• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.337-343
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• 2020

In this study, the medium optimization for cell growth and metabolite formation of Haematococcus sp. under mixotrophic cultivation was investigated. As a result, modified MS medium was selected as the basal medium; glucose was selected as the carbon source, with an optimum concentration of 10 g/l, and potassium nitrate was chosen as the nitrogen source, with an optimum concentration of 1.9 g/l. Under optimum conditions, Haematococcus sp. demonstrated an increase in biomass concentration from 0.18 gDW/l to 5.58 gDW/l in 14 days, after which there was a 31-fold increase in its growth. At the same time, the concentrations of chlorophyll and carotenoids were 172.16 mg/l and 42.33 mg/l, respectively. This work will contribute to the basic data for mass cultivation of microalgae.

• Journal of Digital Convergence
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• v.16 no.4
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• pp.231-249
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• 2018

The purpose of this study is analyze the factors affecting the standard precaution(SP) performance on the knowledge, awareness, attitude and safety environment for SP of healthcare workers of general hospitals. The research method was a descriptive research study. The subject were 262 of healthcare workers of general hospitals. The data were analyzed using descriptive statistics, t-test, Chi-square test, ANOVA, Person's correlation coefficient and Multiple regression analysis using the SPSS program. As a result of the correlation analysis SP Performance was positively correlated with attitude (r=.18, p=.003), safety environment (r=.42, p<.001) and awareness (r=.63, p<.001). As a result of the stepwise multiple regression analysis on the factors influencing SP performance were SP awareness and safety environment. Therefore, in order to improved performance of SP, it's important to improve a awareness and safety environment of SP. Different and persistent infection management educational programs that consider the occupational characteristics and monitoring are required.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.376-382
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• 1990

An extracellular cellulase producing bacterium YE-5 was isolated from soil, and identified as a Cellulomonas sp. by its taxonomical characteristics. The maximal activities of avicelase (0.35 units/ml), CMCase (3.18 units/ml), FPase (0.315 units/ml) and $\beta$-glucosidase (0.882 units/ml) were obtained when this strain was cultured for 48 hrs at $30^{\circ}C$ in a medium containing 0.8% (w/v) Solka floc, 0.06010 (wlv) urea, 0.1% (w/v) $K_2HP0_4$, 0.1% (w/v) $MgS0_4.7H2_0$, 0.2% (w/v) bacto peptone, 0.2% (w/v) yeast extract and pH 6.5. The cellulase was purified by ammonium sulfate fractionation, DEAE-Sepharose column chromatography and Sephadex 6-100 column chromatography from culture filtrate of Cellulomonus sp. YE-5. The molecular weights of purified avieelase, CMCase I, and CMCase II were estimated to be about 95,000 ~ 105,000, 46,000 ~ 47,000 and 120,000 ~ 125,000, respectively.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.252-257
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• 1994

A new hydrogen sulfide-oxidation bacterium, Thiobacillus sp. was isolated from waste coal mine water around Hawsun in Chunnam province. The isolate was motile gram-negative rod shape, formed spore and grew up to be aerobically facultative chemolithotroph by using energy released from the oxidation of reduced inorganic sulfur compounds. It could assimilate various kinds of organic compounds and grew well upon thiosulfate-supplemented basal medium. To the lelvel of 32 mM in thiosulfate concentration, thiosulfate in itself was utilized as energy source for growth. However, from those of the higher concentration than 32 mM, thiosulfate functioned specifically as the substrate inhibitor rather than as the energy source. It was found that the optimum thiosulfate concentration for growth was 32 mM. The G+C content of the DNA was 65.0 mol%. The isolate had 16 : 1 + 17$_{cyc}$, 16 : 0 as their major non-hydroxylated cellular fatty acids, 3-OH 12 : 0 as a hydroxylated fatty acid and also contained unidentified $C_{18}$ branched fatty acid. The ubiquinone system in the respiratory chain was Q-9. Based on the physiological and biochemical characteristics, the isolate was assigned to a novel species of the genus Thiobacillus sp. iw.

