• Journal of Soil and Groundwater Environment
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• 제8권4호
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• pp.45-52
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• 2003

A gas-substrate degrading bacterium, Nocardia SW3, was isolated from the gasoline contaminated aquifer using propane and butane as carbon and energy sources. We have examined the effects of substrate concentration, temperature and pH on the gas substrate degradation as well as MTBE cometabolic degradation. The result for the effect of substrate concentration showed that the maximum degradation rates of propane and butane were 30.6 and 25.4 (n㏖/min/mg protein) at 70 $\mu$㏖, respectively. The optimum temperature and pH for the degradation of gas substrate were $30^{\circ}C$ and 7, respectively. Substrate degradation activity, however, was still active in broad range of pH from 5 to 8 and temperature between $15^{\circ}C$and$35^{\circ}C$. The degradation activity of Nocardia SW3 for the MTBE was similar to the both substrates. The observed maximal transformation yields ($T_y$) were 46.7 and 35.0 (n㏖ MTBE degraded $\mu$㏖ substrate utilized), and the maximal transformation capacities ($T_c$) were 320 and 280 (n㏖MTBE degraded/mg biomass used) for propane and butane oxidizing activity on MTBE, respectively. And also, TBA was detected as by-product of MTBE and it was continuously degraded further.

• Korean Journal of Medicinal Crop Science
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• 제11권5호
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• pp.371-376
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• 2003

To develop an efficient cultivation system to increase the productivity and the high quality of Chrysanthemum boreale M., the effects of pig manure (PM) application on the yield and the effective component were investigated in the pot scale (1/2000a scale). PM applied at the equivalent of six rates (with rate of 0, 2000, 4000, 6000, 8000, and 12000 kg $10a^{-1}$). Maximum plant biomass yield was achieved at 9510 kg $10a^{-1}$ and at 9940 kg $10a^{-1}$ for flower biomass. Nitrogen recovery efficiency was more than 42% for all nitrogen treatments and reached 66.6% at 4000 kg $10a^{-1}$. Proline $(7.4{\sim}9.2\;g\;kg^{-1})$ was the most abundant amino acid in the flower of C. boreale M. and the contents of amino acids increased with increasing PM application rate. Contents of cumambrin A. a sesquiterpene compound known to reduce blood-pressure, decreased with increasing PM application. The highly negative correlation was found ($R^2$ = -0.723, P<0.01) between content of cumambrin A and PM application. However, the amount of cumambrin A in flowers increased as PM rate increased, because of increasing flower yield. In conclusion, PM fertilization increases yields and enhances overall quality.

• KSBB Journal
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• 제11권1호
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• pp.22-29
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• 1996

Immobilized bioprocess was carried out for continuous production of cyclosporin A (CyA) produced intracellularly as a secondary metabolite by a filamentous fungus, Tolypocladium inflatum. Immobilization procedure for entrapping conidiospores of the producer was significantly simplified by use of a modified immobilization technique. A newly-designed immobilized perfusion reactor system (IPRS) showed good process benefits as demonstrated by the role of the high density immobilized cells as an efficient biomass generator, continuously supplying highly active CyA-producing free cells (1.0g/$\ell$/hr) even at very high dilution rate ($0.1hr^{-1}$). IPRS bioprocess was possible since efficient decantor system developed in our laboratory separated the sloughed-off free cells from the immobilized biomass effectively, thus overcoming wash-out phenomenon frequently encountered in continuous free cell cultures. Furthermore the released-free cells remaining in the bulk solution did not appear to cause substrate mass transfer limitation which was often experienced in suspended mycelial fungal cell fermentations. The primary reason for this was that the suspension broth of the IPRS mainly consisted of roundshaped short mycelial fragments and conidiospores, still remaining Newtonian even at high cell density. In parallel with IPRS bioprocess development, other key factors to be considered necessarily for significant increase in CyA productivity would be strain improvement and medium optimization for the immobilized cells.

