• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.209-214
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• 1992

Serratia marcescens co-cultured with various phytopathogenic fungi, including Rhizopus stolonifer, Helminthosporium allii, Pyricularia oryzae, Fusarium oxysporium and Collectothricom cassiicola, in an LB- agar medium containing 1.5% swollen chitin, significantly inhibitied fungal growth. Fungal hyphae grew rapidly outward from the culture dish center, but the hyphal extensions of the pathogenic fungi were significantly inhibited in a perimetric contact area with S. marcescens. This was especially evident in pathogenic fungi which have a high chitin content in their cell walls. The extracellular chitinase activities of S. marcescens were increased seven fold by the addition of 1.5% swollen chitin to the LB-broth, compared to chitinase activities in a culture medium without chitin. The type of induction was dependent on the various forms of chitin used. When the culture supernatant of S. marcescens or the chitinases of Streptomyces griceus purchased from Sigma Chemical Co., were incubated with the mycelium of F. oxysporium, the mycelium gradually burst as cultivation time progressed and completely lysed after incubation for 2 days. On the other hand, E. coli extract did not hydrolyze the F. oxysporium mycelium at all. These data showed that the chitinolytic activities of S. marcescens play important roles in the biochemical control of phytopathogenic fungi.

• Reproductive and Developmental Biology
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• v.29 no.4
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• pp.241-245
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• 2005

Porcine oviduct epithelial cells (POEC) are widely used in co-culture experiments to improve early embryonic development, in vitro fertilization in embryo transfer programs for domestic animals and in vitro maturation of immature germ cells. POEC were mechanically isolated and cultured in tissue culture medium 199. Cells grew continuously, and confluent monolayers were formed after 7 days. After forming confluent monolayer of epithelial cells, supernatant was collected as the condition medium for maturing round spermatids in vitro. Round spermatids were also separated mechanically and cultured in the POEC condition medium. In this study we observed that $20\%$ of round spermatid cultured were matured into elongating spermatid after 24 h, and about $10\%$ of round spermatid cultured showed complete elongation (elongated spermatid) within $24\~48$ h of in vitro culture. No further development was observed within $50\~72$ h and transformed cells lost their viability after 72 h. These preliminary findings suggest that the condition medium from POEC may be possible to overcome the round spermatid block by improving the milieu of culture system.

• Journal of Embryo Transfer
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• v.33 no.1
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• pp.41-48
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• 2018

In the last several decades, cell therapy research has increased worldwide. Many studies have been conducted on cell therapy, and have revealed that transplanted cells did not survive for long, and implanted cells remained inactive causing immune rejection depending on the patient's condition. Therefore, studies on cell-free therapy need to be conducted. To overcome these limitations, an alternative is the use of supernatant from cells, called "conditioned media (CM)." During in vitro cell culture, culture media supply nutrients to maintain cell characteristics and viability. In the culture, cells not only consume nutrients but also release beneficial proteins and substances, which are called "secretome." CM from cells can be stored for a long time and is easy to handle. Moreover, secretome in CM can also be measured; exact amount of secretome is important to set the standard value for disease treatment. Here, we reviewed studies on CM and confirmed that various secretomes from CM were identified in these studies. Moreover, these findings could benefit cell and animal studies in future. In conclusion, CM could be a potential candidate for an alternative to cell therapy.

• Journal of Veterinary Clinics
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• v.28 no.2
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• pp.183-189
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• 2011

The objective of this study was to examine the effect of fucoidan on the phagocytic capapcity and oxidative burst activity (OBA) of canine peripheral blood polymorphonuclear cells (PMNs). The phagocytic capacity and OBA of PMNs were evaluated simultaneously by using a flow cytometer. Fucoidan itself did not cause any direct effect on the phagocytic capacity and OBA of PMNs. However, the phagocytic capacity and OBA of PMNs were enhanced by the culture supernatant from PBMCs treated with fucoidan. The phagocytic capacity and OBA of PMNs were also increased by treatment with recombinant canine (rc) tumor necrosis factor (TNF)-${\alpha}$. The ability of the culture supernatant from fucoidan-treated PBMCs to stimulate the phagocytic capacity and OBA of PMNs was inhibited by addition of anti-rc TNF-${\alpha}$ polyclonal antibody (PAb) prior to the culture. The amount of TNF-${\alpha}$ in the culture supematant from PBMCs was shown to increase upon treatment of fucoidan as compared with that of vehicle-treated PBMCs culture supematant. The level of TNF-${\alpha}$ mRNA expression in PBMCs was also up-regulated by the fucoidan treatment. These results suggest that fucoidan has an immunoenhancing effect on the phagocytic capacity and OBA of canine PMNs, which is mainly mediated by TNF-${\alpha}$ released from fucoidan-stimulated PBMCs.

• Journal of Life Science
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• v.11 no.5
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• pp.439-446
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• 2001

Leuconostoc mesenteroides subsp. cremoris DLAB19 were investgated under various culture conditions to maximize the production of antimutagenic substance(s) against N-methyl-N\`-nitro-N-nitrosoguandine(MNNG) on Salmonella enterica serovar typhimurium TA100 and 4-nitroquinoline-1-oxide(4-NQO) on S. enterica serovar typhimurium TA98. The MRS medium containing glucose (2%) as a carbon source and yeasty extract (1%) as a nitrogen source resulted in the highest production of the antimutagenic substance(s) against both mutagens in the culture supernatant of Leu. mesenteroides subsp. cremoris DLAB19. Optimal pH of the culture medium, culture temperature and shaking speed for the antimutagenic substance(s) production were pH 7.0, 3$0^{\circ}C$ and 150 rpm, respectively. Under the optimal condition, the antimutagenic effects of Leu. mesenteroides subsp. cremoris DLAB19 culture supernatant were 96.4% against MNNG on S.enterica serovar typhimurium TA100 and 53.8% against 4-NQO on S. enterica serovar typhimurium TA98.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.549-557
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• 2000

