• Journal of agriculture & life science
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• v.50 no.5
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• pp.81-93
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• 2016

Rehmannia glutinosa(Gaertn.) DC. is a herbaceous perennial plant and belonging to the Scrophulariaceae and used as roots for medicinal part and purpose. R. glutinosa is and usually used for fresh rehmannia root or prepared rehmannia root. However, it is very difficult to propagate using the seeds because of lack germination so it is propagated using the vegetative method as the rootstock. Currently, propagation and harvesting using the rootstock of R. glutinosa has difficulties about production of the high quality and quantity in R. glutinosa because of root rot disease. To optimize in vitro cultures and to improve the rootstock and seedling of R. glutinosa after morphological and genetical determination, 5 plant culture media (MS, DJ, LS, QL, and WPM) were used in this study then WPM was selected for better growth, for multiplication condition(WPM + IAA 1.0 mg/L + IBA 0.5 mg/L), and for root enlargement condition(WPM + NAA 0.1 mg/L) of R. glutinosa. Based on these results, in vitro seedlings of R. glutinosa were transferred to soil for acclimation with environment adaptation and shown the positive effects about root enlargement and root formation. Therefore, it can be used for high quality of R. glutinosa production and production of the rootstock based on propagation using in vitro seedlings of R. glutinosa.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.259-268
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• 2023

Rhodococcus sp. 3-2 strain has been reported to degrade benzimidazole-based pesticides, such as benomyl and carbendazim. Therefore, this study aimed to optimize culture medium composition and culture conditions to achieve cost-effective and efficient large-scale production of the Rhodococcus sp. 3-2 strain. The study identified that the optimal media composition for mass culture comprised 0.5% glucose, 0.5% yeast extract, 0.15% NaCl, 0.5% K₂HPO₄, 0.5% sodium succinate, and 0.1% MgSO₄. Additionally, a microbial agent was developed using a 1.5-ton fermenter, with skim milk (20%), monosodium glutamate (15%), and vitamin C (2%) as key components. The storage stability of the microbial agent has been confirmed, with advantages of low temperature conservation, which helps to sustain efficacy for at least six months. We also assessed the benomyl degradation activity of the microbial agent within field soil. The results revealed an over 90% degradation rate when the concentration of viable cells exceeded 2.65 × 10⁶ CFU/g after a minimum of five weeks had elapsed. Based on these findings, Rhodococcus sp. 3-2 strain can be considered a cost-effective microbial agent with diverse agricultural applications.

• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.126-137
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• 2011

Although Sumunmulbangdui wetland at the Halla Mountain in Jeju Island, a kind of montane wetlands, has been considered to bear high biodiversity, no study has been reported on the bacterial diversity. In this study, soil and water samples were collected from the wetland in order to isolate novel bacterial species. Bacterial strains belonging to the phyla Bacteroidetes, Firmicutes, and Actinobacteria were isolated after spreading soil and water samples onto solid agar media. The 16S rRNA gene sequences of the strains assigned to the three phyla were compared to those of type strains of the species in the phyla. The strains that showed less than 98.7% 16S rRNA gene sequence similarity to the validly published species were considered to be novel species candidates. A total of 32 strains were regarded as novel species candidates in the phyla Bacteroidetes, Firmicutes, and Actinobacteria. Diversity of novel species candidates was very low; the candidates were confined to only few genera. In the Bacteroidetes, 13 novel candidate species were affiliated with the genera Mucilaginibacter, Sphingobacterium, Pedobacter, Flavobacterium, and Chryseobacterium. A total of 13 novel candidate species that assigned to the genera Paenibacillus Lysinibacillus, and Bacillus were identified in the phylum Firmicutes. Only two candidate species that belonged to the genera Mycobacterium and Nocardia were excavated in the Actinobacteria. Cultural, physiological, and chemotaxonomic characteristics have been determined for the novel species candidates, and the characteristics are described in this study.

