• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.6
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• pp.514-519
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• 2012

Abalone culture is one of important coastal fisheries off Wando in the southeast coast of Korea. Since cage culture for abalones was popularized, Understanding of temperature variation, which is important to raise abalones and to prevent their mass mortalities, is necessary. We analyzed temperature data from 2005 to 2009 obtained at Sinji-do and Cheongsan-do off Wando. Sinji-do, which is relatively close to land, had yearly wide range of temperature and rate of temperature variation. It is likely to be caused by heating of solar radiation in summer and cooling in winter at the shallow area. Rate of temperature variation in autumn was higher than that in spring. In summer short term variation of temperature corresponding tidal period was distinguished clearly. Diurnal temperature range, abrupt temperature change, was larger open sea. Comparison between temperatures of two stations and favorable raising conditions of abalones showed that Cheongsan-do, located out to sea, appears to be more appropriate than Sinji-do.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.216-221
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• 2004

Treatment effect of benzyladenopurine (BA) used to block the lateral roots formed on soybean sprouts should be influenced by its applying methods. This study was done to check the effects of temperature and period from seed imbibition into 2 ppm BA solution to the first watering for sprout culture on growth and morphology of soybean sprouts. Imbibed three cultivar (cv. Pungsannamulkong, Sowonkong and Junjery) seeds for 5 houys into 2 ppm BA solution were placed under different temperatures (AT; 20, 30, $40^{\circ}$) and periods (AP; 0, 1, 2, 3, 4 hours). On the 6th day, the soybean sprouts were classified by 4 categories on the base of hypocotyl length; ＞7cm, 4 to 7cm), ＜ 4cm and non-germination to calculate their composition rates, number of lateral roots, lengths of hypocotyl and root diameters at middle and hook of hypocotyl, and fraction dry weights were measured. Germination and growth responses of the cultivars were changed by AT and AP treatments. The responses, lateral root formation and fresh weights were, however, mainly affected by the cultivars used rather than Af treatment. Rate of the sprouts which formed lateral roots was decreased with increased periods to 4 hours, but their number per sprout was not different between the treatments of longer than 3 hours. Lengths of hypocotyl and root organ and total fresh weights were the highest in an hour AP treatment although longer than 3 hour AP treatments did not showed the significant difference in the lengths. Conclusionally AP treatment was more important than Af one in seed aeration for soybean sprout culture immediately after imbibition into BA solution, and was done at least for 3 hours.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.407-418
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• 2015

This study is focused on establishing the optimal conditions to enhance the production of antilisterial substances by Lactobacillus paracasei BK57 isolated from Baikkimchi. In addition, the growth and in situ lactic acid and bacteriocin production of this strain were investigated during the manufacture of fresh cheese. And then the efficacy of using Lactobacillus starter as a protective culture to improve the safety of fresh cheese against Listeria monocytogenes KCTC 3569 was estimated. Maximum growth rate and activity of antibacterial substances were obtained in Lactobacilli MRS broth at $37^{\circ}C$ with controlled pH 6.0 after 30 h of incubation under aerobic condition. However, the growth rate and antimicrobial activity of bacteriocin produced in whole milk supplemented with yeast extract (2.0%) as a substrate were lower than those obtained in MRS broth. Live cells and cell-free culture supernatant of BK57 strain were effective in the suppression of L. monocytogenes in milk, whereas the inhibitory of the bacteriocin obtained from BK57 strain was higher in BHI broth than in milk. During storage at $4^{\circ}C$ and $15^{\circ}C$ for 6 days, no significant difference was found in the cell viability and antimicrobial activity of BK 57 strain in fresh cheese. In samples held at two temperatures, there was at least a 15% reduction in the numbers of the pathogen in fresh cheese artificially contaminated with approximately $10^5CFU/ml$ of L. monocytogenes within 6 days. Our results demonstrated the usefulness of L. paracasei BK57 having antilisterial activity as a biopreservative in the cheese making process.

• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.131-137
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• 1998

The cellulase components were partially purified from the culture filtrate of the alkalophilic bacterium Pseudomonas sp. AC-711 and its enzymatic properties were characterized. The specific activity of the purified major enzyme component was 3.5 units/mg protein as carboxymethyl cellulase and the yield was 23% of the total activity of the culture broth. The molecular weight of the component was 46,000 and the Km and Vmax on CMC were determined as $15.4mg\;mL^{-1}$ and $4.17{\mu}moles\;mL^{-1}\;min^{-1}$, respectively. The enzyme was stable at the temperatures below $60^{\circ}C$ and at the pH range of 4.0~11.0, and the optimal temperature and pH were $60^{\circ}C$ and pH 8.0, respectively. The enzyme activity was not significantly affected by the common surfactants (concentration: 0.05%) such as ${\alpha}$-olefin sulfonate, linear alkylbenzene sulfonate, sodium dodecyl sulfonate, hexadecyltrimethylammonium bromide and Tween 80. The enzyme was activated by the metal ions such as $Ca^{2+}$, $Cu^{2+}$, $Co^{2+}$, whereas inhibited by $Hg^{2+}$ and $Zn^{2+}$. The enzyme exhibited relatively high activity toward amorphous CMC as compared with crystalline substrates such as filter paper and avicel.

• Journal of Aquaculture
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• v.21 no.2
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• pp.70-75
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• 2008

We investigated the optimum salinity and temperature conditions for mass culture of ultra-small rotifer Synchaeta kitina. In the salinity experiment of ranging within 5 and 30 psu, the population growth of S. kitina increased continuously up to 20 psu, and then decreased over 20 psu. Their maximum density showed 390.1 inds./mL at 5 psu. A pre-reproductive phase was shortened in low salinity than high salinity. Also, the maximum offsprings and maximum lifespan and lifespan of the female were 13.4 inds. and 5.9 days, respctively at 5 psu. In the temperature experiments of ranging within 16 and $32^{\circ}C$, the population growth of S. kitina increased continuously up to $24^{\circ}C$, and then decreased over $24^{\circ}C$. The highest maximum density showed 492.8 inds./mL at $16^{\circ}C$. Their offsprings increased significantly with temperature decrease, and the maximum number of offsprings per female was 9.2 females. at $16^{\circ}C$. Their lifespan increased with temperatures decrease and the longest lifespan was to 5.5 days at $16^{\circ}C$. From these results, we conclude that the optimum culture conditions of S. kitina is 5 psu and $16^{\circ}C$.

• Journal of Aquaculture
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• v.11 no.4
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• pp.565-572
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• 1998

Survival rate of larval red spotted grouper, Epinephelus akaara is very low, because mouth size of the larvae is too small to eat normal sizes of rotifers. In order to enhance larval survival, optimal culture conditions for larvae using different live foods and water temperatures were studied. Bigger live food produced larger size of rotifer, when the rotifer was cultured with three different live foods such as Tetraselmis tetrathele, marine Chlorella and Nannochloris oculata. Also, the size of rotifer produced was temperature-dependent showing that higher water temperature induced smaller rotifer. Survial rate of the larvae increased with the increase of water temperature up to $29{\circ}C$. Also, higher larval survials were found at the food density of 15 to 20 individuals per milliliter. The larvae fed L-type or small individuals of L-type rotifer died all within a week, although the larvae fed S-type or small individuals of S-type one survived successfully during this period. The size of small individuals of S-type rotifer collected through fine net became larger in a few hours within larval culture tank. Survival rate of grouper larvae with initial stocking density of 40 thousands in 6-ton concrete tank was 6.3% in 10 days and 0.2% in 53 days after hatching, respectively. Total length of the larvae reached around 29.5 mm in 53days after hatching.

• The Korean Journal of Mycology
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• v.42 no.4
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• pp.312-321
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• 2014

Tricholoma bakamatsutake is one of the edible ectomycorrhizal mushrooms as an allied species of Tricholoma matsutake. This is the first report on physical characteristics of T. bakamatsutake strains collected from Quercus mongolica forests in Korea. The pure cultures of these strains were isolated from the tissues of fruit bodies and the culture characteristics were investigated under different conditions (media, temperatures, nitrogen sources). Most strains showed the highest mycelial growth on potato dextrose agar (PDA) at 20 or $25^{\circ}C$. Two strains of T. bakamatsutake preferred the ammonium-form rather than the nitrate-form as an inorganic nitrogen source. T. bakamatsutake showed significantly slower mycelial growth when compared with T. matsutake from a Korean forest, although the optimum culture conditions for the two allied species were similar. We also tested the ability to form mycorrhizae as well as cellulase activity of T. bakamatsutake. All strains showed cellulase activity on a carboxymethylcellulose (CMC) agar plate. The mycorrhizae on axenic Pinus densiflora seedlings were formed by two strains of T. bakamatsutake after 3 or 8 months of inoculation. P. densiflora seedlings inoculated with T. bakamatsutake had a much higher biomass than un-inoculated seedlings.