Dental caries is a bacterial disease of the dental hard tisssus, characterized by a localized, progressive, molecular disintegration of tooth structure. The action of Leuconostoc lactis 51 about plaque formation and replication by Streptococcus mutans was studied as follows. 1. Lower amount of plaque was produced at the mixed culture of S. mutans and L. lactis 51 than S. mutans alone on the wires in the beaker. 2. Fewer cells of S. mutans were replicated at the mixed culture of S. mutans and L. lactis 51 than S. mutans alone. 3. In M17Y broth, viable cells of S. mutans and L. lactis 51 increased for 12 hours, and decreased for 24 hours. In M17YS broth, viable cells of S. mutans showed time-dependent decrease at mixed culture of S. mutans and L. lactis 51. 4. The culture supernatant of L. lactis 51 didn't inhibit the replication of S. mutans and the formation of artificial plaque. 5. Sucrose and frutose were extracted from the culture supernatant of L. lactis 51 in M17YS broth. These results suggest that L. lactis 51 isolated from the oral cavity inhibits the replication of S. mutans and the formation of artificial plaque.

• Biotechnology and Bioprocess Engineering:BBE
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• v.4 no.1
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• pp.12-16
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• 1999

Xenorhabdus nematophilus sp., an insect-pathogenic bacterium, was newly isolated from Korean entomopathogenic nematode of Steinernema carpocapsae, which can be used as a useful bioinsecticide. Primary and secondary form variants of Xenorhabdus nematophilus were observed when cultured in vitro. Primary form variants adsorbed bromothymol blue, while secondary form did not. However, many other characters of two variants were very similar. The variants were all rod-shaped and cell size was highly variable ranging from 0.5 by 2.0 ${\mu}$m to 1.0 by 5.0 ${\mu}$m. Both produced highly toxic substances and killed the insect larva within 20∼38 hr, indicating that insect pathogenicity of Xenorhabdus is not directly associated with its phase variation. In addition, cell-free culture supernatant of Xenorhabdus was sufficient to kill the insect larva by injecting it ito insect hemolymph; however, cell-harboring culture broth was more effective for killing the insect. The use of Xenorhabdus nematophilus may provide a potential alternative to Bacillus thuringiensis (Bt) toxins.

• Journal of Microbiology and Biotechnology
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• v.3 no.2
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• pp.65-72
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• 1993

A heterologous gene expression and secretion system using a methylotrophic yeast, Hansenula polymorpha was developed for the production of anticoagulant hirudin. Hirudin gene was expressed under the control of a strong and inducible methanol oxidase (MOX or AOX) promoter. The mating factor a pre-pro leader sequence of Saccharomyces cerevisiae was employed for hirudin to be secreted into the extracellular medium. Hirudin expression cassette was introduced into three strains of H. polymorpha, A16, HPBl and DLl which have different genetic backgrounds. This expression cassette was stably integrated into the host chromosomal DNA. Biologically active and mature hirudin was efficiently expressed and secreted into the extracellular medium. About 19 mg/L of hirudin was found in the culture supernatant in the case of a two-copy integrant of the strain HPBl under suboptimal culture conditions.

• Preventive Nutrition and Food Science
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• v.17 no.1
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• pp.64-70
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• 2012

Bacilli with fibrinolytic activities were isolated from traditionally-prepared Meju and some of these strains showed strong antifungal activities. One isolate, MJ1-4, showed the strongest antifungal activity. MJ1-4 and other isolates were identified as B. amyloliquefaciens strains by recA gene sequencing and RAPD-PCR results. B. amyloliqufaciens MJ1-4 efficiently inhibited an Aspergillus spp.-producing aflatoxin B1 ($AFB_1$) and a Penicillium spp.-producing ochratoxin (OTA) in addition to other fungi. Antifungal activity of B. amyloliquefaciens MJ1-4 culture reached its maximum (40 AU/mg protein) in LB or TSB medium around 48 hr at $37^{\circ}C$. Antifungal activity of the concentrated culture supernatant was not decreased significantly by protease treatments, implying that the antifungal substance might not be a simple peptide or protein. Considering its antifungal and fibrinolytic activities together, B. amyloliquefaciens MJ1-4 can serve as a starter for fermented soyfoods such as Cheonggukjang and Doenjang.

• Microbiology and Biotechnology Letters
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• v.25 no.6
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• pp.546-551
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• 1997

A bacterium producing the extracellular cellulases was isolated from soil and has been identified as Bacillus sp. The isolate, named Bacillus sp. 79-23, was shown to be very similar to B. subtilis on the basis of its biochemical properties. The carboxymethyl cellulase (CMCase) of culture supernatant was most active at 60$\circ$C and pH 6.0, and retained 90% of its maximum activity at pH 7.0. The additional carbon sources affected the CMCase productivity than nitrogen sources in the culture medium. The carbon sources including wheat bran, rice straw, maltose and glucose increased the enzyme productivty. Especially, the maximum CMCase production was 5.2 units/ml in LB medium supplemented with 3% (w/v) wheat bran, which was 13-folds more than that in LB medium. It was found that the enzyme production was in association with the growth of Bacillius sp. 79-23. But, whean bran did not affect the growth of isolate, suggesting that increasement of CMCase production was owing to the induction of CMCase biosynthesis by wheat bran. In addition, both water-soluble and insoluble components of wheat bran was involved in induction of CMCase biosynthesis.