• Korean Journal of Microbiology
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• v.11 no.4
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• pp.175-180
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• 1973

This study was attempted to see more clear relationships among the enterobacteria, especially between the intestinal normal flora and pathogenic bacteria. It has been known that some intestinal normal flora produce the bactrial metabolites that are harmful to other enteric bacteria. One of the metabolites is known as colicin, the protein fraction, which possesses certain degree of inhibitory effect against other bacterial growth fraction, whih possesses certain degree of inhibitory effect against other bacterial growth. As a preliminary study for a colicin purification, the antagonistic effect of E, coli to groups of Salmonella and Shigella has been studied by means of in vitro quantitative culture method. 1. E.coli showed definite inhibitory effects aganist both Salmonella and Shigella groups in the mixture of two organisms. 2. The inhibitory effects of E.coli in the E.coli-Salmonella and the E.coli-Shigella mixture occurred from 4 hours incubation following the inoculation. 3. Even the complete inhibition of pathogenic enteric bacterial growth was noticed in the E.coli-Salmonella mixture at overnight incubation. 4. Among the diluted mixtures, 1:100, 1:1,000, and 1:10,000, survival rate of pathogenic enteric bacteria in the mixtures with E.coli showed least affected at the 1:1,000 dilution. 5. It was found that the antagonistic effect aganist groups of Salmonella-shigella was depending upon the groups of the genera.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.139-145
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• 1998

The Neospora sp. was isolated from the brain of 1 calf via continuous in vitro cultivation in Vero cell. Neospora tachyzoites were observed 45 days after inoculation of the homogenized brain suspension into the Vero cell. The isolated parasite (named tentatively as NCKB-1) was morphologically and ultrastructurally similar to the previously reported Neospora sp isolated in cattle (BPA-1, JPA-1). A comparison of the antigenic reactivity of cultivated tachyzoites with polyclonal antisera to Neospora caninum and Toxoplasma gondii confirmed that this protozoal isolate was similar to N caninum. This is the first report of successful isolation of Neospora sp from cattle in Korea.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.396-401
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• 1995

As a part of trials to develop the antitumor agent from tannins isolated from plants, the antitumor activity of peduculagin, an ellagitannin, isolated from Alnus hirsuta var. microphylla was examined in vitro and in vivo. In vitro, the cytotoxicity was determined by 0.4% typanblue dye exclusion method. peduculagin showed the dose-dependent cytotoxicity against human chronic myelogenous leukemia (K-562), human promyelocytic leukemia (HL-60), mouse lymphoid neoplasm (P388), mouse lymphocytic leukemia (L1210) and mouse sarcoma 180(S180) cell lines. $ED_{50}\; values\; (ED_{50})$ of each cell line were 5.30, 0.92, 2.78, 9.35 and $1.38 \mug/ml$ respectively. The most sensitive cell line was HL-60. In vivo, pedunculagin was administered to ICR mouse with the doses of 50 and $100{\;}{\mu}g/ml$intraperitoneally once at 20 days before S180 inoculation. peduculagin showed the antitumor activity and its T/C ratio (%) was 120.82% in the group of both concentrations.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.414-420
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• 2015

Antifungal activities of crude extractum of Nanshancha Seed Cake (NSC), to inactivate postharvest pathogens were investigated. Highest inhibitory rate was found against C. musae, C. gloeosporioides and C. papaya P.Henn, which was much stronger than that by tea saponin. Compared to tea saponin, effects of NSC extractum was relatively weak and similar on C. gloeosporioides Penzig and P. italicum. In an in vivo study, best controlling effects by NSC extractum was found with banana anthracnose disease development, which showed no inhibitory effects by tea saponin. NSC extractum controlled in vitro C. musae growth through directly inhibiting germination rate and germ tube elongation, and causing distortation, rupture and indentation of C. musae mycelium. In banana fruit subject to C. musae inoculation, higher PAL, POD, GLU and CHT activity was observed in banana fruit treated with crude NSC extractum than that of water control fruits. Current study proved the best controlling effects of crude NSC extractum in C. musae in vitro and in vivo development, which through direct inhibition of C. musae growth and increasing defense system of the banana fruit.

• The Plant Pathology Journal
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• v.32 no.5
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• pp.469-480
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• 2016

Bacterial wilt and grey mould in tomato plants are economically destructive bacterial and fungal diseases caused by Ralstonia solanacearum and Botrytis cinerea, respectively. Various approaches including chemical and biological controls have been attempted to arrest the tomato diseases so far. In this study, in vitro growths of bacterial R. solanacearum and fungal B. cinerea were evaluated using four different vitamins including thiamine (vitamin B1), niacin (vitamin B3), pyridoxine (vitamin B6), and menadione (vitamin K3). In planta efficacies of the four vitamin treatments on tomato protection against both diseases were also demonstrated. All four vitamins showed different in vitro antibacterial activities against R. solanacearum in dose-dependent manners. However, treatment with 2 mM thiamine was only effective in reducing bacterial wilt of detached tomato leaves without phytotoxicity under lower disease pressure ($10^6$ colony-forming unit [cfu]/ml). Treatment with the vitamins also differentially reduced in vitro conidial germination and mycelial growth of B. cinerea . The four vitamins slightly reduced the conidial germination, and thiamine, pyridoxine and menadione inhibited the mycelial growth of B. cinerea. Menadione began to drastically suppress the conidial germination and mycelial growth by 5 and 0.5 mM, respectively. Grey mould symptoms on the inoculated tomato leaves were significantly reduced by pyridoxine and menadione pretreatments one day prior to the fungal challenge inoculation. These findings suggest that disease-specific vitamin treatment will be integrated for eco-friendly management of tomato bacterial wilt and grey mould.

