non-farming sites from February to November, 2008. The grain size of surface sediments was dominated by very fine silt with the mean phi of about $9\;{\Phi}$ and TOC was 1.9% on average. Mean dissolved oxygen content was 8.1 mg/L and lowest in August corresponding to the 2nd degree in seawater quality criteria. Total species number was 351 and mean density was $3,675\;ind./m^2$, both of which were dominated by polychaete worms. Spatio-temporal variation in above two biological variables was great with higher values seasonally in spring and spatially in channels rather than inner bay. Dominant species were Lumbrineris longifolia (21.3%), Aphelochaeta monilaris (17.8%) and Ericthonius pugnax(6.1%), all of which are typical species of organically enriched area. From the multivariate analyses, the whole macrobenthic community was distinguished into two groups of channel and inner bay group. Spatio-temporal changes of macrobenthic community in Geoje-Hansan Bay were related to those of TOC and acid volatile sulfide (AVS). Our results showed that Geoje-Hansan Bay should be intermediately affected by organic pollution, and that such organic enrichment was more remarkable at farming stations in the inner bay.

• Journal of Mushroom
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• v.17 no.4
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• pp.224-229
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• 2019

The two most common mushroom species grown in Korea are pearl oyster mushroom (Pleurotus ostreatus) and king oyster mushroom (P. eryngii). In recent years, the production of king oyster mushroom greatly increased due to the automation of the cultivation facilities, and it became a major export mushroom owing to its excellent shelf life. However, the increase in the production of king oyster mushroom led to a decline in its market price; thus, necessitating the development of new mushroom species that could replace king oyster mushroom, to diversify the mushroom market for the benefit of both, the producers and the consumers. The Mushroom division at the National Institute of Horticultural & Herbal Science (NIHHS) reported the development of a new interspecific hybrid between P. ferulae and P. tuoliensis, referred to as 'Creamy.' Two parental strains KMCC00430 (Bisan2ho, P. ferulae) and KMCC00461 (P. tuoliensis) were selected based on the results of genetic resource analysis, and their monokaryons were collected. About 1,000 Mon-Mon crosses were performed and 73 of them were selected. Following repeated cultivation tests and strain analyses, we selected strain 7773, which had a bright creamy pileus and a thick straight stipe, and named it 'Creamy.' Optimum temperature for mycelial growth of Creamy was 25-30℃, and that for fruiting body growth was 16℃. The pileus, which had a brighter creamy color, was small in size with a diameter of 61.2 mm. Although it was cultivated in suboptimal conditions, such as low temperature and high CO₂ concentration, Creamy was characterized by its straight and smooth stipe. Field production tests and further analyses indicated that the yield of Creamy was 5% higher than that of Baekhwang. It is expected that Creamy, the new interspecific hybrid with a bright creamy pileus and a pleasant flavor, will help create new opportunities for mushroom farmers and diversify the mushroom market.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.281-285
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• 1979

A species of enigmatic amoeba was found front the oysters culcured in Jinhae Bay and the Goje Bay in September-October 1978 and October 1979. Occurrence and the morphological characteristics of the amoeba were studied. Based on their peculiar morphological characters the enigmatic body was a species of parasitic amoeba. The amoebas were morphologically very similar to the amoeboid parasite described by Sawyer(1977). Occurrence of the oysters infected with the amoeboid ranged from zero to $13.3\%$. The infection rate did not show any relations to the depth of water where the oysters were suspended. The longest diameter of the amoeba is $24\;\mu$. The thin outer membrane is lightly stained with eosin and PAS positively. Initially one amoeboid was found in an ovum, and later it propagated to 3 to 4 individuals.

• Animal Systematics, Evolution and Diversity
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• v.16 no.2
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• pp.203-211
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• 2000

Partial mitochondrial 16S rDNA and COI gene were amplified using PCR and sequenced for four species of oysters in Korea. Phylogenetic relationships among them were inferred from their aligned sequences by neighbor-joining method. The sequence comparison data of two mitochondrial genes showed that the genetic distinction between two oyster genera (Crassostreo and Ostrea) was obvious. Phylogenetic analysis based on the nucleotide sequences and A+T percentage of two genes indicates that C. gigas and C. nippona strongly formed a sister group and then C. ariakensis was clustered with the clade although that based on amino acid sequences of COI gene by neighbor-joining method represented different phylogenetic tree.

• Korean Journal of Ichthyology
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• v.35 no.3
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• pp.189-193
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• 2023

Two specimens of Omobranchus fasciolatoceps (33.8~46.7 mm SL) were collected from oyster reefs of Osu-ri, Geoje-myeon, Geoje-si, Gyeongsangnam-do, Korea. This species is characterized by having 32~34 dorsal fin rays, 24~25 anal fin rays, 13 pectoral fin rays, 2 interorbital pores, 8 circumorbital pores, 5~7 lateral line tubes, fleshy crest on head and sexual dimorphism in female that have lost the posterior canines in both jaw. We propose the new Korean name, "Ppul-be-do-ra-chi", for the species.