• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.335-339
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• 1998

The factors affecting the isolation and culture of the protoplast of embryogenic callus, derived from immature ovule in Citrus junos, were examined. An incubation time in enzyme solution of 16 hrs was preferable for protoplast isolation. Efficient protoplast yields were obtained from the treatment of equal concentration of 0.7 M $\textrm{BH}_{3}$ to the enzyme solution containing 1.0% cellulase, 1.0% macerozyme and 0.2% pectolyase. Protoplast cultured in MT medium with 0.1 mg/L 2,4-D showed vigorous division and some of them formed callus. Induced callus was subcultured on solid MT medium but the callus showed very slow growth. The above results show the possibility to culture from protoplast fusion in Citrus genera.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.260-267
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• 2023

We aimed to investigate the proportions of MTB- and NTM-positive tests and the distribution patterns of species isolated by contracted testing agencies in South Korea. Respiratory specimens submitted to contracted testing agencies in South Korea for AFB culture from January 2014 to December 2021 were included (533,713 specimens in total). Trends based on MTB and NTM detection, patient sex and age, culture medium type, and testing year were analyzed. MTB and NTM positive detection increased in the patients. The average ages of MTB- and NTM-positive patients increased in those aged ≥61 years. For solid culture, the MTB detection rate decreased from 5.9% in 2014 to 3.3% in 2018 and increased to 4.7% in 2021; the NTM detection rate increased from 2.1% in 2014 to 3.4% in 2018 and 3.7% in 2021. For liquid culture, the MTB detection rate decreased from 8.3% in 2014 to 5.5% in 2018 and increased to 6.0% in 2021; the NTM detection rate increased from 3.5% in 2014 to 5.5% in 2018 and decreased to 5.3% in 2021. An isolation ratio reversal between MTB and NTM was observed in 2018. In this study, we provide information on mycobacterial isolation rates and species distributions using AFB culture test results from Korea's referral laboratories. Increased MTB- and NTM-isolation rates were observed in individuals aged ≥60 years, indicating the need for regular testing and focused management for them. Expanding liquid culture applications, which show higher positivity rates than solid culture methods, is necessary.

• Journal of Korean Living Environment System
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• v.25 no.1
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• pp.90-97
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• 2018

The purpose of this study is to compare and analyze the air infections in middle and small hospitals with the facilities of large national hospitals that have air-borne infection isolation (AII) wards through actual condition investigation and airflow analysis simulation (CFD) and to provide basic data for prevention. The method and scope of the study are as follows. First, through literature review, data related to prevention of infection spread in domestic medical institutions were investigated. Second, we conducted a survey on the status of isolation facilities to prevent the spread of infectious diseases in large hospitals and small and medium - sized clinics in Korea. Third, airflow analysis simulation (CFD) was carried out using the isolation ward of the nationally designated inpatient ward and the data of the plane and facility system of the small clinic. As a result of the study, it is found that regulations applicable to small and medium-sized clinics are insufficient. In addition, the simulation results show that the infectious disease virus is likely to spread to other patients in the hospital.

• The Journal of the Korean Society for Microbiology
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• v.10 no.1
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• pp.33-37
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• 1975

In view of the warmth and hunidity in Korea, there is little possibility to avoid the fungal contamination of rice soybean paste which are major foodstuffs in this country. In order to isolate aflatoxin producing fungi from these foodstuffs, 6 samples of rice were collected from the farmhouses at Cbangsung and 40 samples of soybean paste in Seoul areas. The peptone glucose chloramphenicol, Czapek-Dox agar and malt agar were used for the isolation and identification of fungi, and Adye and Meteles medium and/or Sahouraud medium for the production of toxins. The cultures for the toxin production were done at $25^{\circ}C$ for $5{\sim}7$ days. Eleven Penicillium species were isolated. from 6 samples of rice, and 37 Aspergillus flavus, 48 Aspergillus species, 1 Penicillium species and 105 others were isolated from 40 samples of soybean paste. Among these, one Penicillium species isolated from rice was found to be aflatoxin producing strain, and the toxin was quantitatively measured. Aflatoxin appeared to be more favorably produced in the glucose Sabouraud medium than in the Adye and Meteles medium.

• Animal cells and systems
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• v.2 no.2
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• pp.239-242
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• 1998

Arabidopsis trp1 mutant plants, deficient in phosphoribosyI anthranilate transferase (PAT) activity, accumulate anthranilate compounds, which render them blue fluorescence. The visible phenotype of trp1 makes the PAT gene an excellent reporter gene in the mutant. In order to develop a system for the homologous recombination using the phenotypic characteristic of trp1-100, we established optimum conditions for the isolation and regenera tion of protoplast from auxin-conditioned, trp1-100 root cultures. Trvptophan had to be supplemented in the germination medium for the efficient cell division and subsequent plant regeneration. When 10 uM tryptophan was added to the germination medium, we obtained the highest yield of protoplasts ($3{\times}10^6 cells/g$) and the best viability (92%). Thirty percent of root protoplast derived from meristematic cells underwent cell division within 5 days in callus-induction medium. Regenerated rosette leaves (2-3 mm) were transferred to rooting medium and finally acclimated to the soil for flowering.