• Journal of Pharmacopuncture
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• v.18 no.2
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• pp.60-66
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• 2015

Objectives: This study was carried out in order to find both the single-dose intramuscular injection toxicity and the approximate lethal dose of samjeong pharmacopuncture (SP) in Sprague-Dawley (SD) rats. Methods: The SD rats in this study were divided into four groups, one control group (1.0 mL/animal, normal saline) and three experimental groups (0.25, 0.5, and 1.0 mL/animal, SP). All groups consisted of five male and five female rats. SP was injected as a single-dose intramuscularly at the thigh. After the injection, general symptoms and weight were observed for 14 days. After the observations had ended, hematologic and serum biochemical examinations, necropsy and a local tolerance test at the injection site were performed. The experiments were carried out at the Good Laboratory Practice firm, Biotoxtech Co. (Cheongwon, Chungbuk). Animal experiments were approved by the Ethics Committee (Approval Number: 130379). Results: No deaths occurred in any of the three experimental groups. The injection of SP had no effects on the general symptoms, body weights, results of the hematologic, and serum biochemical examinations, and necropsy findings. In local tolerance tests at the injection sites, mild inflammation was observed in the experimental group, but it did not appear to be a treatment related effect. Conclusion: Under the conditions of this test, the results from the injection of SP suggest that the approximate lethal dose of SP is above 1.0 mL/animal for both male and female SD rats. Therefore, the clinical use of SP is thought to be safe.

• Research in Plant Disease
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• v.18 no.1
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• pp.57-61
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• 2012

In March 2010, grafted cucumber cultivated in the greenhouse showed a severe rot on crown resulting yellowing and wilting of the leaves. The symptoms of naturally infected plants showed dark brown, watersoaked lesions at the base of the stem. The fungus produced mass of white mycelium and yellow to orange spores in necrotic lesions on dead and dying plants. Fungus was isolated from rotted tissues of the crown and root. On the basis of morphological characteristics, ITS sequence and pathogenicity tests, the isolate was identified as Fusarium solani f. sp. cucurbitae. This is the first report of the crown and foot rot of grafted cucumber caused by F. solani f. sp. cucurbitae in Korea.

• Journal of Life Science
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• v.7 no.2
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• pp.112-118
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• 1997

In previous paper Pseudomonas sp. Ks-96 isolated from the bioconversion into pyrogallol from gallic acid . Continuous bioconversion of pyrogallol was carried out using rotatory disc contactor immobilized Pseudomonas sp. Ks-96 . Enzyme activity of gallate decarboxylase released from Pseudomonas sp. Ks-96 were shown at the highest activity on 24h incubation. Culture media containing gallic acid supplied on the flow rate of 20m${\ell}$/h until thickness of cells wall reached steady state. Bioconversion rate of pyrogallol from gallic acid showed at highest level ranging from 18hr to 36h according to time courses. Continuous bioconversion of pyrogallol using rotating disc contactor was about 82% and 80% between 6 and 8 days at the feeding rate of 300m${\ell}$ per hour in the medium containing 15g/${\ell}$ gallic acid.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.488-492
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• 2012

Two strains, traditionally referred to as rock flower (Bawhi-kot) and buckwheat flower (Memil-kot or Chile-Kot), were isolated from stored traditional soy sauce and were identified by using the 18S ITS1/4 region sequences. The rock flower strain showed 99% of similarity with Cladosporium sp. and buckwheat flower strain was 99% identical with yeast Sterigmatomyces halophilus. Both strains were tentatively named Cladosporium sp. NK1 and Sterigmatomyces halophilus NK2, respectively. The optimal growth pHs and temperatures of both strains in a YPD broth medium were in the range of pH 5.0 to 7.0 and 22 to $27^{\circ}C$. Both strains were able to grow in more than 20% of NaCl. In the enzyme activity assay, high protease activity of Cladosporium sp. NK1 and S. halophilus NK2 were obtained in YPD containing 10% of NaCl. High amylase activities of both stains were in 15% and 5% of NaCl, respectively. Lipase activity was, however, not detected in both strains.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.673-680
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• 2013

