• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.38-41
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• 2001

It has been reported that some plants have the potential to metabolize the 2,4,6-trintroluene (TNT) in contaminated soils, sediments and natural water. In this study, the effects of TNT on germination and early seedling development of Abutilion avicennae was characterized in a germination test. Concentration up to 80 mg/L TNT did not affect germination but root and shoot growth, and fresh biomass decreased as TNT concentration increased. A series of axenic hydroponical batch culture of Abutilion avicennae at various initial TNT concentration was used to determine its transformation kinetics, to identify products formed, and to evaluate phytotoxic effects on the TNT transformation process. At higher initial TNT concentrations, TNT removal rate constant decreased, however, total amount of TNT removed was increased in the culture media. Reductive transformation products of TNT were not detected in the plant culture media but higher concentrations of reduced metabolites were detected in the root and stem extracts of plant material at the 7 days of batch incubation. From these results we concluded that Abutilion avicennae has an intrinsic capacity for taking up and transforming TNT.

• Research in Plant Disease
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• v.9 no.1
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• pp.42-46
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• 2003

Conidiomata of the Rosellinia necatrix were induced in axenic culture under near ultraviolet light radiation. Pieces of sterilized Japanese pear twigs were placed on the 7 days-old oatmeal agar culture in plates. The plates were further incubated far 5 days and then illuminated by under near ultraviolet light radiation. Syn-nemata were developed on twigs in 19 out of 20 isolates tested within 5 weeks, and conidia were observed in 12 out of the 19 isolates. The synnemata and conidia produced were morphologically identical to those of Dematophora necatrix.

• Korean Aquaculture
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• v.12 no.1
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• pp.95-99
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• 2000

이번 호에서는 먹이생물 관련 양식 정보 시리즈 여섯 번째로 수산 증양식 분야에서 어린 유생의 먹이로서 이용되는 식물${\cdot}$동물 먹이생물의 배양 방법으로서 배량 배양으로 들어가기 전에 선결되어야 할 단일종 배양, 스트레스 배양 그리고 무균 배양에 대하여 기술한다.

• Journal of Microbiology
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• v.33 no.3
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• pp.208-214
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• 1995

The effects of various 2, 4-D-degradative plasmids on the axenic growth patterns, the degradation phenotypes, and the competitiveness of different host bacteria were evaluated in liquid cultures; the organisms and plasmids used were Alcaligenes eutrophus JMP134/pJP4, Alcaligenes paradoxus/p2811, Pseudomonas pickettii/p712, pJP4, and p712 or p 2811 exhibited very different restriction fragment profiles in restriction endonuclease digests. These plasmids were transferred to the recipients (P. cepacia and Alcaligenes JMP228) at relatively high frequencies ranging from 8.9 $\times$ 10$^3$ to 1.6 $\times$ 10$^5$ per donar cell. In the axenic liquid cultures the fast-growing strains, such as P. pseudomallei/p745 and P. cepacia/pJP4, exhibited short lag periods, high specific growth rates, and high relative fitness coefficients, while the slow-growing strains, such as P. pickettii/p712 and A. paradoxus/p2811, had long lag periods, low specific growth rates, and low relative fitness coefficients. Depending on the type of plasmid containing the genes for the 2, 4-D pathway, some transconjugants exhibited intermediate grwoth patterns between the fast-growing strains and the slow-growing strains. The plasmid and plasmid-host interactions determined specific growth rate and lag time, respectively, which were shown to be principal determinants of competitiveness among the strains, but relative fitness coefficient derived from the axenic culture was not always predictive for the mixed culture condition.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.313-314
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• 2002

• Journal of Life Science
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• v.25 no.5
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• pp.568-576
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• 2015