• Journal of Life Science
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• v.12 no.2
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• pp.61-74
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• 2002

One of the major aims in studying plant viruses is to minimise the development of symptoms in infected plants. With the advent of in vitro transcript mediated research on plant viruses, substantial progress has been made. This article describes the biology of a plant specific RNA virus, Johnsongrass mosaic virus (JGMV), important to Australian sorghum and corn agriculture and, in particular, at a molecular level which of the RNA sequences in its genome that make it possible for the virus to move from cell to cell, and eventually spread systemically throughout the entire plant. The JGMV has caused considerable yield losses in maize and sorghum over a number of years in Australia. Incidents where 100% of the crop has been infected are on record. The use of this virus is convenient under laboratory conditions because it can be readily transmitted by mechanical inoculation with infected leaf sap, which obviates the need for maintaining aphid colonies. The JGMV is a single stranded positive sense RNA virus.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.387-393
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• 2000

The process by which Agrobacterium tumefaciens genetically transforms plants involves a complex series of reactions communicated between the pathogen and the plants. To identify plant factors involved in agrobacterium-mediated plant transformation, a large number of T-DNA inserted Arabidopsis thaliana mutant lines were investigated for susceptibility to Agrobacterium infection by using an in vitro root inoculation assay. Based on the phenotype of tumorigenesis, twelve T-DNA inserted Arabidopsis mutants(rat) that were resistant to Agrobacterium transformation were found. Three mutants, rat1, rat3, and rat4 were characterized in detail. They showed low transient GUS activity and very low stable transformation efficiency compared to the wild-type plant. The resistance phenotype of rat1 and rats resulted from decreased attachment of Agrobacterium tumefaciens to inoculated root explants. They may be deficient in plant actors that are necessary for bacterial attachment to plant cells. The disrupted genes in rat1, rat3, and rat4 mutants were coding a arabinogalactan protein, a likely cell wall protein and a cellulose synthase-like protein, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1273-1283
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• 2020

Objective: This study investigated a method of preparing corn stover for Irpex lacteus (I. lacteus) treatment to improve its in vitro rumen degradability under non-sterile conditions. Methods: Corn stover was inoculated with Lactobacillus plantarum (L. plantarum), Lactobacillus buchneri (L. buchneri), and an equal mixture of these strains, and ensiled for 0, 3, 7, 14, and 28 days. After each period, a portion of the silage was sampled to assess the silage quality, and another portion of the silage was further treated with I. lacteus at 28℃ for 28 d. All the samples were analyzed for fermentation quality, chemical composition, and in vitro gas production (IVGP) as a measure of rumen fermentation capacity. Results: Lactic acid bacteria (LAB) was found to improve the silage quality of the corn stover, and the corn stover silage inoculated with L. plantarum produced more lactic acid and higher IVGP than other silage groups. The I. lacteus colonies flourished in the early stage of corn stover silage, especially on the 3-d corn stover silage inoculated with both L. plantarum and L. buchneri. This led to an 18% decrease in the acid detergent lignin content, and a 49.6% increase in IVGP compared with the raw stover. Conclusion: The combination of ensiling with the mixed LAB inoculation and I. lacteus treatment provided a cost-effective method for the improvement of the IVGP of corn stover from 164.8 mL/g organic matter (OM) to 246.6 mL/g OM.

• Parasites, Hosts and Diseases
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• v.37 no.2
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• pp.121-125
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• 1999

Inoculation of human fecal cysts to suckling Mongolian gerbils, two Giardia lamblia isolates, Kl and K2, were established as axenic cultures. Using this in vitro culture, both two Giardia isolates were grouped by using two genetic analysis. With genetic analysis of SSS-rDNA sequences, both K1 and K2 were found as members of hopkins'group 1, despite some nucleotide differences noticed in K1 (5 differences/292 bases.). The other genetic study used PCI-RFLP of the tim (triose phosphate isomerase) Nash's group 2 can bot be a separate group, but a part of Hopkins' group 1.

• Parasites, Hosts and Diseases
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• v.38 no.4
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• pp.257-261
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• 2000

This study was focused on the effects of microfilament inhibitor, Cytochalasin D (CD) on the invasiveness of sporozoites of Cryptosporidiun spp. into the host cells. MDCK and AGS cell lines were used as host cells for C. parvum and C. muris, respectively. When MDCK cells were pretreated with CD for 1 hr before inoculation of the sporozoites, C. parvum infection was significantly inhibited when compared to the control cells. These inhibitory effects of CD on the rate of infection were dose-dependent. In addition, C. muris infection was hampered when AGS cell lines were pretreated with CD. However, the capability of invasiveness of the sporozoites into the host cells was not greatly influenced by the pretreatment of sporozoites with CD before infection. These results suggest that microfilaments of host cells, rather than parasites, play an important role for the invasion of Cryptosporidium spp.