• Journal of Preventive Medicine and Public Health
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• v.22 no.2 s.26
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• pp.290-301
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• 1989

This is preliminary report on anthrax epidemic occurred in an island with about 100 residents. Since 1982 there had been sudden deaths among all kinds of domestic animals including cattle, dogs, ducks, chicken and goat but only a few among cats in an isolated island about three hours distance away by ferry boat from Mokpo city. From 1986 through 1988 nine human deaths and four patients occurred, which made the government intervene for investigation on June 25 1988. The epidemiological investigation consisted of interview survey and medical examination, medical record analysis, laboratory work to isolate the pathogens under the direction of hypothesis derived from the study and further confirmation of the pathogens by international institute. The summarized results are as followings: 1. According to the interview survey there were many deaths among domestic animals usually in cold and dry season such as January through March and September through November; 36 heads of cattle leaving one head, more than 40 hogs(all), hundreds of chicken leaving few alive, goats that had taken home from mountain and two or three cats out of around 40 had sudden deaths from 1982 till 1985, when the residents stopped to purchase and take them into the island anymore. Also there were eleven persons who had experienced the similar syndrome complex to those of admitted and expired patients and four of them revealed typical chest X-ray findings; from one of these four patients(Rho) B. anthracis is isolated. 2. Medical record on patients who had been admitted, showed common characteristics of the disease course. On admission they had either gastrointestinal or upper respiratory infection symptoms which invariably progressed to septicemic nature with pulmonary interstitial infiltration and mediastinal widening/bulging, and then to deadly acute respiratory distress syndrome. At the end stage chest X-ray revealed multiple bullous emphysema. One of another characteristics was oral ulceration with bleeding occurred in about 50% of the patients. Laboratory test results in common were leukocytosis with left shift and abnormal liver and kidney functions, particularly at the later stage of the illness. 3. Epidemiological characteristics was striking in that both mortality and incidence rates were high: the mortality rate was 8.7% average, male being three times higher than females but there was no distictive clustering by age group. The incidence rate for both sexes was 28.2% and there was no sex difference although a tendency of higher incidence among older ages was noticed. The highest mortality and incidence were observed in Won village where the first death of animal occurred and with the highest frequency among three villages of the island. 4. Among twelve bacilli species isolated from various specimens, two strains, one from patient and the other from soil where the recently died cow is hurried, were confirmed as B. anthracis by Pasteur Institute and CDC of USA(strain from soil). CDC reported that the strain did not produce capsule in bicarbonate media but reacted with the bacteriophage and one of five sera taken from the patients. Mode of transmission as well as incubation period of the agent has not been established yet, which needs further investigation in relation to the antigenic structure of the variant when it is confirmed.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.3
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• pp.177-183
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• 2004

The discharge of waste nutrient solution from greenhouse to natural ecosystem leads to the accumulation of excess nutrients that results in contamination or eutrophication. There is a need to recycle the waste nutrient solution in order to prevent the environmental hazards. The amount and kind of nutrients in waste nutrient solution might be enough to grow photosynthetic microorganisms. Hence in the present study, we examined the growth and mass cultivation of cyanobacteria in the waste nutrient solution with an objective of removing N and P and concomitantly, its mass cultivation. Four photosynthetic filamentous cyanobacteria (Anabaena HA101, HA701 and Nostoc HN601, HN701) isolated from composts and soils of the Chungnam province were used as culture strains. Among the isolates, Nostoc HN601 performed faster growth rate and higher N and P uptake in the BG-II ($NO_3{^-}$) medium when compared to those of other cyanobacterial strains. Finally, the selected isolate was tested under optimum conditions (airflow at the rate of $1L\;min^{-1}$. in 15 L reactor, initial pH 8) in waste nutrient solution from tomato hydroponic in green house condition. Results showed to remove 100% phosphate from the waste nutrient solution in the tomato hydroponics recorded over a period of 7 days. The growth rate of Nostoc HN601 was $16mg\;Chl-a\;L^{-1}$ in the waste nutrient solution from tomato hydroponics with optimum condition, whereas growth rate of Nostoc HN601 was only $9.8mg\;Chl-a\;L^{-1}$ in BG-11 media. Nitrogen fixing capacity of Nostoc HN601 was $20.9nmol\;C_2H_4\;mg^{-1}\;Chl-a\;h^{-1}$ in N-free BG-11. The total nitrogen and total phosphate concentration of Nostoc HN601 were 63.3 mg N gram dry weight $(GDW)^{-1}$ and $19.1mg\;P\;GDW^{-1}$ respectively. Collectively, cyanobacterial mass production using waste nutrient solution under green house condition might be suitable for recycling and cleaning of waste nutrient solution from hydroponic culture system. Biomass of cyanobacteria, cultivated in waste nutrient solution, could be used as biofertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.38-44
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• 2005