• Current Research on Agriculture and Life Sciences
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• v.26
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• pp.71-79
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• 2008

It is known that the content of asparagine, an excellent detoxifying substance of alcohols in human body, is the highest in the roots of soy-sprout. At the same time, it is inferred that soy-sprouts producing more roots are better for detoxifying. In this experiment, the effects of room temperatures on number of watering per day, and duration of soy-sprout culture were carefully investigated. Some of the results obtained are as follows; 1. The yield rate of soy-sprouts for Agakong and Pungsannamulkong was continuously increased up to 9 days. It was higher in room temperature of $30^{\circ}C$ than in $20^{\circ}C$ and was the highest at 8th day of culture with 5 times of watering per day. 2. The asparagine content in soy-sprouts of Agakong and Pungsannamulkong was the highest in cotyledon and the lowest in roots. This rate was higher in the room temperature of $20^{\circ}C$ than in $30^{\circ}C$. 3. The highest asparagine content of soy-sprout of Agakong was 18.9%, obtained in the room temperature of $30^{\circ}C$, cultivated for 8 days with 5 times of watering per day. 4. The highest asparagine content of Pungsannamulkong was 18.8%, obtained in hypocotyl cultivated in the room temperature of $30^{\circ}C$ for 8 days with the number of 2 times watering per day. 5. When an cultivation apparatus of 5 liters volume was used, the optimum seed amount for the highest yield rate was 300g for Agakong and 500g for Pungsannamulkong. At the same time, the number of lateral roots showed increasing tendency with more amounts of soybean seeds used.

• Journal of Microbiology and Biotechnology
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• v.29 no.10
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• pp.1495-1505
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• 2019

The Burkholderia cepacia complex (BCC) is capable of remaining viable in low-nutrient environments and harsh conditions, posing a contamination risk in non-sterile pharmaceutical products as well as a challenge for detection. To develop optimal recovery methods to detect BCC, three oligotrophic media were evaluated and compared with nutrient media for the recovery of BCC from autoclaved distilled water or antiseptic solutions. Serial dilutions ($10^{-1}$ to $10^{-12}CFU/ml$) of 20 BCC strains were inoculated into autoclaved distilled water and stored at $6^{\circ}C$, $23^{\circ}C$ and $42^{\circ}C$ for 42 days. Six suspensions of Burkholderia cenocepacia were used to inoculate aqueous solutions containing $5{\mu}g/ml$ and $50{\mu}g/ml$ chlorhexidine gluconate (CHX) and $10{\mu}g/ml$ benzalkonium chloride (BZK), and stored at $23^{\circ}C$ for a further 199 days. Nutrient media such as Tryptic Soy Agar (TSA) or Tryptic Soy Broth (TSB), oligotrophic media (1/10 strength TSA or TSB, Reasoner's $2^{nd}$ Agar [R2A] or Reasoner's $2^{nd}$ Broth [R2AB], and 1/3 strength R2A or R2AB) were compared by inoculating these media with BCC from autoclaved distilled water and from antiseptic samples. The recovery of BCC in water or antiseptics was higher in culture broth than on solid media. Oligotrophic medium showed a higher recovery efficiency than TSA or TSB for the detection of 20 BCC samples. Results from multiple comparisons allowed us to directly identify significant differences between TSA or TSB and oligotrophic media. An oligotrophic medium pre-enrichment resuscitation step is offered for the United States Pharmacopeia (USP) proposed compendial test method for BCC detection.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.165-192
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• 2022

The microbial metagenome characteristics of bioaerosols and particulate matter (PM) in the outdoor atmospheric environment and the effects of climate and environmental factors on the metagenome were analyzed. The concentrations of bacteria and fungi in bioaerosols and PM were determined by sampling different regions with different environmental properties. A variety of culture-independent methods were used to analyze the microbial metagenome in aerosols and PM samples. In addition, the effects of meteorological and environmental factors on the diversity and metagenomes of bacteria and fungi were investigated. The survival, growth, and dispersal of the microorganisms in the atmosphere were markedly affected by local weather conditions and the air pollutant concentration. The concentration of airborne microorganisms increased as the temperature increased, but their concentration decreased in summer, due to the effects of high temperatures and strong ultraviolet rays. Humidity and microbial concentration were positively correlated, but when the humidity was too high, the dispersion of airborne microorganisms was inhibited. These comprehensive data on the microbial metagenome in bioaerosols and PM may be used to understand the roles and functions of microorganisms in the atmosphere, and to develop strategies and abatement techniques to address the environmental and public health problems caused by these microorganisms.