Phosphorus accumulating microorganisms (PAOs) are influenced by various environmental factors and heavy metals. This study was performed to evaluate the effects of the selected heavy metals on the growth and phosphorus removal capacity of Bacillus sp. 3434 BRRJ, Pseudomonas aerunogisa, and Bacillus Subtilis, well known as PAOs. The heavy metals used in this study included Cu, Cd, As, and Zn. The $IC_{50}$ (median inhibition concentration) values of Bacillus sp. 3434 BRRJ for the Cu, Cd, As, and Zn were 8.07 mg $L^{-1}$, 0.18 mg $L^{-1}$, 73.62 mg $L^{-1}$ and 0.25 mg $L^{-1}$, respectively. The $IC_{50}$ values of Pseudomonas aerunogisa for the Cu, Cd, As, and Zn were 4.45 mg $L^{-1}$, 0.16 mg $L^{-1}$, 18.51 mg $L^{-1}$ and 2.34 mg $L^{-1}$, respectively. The $IC_{50}$ values of Bacillus Subtilis for the Cu, Cd, As, and Zn were 3.81 mg $L^{-1}$, 0.18 mg $L^{-1}$, 11.31 mg $L^{-1}$ and 0.47 mg $L^{-1}$, respectively. The phosphorus removal efficiencies of the three bacteria, Bacillus sp. 3434 BRRJ, Pseudomonas aerunogisa, and Bacillus subtilis were 93.12%, 71.81%, and 65.31%, respectively. Based on the results of the three PAOs obtained from the study, it appears that Bacillus sp. 3434BRRJ may have the best results in terms of their growth rate and P removal efficiencies.

• Korean Journal of Environmental Agriculture
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• v.19 no.1
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• pp.13-19
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• 2000

Seasonal variations of dominant algae species and the effects of these algae on coagulation and filteration of water treatment were investigated at Chilseo water treatment plant in downstream of Nakdong river from January in 1995 to Desember of 1998. The water quality of Nakdong river was found to be a hyper eutrophic state during the investigation periods. In the measurement, Chlorophyll-a contents ranged $20.7{\sim}180.9{\mu}g/l$ and total nitrogen contents(T-N) and total phosphorus contents(T-P) exceeded more than 3.4mg/l and 0.1mg/l, respectively. The changes in dominant algae species was in the order of Stepanodiscus sp., Asterionella sp., Melosira sp., Microcystis sp. and Synedra sp. from spring to winter. Microcystis sp. especially, was blooming during summer and Synedra sp. and Stepanodiscus sp. during winter. Although most diatomous algae appeared in the water treatment process caused filter clogging and reduced efficiency of coagulation and sedimentation, Synedra sp. and Stepanodiscus sp were revealed as the main trouble algae. Malfunction of water treatment process caused by Synedra sp. and Stepanodiscus sp. started at the algae concentrations of 800cells/ml and 1,820cells/ml, respectively. When chlorophyll-a content was $18.9{\mu}g/l$, the optimum amounts of coagulant were found to be 40mg/l of Alum and 16mg/l of PACS. Under condition of chlorophyll-a content of $154.1{\mu}g/l$, addition of Alum at the level of 75mg/l and PACS at the level of 35mg/l showed the lowest turibidity. The result indicates that increased amounts of the coagulants should be added for a better water treatment as chlorophyll-a contents increased. Addition of Alum at the amount of 60mg/l and 30mg/l of PACS removed Stepanodiscus sp. algae at the rate of 85% and 83%, respectively. In case of Synedra sp., 50mg/l of Alum and 25mg/l of PACS showed removal rates of 79% and 81%, respectively. Synedra sp. algae at the standing crops of 1,500cells/ml started filter clogging and a filtering process was completely inhibited after 8 hours. At this situation the filter clogging by Synedra sp. algae occurred at the depth of 5cm from the top anthracite layer. On the other, other algae did filter clogging at the depth of 10cm.