In addition to the variation in nitrate accumulation of vegetables due to environmental conditions, there is also a distinct genetic variation. The variation of nitrate accumulation in some cultivars of lettuce and spinach commonly cultivated in Korea was investigated. Ten cultivars for both lettuce and spinach were grown in plastic containers filled with a 1:1 mixture of perlite and vermiculite with application of Hoagland No. 2 nutrient solution of high nitrate content (17.3 mM N) in a greenhouse condition. Plants were harvested four weeks after transplanting four-leaf stage seedlings. Plant growth was measured by fresh and dry matter of shoot, and contents of nitrate and other inorganic ions and organic solutes including sugar, amino acids and organic acids were measured. Large and significant genotypical variations in the nitrate content of the plants were found for both lettuce and spinach, and high negative correlations between nitrate content and fresh or dry weight were found in lettuce and spinach. Variation in nitrate accumulation of lettuce and spinach cultivars was not directly related to the differences in contents of organic and inorganic solutes, and this result indicates that photosynthesis and osmotic regulation are not directly related with the nitrate accumulation. Considering the correlations between nitrate content and plant growth of this study, it can be simply suggested that different cultivars of lettuce and spinach have their own inherited growth and physiological characteristics and also optimum nitrogen level required for the growth. Therefore when available nitrogen in root media is higher than the optimum level required for the inherited growth potential, some of the excess nitrate supplied can be accumulated in plants.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.820-825
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• 2007

Earthworm casting was the natural fertilizer that contained high concentrations of nutrients such as nitrogen, phosphate and potassium and of over $10^8$ CFU/ml of microorganisms. Greater than 80% of feed was excreted through the fermentation by the intestinal enzyme, after worm had eaten feeds such as fallen leaves and rotten roots under the ground. Also, the soil structure of casting was known to be very efficient in the aspects of the porosity, the water permeability, and deodorizing activities. In this research, the biofilter packed with a biomedia made of casting and waste polyurethane foam, a binder, which helped to improve the durability and perpetuity of casting, was investigated to degrade malodorous hydrogen sulfide gas. The biomedia had no need of extra supply of nutrients and of microbial inoculations. On the beginning of the operations, it showed 100% removal of hydrogen sulfide gas without lag phase. At SV of 50 $h^{-1}$, hydrogen sulfide gas from the outlet of the biofilter was not detected, when inlet concentration increased to 450 ppmv. After that, removal efficiency decreased as increasing inlet hydrogen sulfide concentration. Hydrogen sulfide removal was maintained at almost 93% until inlet concentration was increased up to 950 ppmv, at which the elimination capacity of $H_2S$ was 61.2 g $S{\cdot}m^{-3}{\cdot}h^{-1}$. Maximum elimination capacity guaranteing 90% removal was 61.2, 65.9, 84.7, 89.4 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV ranging from 50 $h^{-1}$ to 300 $h^{-1}$, but was 59.3 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV of 400 $h^{-1}$. The results calculated from Michaelis-Menten equation revealed that $V_m$ increased from 66.04, 88.96, 117.35, 224.15, to 227.54 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ with increasing space velocity in the range of 50 $h^{-1}$ to 400 $h^{-1}$. However, saturation constant$(K_s)$ decreased from 79.97 ppmv to 64.95 and 65.37 ppmv, and then increased to 127.72 and 157.43 ppmv.

• Journal of Soil and Groundwater Environment
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• v.13 no.4
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• pp.8-21
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• 2008

A series of three-dimensional numerical simulations using a hydrodynamic dispersion numerical model is performed to analyze quantitatively impacts of layered heterogeneity of geologic media and groundwater pumping schemes on groundwater flow and salt transport in coastal aquifer systems. A two-layer heterogeneous coastal aquifer system composed of a lower sand layer (aquifer) and an upper clay layer (aquitard) and a corresponding single-layer homogeneous coastal aquifer system composed of an equivalent lumped material are simulated to evaluate impacts of layered heterogeneity on seawater intrusion. In addition, a continuous groundwater pumping scheme and two different periodical groundwater pumping schemes, which withdraw the same amount of groundwater during the total simulation time, are applied to the above two coastal aquifer systems to evaluate impacts of groundwater pumping schemes on seawater intrusion. The results of the numerical simulations show that the periodical groundwater pumping schemes have more significant adverse influences on groundwater flow and salt transport not only in the lower sand layer but also in the upper clay layer, and groundwater salinization becomes more intensified spatially and temporally as the pumping intensity is higher under the periodical groundwater pumping schemes. These imply that the continuous groundwater pumping scheme may be more suitable to minimize groundwater salinization due to seawater intrusion. The results of the numerical simulations also show that groundwater salinization in the upper clay layer occurs significantly different from that in the lower sand layer under the periodical groundwater pumping schemes. Such differences in groundwater salinization between the two adjacent layers may result from layered heterogeneity of the layered coastal aquifer system.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.329-339
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• 1996