• Journal of Dairy Science and Biotechnology
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• v.42 no.1
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• pp.9-17
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• 2024

This study aimed to evaluate the appropriateness of MRS-C (0.05% L-cystein; pH 5) and BHI-CM (0.05% L-cystein, 0.5% mucin) agars for the selective isolation of bifidobacteria in fecal samples compared to blood-liver-NPNL (BL-NPNL) agar. Over 200 isolated colonies were characterized morphologically and biochemically. Genomic DNA was extracted from pure cultures of the isolated strains, followed by PCR amplification of the 16S rRNA gene. Bifidobacterium longum and B. animalis were selectively isolated from MRS-C agar and Lactobacillus acidophilus and Enterococcus avium were also isolated. B. longum, B. faecale, and B. animalis were isolated from feces on BHI-CM agar; however, different Bacteroides strains (including Bac. fragilis, Bac. kiribbi, Bac. ovatus, Bac. koreensis, and Bac. salyersiae) were also detected. BL-NPNL agar successfully isolated B. longum and Bacillus, while other Bifidobacterium and Bacteroides species could not grow owing to the presence of antibiotics in the medium. The use of antibiotics in a medium can enhance the selectivity; however, antibiotics may inhibit the growth of certain bacteria in a sample. Hence, adjusting pH or adding non-antibiotic nutrients to the medium is more advantageous, than relying on antibiotics.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.279-284
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• 1996

To develop a selective medium for the isolation and the detection of leuconostocs from the various samples including fermented vegetables, ten strains of leuconostocs and seven strains of lactobacilli were tested for their sensitivity to various antibiotics. The basal-medium containing 5 ${\mu}g/ml$ of novobiocin inhibited the growth of lactobacilli completely, but not that of leuconostocs. On the basis of this result, a new selective medium was developed and to be named NLS medium. This medium contains 1% Tryptone (Difco), 0.1% Yeast Extract (Difco), 2% sucrose, 0.1% Beef Extract (BBL), 0.5% sodium acetate, 0.2% ammonium sulfate, 0.01% magnesium sulfate, 0.2% dipotassium phosphate, 0.05% sorbic acid, 75 ppm sodium azide (Sigma), 0.1% (vol/vol) Tween 80, 30 ${\mu}g/ml$ of Vancomycin (Sigma), 5${\mu}g/ml$ of Novobiocin (Sigma), 0.5${\mu}g/ml$ of cysteine HCI, and 1.5% Agar (Difco). All of the eighty six isolates obtained from some foodstuffs were identified as members of the genus Leuconostoc. Comparative counts with the MRS, PES, LUSM, and NLS medium indicated that the recovery percent was lower than other selective media. Therefore, this result suggested that NLS medium was suitable for the isolation of leuconostocs, but not for counting or enumerating.

• The Korean Journal of Mycology
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• v.22 no.2
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• pp.130-137
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• 1994

This experiment was carried out to investigate proper conditions for protoplast isolation and regeneration from mycelia of Lyophyllum decastes. Novozym 234(10 mg/ml) with 0.6 M $MgSO_4$ in phosphate buffer(pH 4.0) was proper for protoplast isolation. The optimal reaction time of the mycelium with the lytic enzyme was four hours in shaking condition at 120 strokes per min. When the mycelium of L. decastes was cultured at $24^{\circ}C$ for 5 days, the formation of protoplasts was effective. The liquid medium was more effective for protoplast isolation than the solid medium. In the liquid medium, high yields of protoplasts were obtained from 0.6 M $MgSO_4$ osmotic stabilizer. Protoplasts of L. decastes were regenerated to normal hyphal growth and the regeneration frequency of the protoplasts in the complete agar medium containing Triton X-100(0.0025%) was $5.94{\sim}8.32%$. The regeneration medium stabilized with 0.6 M sucrose was the best for regeneration of the protoplasts. In contrast to protoplast formation, regeneration was inhibited by the inorganic salts used as osmotic stabilizer.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10b
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• pp.20-20
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• 2003

Isolation and culture of leaf protoplasts from two chilli cultivars (Capsicum annuum var. accumnatum and Bird chilli) were developed to enhance selection process in the somatic hybridization programmes. In order to isolate the protoplasts from leaves of these two chilli cultivars different incubation periods (3, 5 and 10 hours) were tested with combinations of enzyme mixtures containing cellulase and macerozyme. Leaves were incubated on three enzyme mixtures (2% cellulase +0.4% macerozyme, 1% cellulase +0.2% macerozyme and 0.5% cellulase +0.1% macerozyme in 13% mannitol) at 251oC in the dark. Three hours of incubation using 2% cellulase and 0.4% macerozyme was the best for the protoplast isolation of both chilli cultivars tested. The yield was 5${\times}$108protoplasts/m1/g leaf tissue in both chilli varieties. It was found that in the mixed nurse method using Nagata and Takebe (NT) medium supplemented with 1.0mg/12,4-D, NAA and BAP with 0.5M mannitol and 1.2% Sea Plaque agarose is the best medium for protoplast culture. Protoplasts of Capsicum annum var. accumnatum were alive for 14 days forming cell walls and initiating cell division.

• The Journal of the Korean Society for Microbiology
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• v.35 no.4
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• pp.309-316
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• 2000

This study was focused on the isolation of pathogenic Vibrio species, V. vulnificus and V. parahaemolyticus from marine environment from May to July of 1999. Isolation sites were coast near by Pusan and Daechon. The results obtained were as follows: 1. Seventy strains of V. parahaemolyticus and 19 strains of V. vulnificus were isolated from a total of 120 specimens. 2. Nineteen strains of V. vulnificus did not fermented arabinose and salicin but fermented lactose and cellobiose. All of V. parahaemolyticus isolates did not fermented lactose and cellobiose. 47 strains of V. parahaemolyticus fermented arabinose but 53 strains did not fermented salicin. 3. V. vulnificus and V. parahaemolyticus isolates showed three different API index numbers with 5046105 and 4346107 dominant. 4. V. vulnificus did not grow on 0% and 8% NaCl containing medium. V. parahaemolyticus grew on 8% NaCl containing medium. 5. V. vulnificus isolates and V. parahaemolyticus revealed different outer membrane protein profiles on SDS-PAGE.