The marine microalga Pavlova viridis can grow fast and has the ability to accumulate essential nutrients for culturing marine animals, such as EPA and DHA, and it has been used as food for raring larval fish and prawn. The symbiotic relationship between the flagellate microalga Pavlova viridis and its associated bacteria was investigated. An axenic culture of P. viridis was obtained by repeated treatment of the microalga with an antibiotic cocktail. The axenic status was confirmed after sub-culturing three times in a sterile f/2 medium without an antibiotic. The axenic alga was then co-inoculated with five bacteria, arbitrarily designated as I1–I5, isolated from the alga to test the growth promotion of the algae. All bacterial strains promoted the growth of P. viridis, and bacterial isolate I3 was the most effective among the five bacteria tested. The cell number of P. viridis in the co-culture with I3 was significantly higher than that of the control culture. A sequence analysis of the 16S rRNA gene isolated from I3 revealed a 97% nucleotide sequence similarity to that of Citrobacter sp. The growth of strain I3 was also significantly enhanced by co-culturing with P. viridis, indicating a symbiotic relationship between the microalga and its associated bacterium. The association between the microalga and bacterium was confirmed by scanning electron microscopy.

• Journal of Plant Biotechnology
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• v.7 no.3
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• pp.169-174
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• 2005

The optimal culture conditions were studied for plant regeneration from mesophyll protoplasts of Solanum sisymbriifolium. Axenic seedlings of S. sisymbriifolium were used as a explant for protoplast culture. Many viable protoplasts were isolated by incubating leaf slices in an enzyme solution containing 0.25% Meicerase and 0.05% Macerozyme for 16 hr at $25^{\circ}C$ without shaking. Protoplast density of $5.0{\times}10^4\;ml^{-1}$ in Kao medium containing 5.0 mg/L NAA, 1.0 mg/L 2,4-D and 1.0 mg/L BA was optimal for colony formation. Most colonies were formed when protoplasts were cultured at $25^{\circ}C$ after initial culture at $30^{\circ}C$ for one week. On the MS agar medium with 1.0 mg/L zeatin, 38.4% of protoplast-derived calli differentiated shoots. These shoots rooted on 1/2MS medium with 5.0 g/L sucrose and 2.5 g/L gellan gum, and developed into whole plants.

• Mycobiology
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• v.38 no.3
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• pp.225-228
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• 2010

We studied the resistance of Cenococcum geophilum and Suillus granulatus isolates to NaCl during growth under axenic culture conditions. C. geophilum isolates displayed variations in NaCl resistance; mycelial growth of most isolates was inhibited above 200mM. All isolates of S. granulatus were tolerant to high NaCl content.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.75-78
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• 2003

A lichen-forming fungus was successfully isolated by discharged spore method from Korean lichen (Hetero-dermia sp.) and cultivated in pure culture. The isolate JR0012 inhibited mycelial growth of several plant-pathogenic fungi. Mycelial growth of the four Pythium spp. tested was completely inhibited. Potato dextrose broth was found to be the medium favorable for large-scale production of antibiotics from the isolate. Anti-fungal substances produced in axenic culture were partially purified. This is the first report in Korea of lichen-forming fungus successfully isolated and which exhibited strong antifungal activity against plant-pathogenic fungi, especially the four Pythium spp..

• Parasites, Hosts and Diseases
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• v.56 no.1
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• pp.71-74
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• 2018

Soluble antigens from an axenic culture of Entamoeba histolytica were used to develop a commercial ELISA kit to quantify anti-E. histolytica antibodies in sera of patients with extraintestinal amebiasis in non-endemic settings. The diagnostic specificity and sensitivity of the test were assessed retrospectively using 131 human serum samples with amoebic serologic status available. They were selected according to their results in immunofluorescence (IFAT) and were separated in 2 sample categories: 64 sera with positive results by IFAT and 67 with negative results by IFAT. The sensitivity and specificity of the ELISA kit were assessed at 95.0% and 94.0% compared to the IFAT. The test can be useful to exclude a potential diagnosis of amebiasis and could be used as a screening method since ELISA is an automated technique.