This study is to investigate the effect of mycorrhizal development, growth, nutrient absorption of P. thunbergii seedlings inoculated with Pisolithus tinctorius(Pt. KJ-1) in relation to toxic materials in soil. The concentrations on copper solution applied to the soils were 0, 40, 120, 260, 430ppm. The results are summarized as follows : 1. The germination of P. thunbergii with Pt. increased greater than without ectomycorrhizal fungi. Mycorrhizal development showed a significant decreasing trend at high concentration, and tolerant Cu test with Pt. in agar plate media showed a decreasing trend at a high level. 2. P. thunbergii seedlings inoculated with Pt. showed that the shoot length was significantly promoted at 40, 120ppm copper levels, and that of noninoculated seedlings had the lowest effect in 430ppm copper level. 3. The outer shape of ectomycorrhizal root tips after inoculating Pt. on P. thunbergii seedlings appeared as a monopodial type, a fern-like type, and a cluster-like type at 0ppm, 40ppm levels, but only monopodial type came out at 260ppm, 430ppm copper levels. 4. Root length, no. of juvenile leaves, total length of juvenile leaves, total dry weight, no. of needles and total length of needles of P. thunbergii with Pt. increased greater than those of noninoculated seedling. Growth response of P. thunbergii seedling inoculated with Pt. increased significantly at 40ppm, 120ppm Cu levels. 5. As a result of analysis of growth medium, pH, Na, CEC increased at higher Cu level, and total nitrogen, organic matters, available phosphorous, K, Ca and Mg decreased at 40ppm, 120ppm Cu levels. As a result of an analysis about a copper within soils, it appeared having high Cu-concentration at 0ppm level of an inoculated Pt. and high Cu-concentration in noninoculated Pt. than in inoculated Pt. at higher level. 6. As a result of an analysis of shoot, N, P, and K-concentration were higher in noninoculated seedlings than in inoculated seedlings, and Cu-concentration was higher in inoculated seedlings than in noninoculated seedlings. The analysis of root resulted in a high N-concentration at 40ppm, 120ppm levels, in a high P-concentration in inoculated seedlings and in a high Cu-concentration in noninoculated seedlings. Cu-concentration was significantly higher at root than at shoot.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.19-26
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• 2000

In order to select potent bioactive isolates, 70 Fusarium isolates obtained from soil and 21 plant species were screened by antifungal, insecticidal, herbicidal, and duckweed bioassays after culturing in potato dextrose broth and rice solid media. Eight (11.4%) of the 70 liquid broth cultures showed disease-controlling activities more than 80% against at least one of the 6 plant diseases tested. Fusarium sp. FO-68 isolate exhibited the most potent antifungal activity; it controlled rice blast, wheat leaf rust, and barley powdery mildew with control values more than 95%. Out of 70 solid cultures, 21 (30.0%) controlled at least one plant disease more than 80% and F. equiseti FO-68 isolate showed disease-controlling activities more than 95% against 3 plant diseases such as rice blast, tomato late blight, and wheat leaf rust. As for tile insecticidal activities, 2 liquid and 1 solid cultures showed potent insecticidal activities against pest insects more than 80%, Liquid cultures of F. oxysporum FO-61 and Fusarium sp. FO-80 isolates exhibited insecticidal activities more than 80% against green peach aphid and diamondback moth, respectively. The solid culture of Fusarium sp. FO-510 isolate had 80% insecticidal activity against green peach aphid. However, none of liquid and solid cultures of the 70 Fusarium isolates showed potent herbicidal activities against 10 upland weeds. As the results of duckweed assay, 3 liquid cultures showed 70% growth inhibitory activity at concentrations less than 1.25% of culture supernatants and 9 solid cultures had a potent inhibitory activity against duckweed growth. On the other hand, there was a significant correlation between antifungal activities and herbicidal activities against duckweed of both liquid and solid cultures of tile 70 Fusarium isolates.