• Korean Journal of Soil Science and Fertilizer
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• 제46권1호
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• pp.40-48
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• 2013

This study evaluated the close crop recycling method by using the extract from defective onions. The mixture of the diluted extract (1/500) and nutrients was applied seven times on the onion leaves without spilling it onto the field. The yield and quality of the onions produced by this method (recycle) were compared to those grown organically (control) and conventionally (normal). The yield from the recycling field was increased significantly by 9% compared to that of the control field, while it was decreased by 11% compared to the normal field (p < 0.05). This lower yield was explained by the differences of the mulching vinyl and the fertilizers between the treatments which effect the onion growth during the winter. The content of quercetin in the onions from the recycling filed was increased significantly by 34% and 44% compared to those of the control and normal field, respectively (p < 0.05). It seemed that minerals and biologically active substances in the defective onion extract were effective in increasing the onion growth. In terms of soil microbial biomass, arbuscular mycorrhizal fungi was increased significantly in the recycle field by 40.1% and 30.6% compared to those of the control and normal fields, respectively (p < 0.05). On the other hand, microbial stress (cy19:0/18:1w7c) was decreased in the recycle field by 21.0% and 14.1% compared to those of the control and normal fields, respectively.

• Research in Plant Disease
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• 제11권1호
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• pp.66-71
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• 2005

The effect of medium components such as wheat bran, rice bran, oat meal, and soybean meal as basic ingredients and KH2PO4, glucose, and molasses as additives on mass production and anti-potato common scab activ ity of a streptomycete A020645 strain as a biocontrol agent (BCA) candidate was investigated. Of basicingredients, oat meal was the best one for mass poduction and enhancement of anti-potato common scabactivity. The biomass production of the active strain was more enhanced when 0.1-0.01.% glucose or molassesas additive were added into the basic medium. These information may have important implications in applying for effective formulation of BCA.

• Journal of the Korea Organic Resources Recycling Association
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• 제31권1호
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• pp.57-68
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• 2023

In this study, coffee waste was recycled into nitrogen-doped porous carbon fibers as an active material for high-energy EDLC (Electric Double Layer Capacitors). The coffee waste was mixed with polyvinylpyrrolidone and dissolved into dimethylformamide. The mixture was then electrospun to fabricate coffee waste-derived nanofibers (Bare-CWNF), and carbonization process was followed under a nitrogen atmosphere at 900℃. Similar to Bare-CWNF, the as-synthesized carbonized coffee waste-derived nanofibers (Carbonized-CWNF) maintained its fibrous form while preserving the composition of nitrogen. The electrochemical performance was analyzed for carbonized coffee waste (Carbonized-CW)-, carbonized PAN-derived nanofibers (Carbonized-PNF)-, and Carbonized-CWNF-based electrodes in the operating voltage window of -1.0-0.0V, Among the electrodes, Carbonized-CWNF-based electrodes exhibited the highest specific capacitance of 123.8F g^-1 at 1A g^-1 owing to presence of nitrogen and porous structure. As a result, nitrogen-contained porous carbon fibers synthesized from coffee waste showed excellent electrochemical performance as electrodes for high-energy EDLC. The experimental designed in this study successfully demonstrated the recycling of the coffee waste, one of the plant-based biomass that causes the environmental pollution into high-energy materials, also, attaining the ecofriendliness.

• Korean Journal of Soil Science and Fertilizer
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• 제45권1호
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• pp.30-36
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• 2012

The active fraction of soil organic matter, which includes organic debris and light organic fraction, plays a major role in nutrient cycling. In addition, particulate organic matter is a valuable index of labile soil organic matter and can reflect differences in various soil behaviors. Since soil organic matter bound to soil mineral particles has its density lower than soil minerals, we partitioned soil organic matter into debris ($<1.5g\;cm^{-3}$), light fraction ($1.5-2.0g\;cm^{-3}$), and heavy fraction ($>2.0g\;cm^{-3}$), based on high density $ZnCl_{2-}$ sucrose solutions. Generally, partitioned organic bands were clearly separated, demonstrating that the $ZnCl_{2-}$ sucrose solutions are useful for such a density gradient centrifugation. The available gradient ranges from 1.2 to $2.0g\;cm^{-3}$. Although there was not a statistically meaningful difference in organic debris and organomineral fractions among the examined soils, there was a general trend that a higher content of organic debris resulted in a higher proportion of light organomineral fraction. In addition, high clay content was associated with increased fraction of light organomineals. Partitioning of soil organic carbon revealed that carbon content is reduced in the heavy fraction than in the light fraction, reflecting that the light fraction contains more fresh and abundant carbon than the passive resistant fraction. It was also found that carbon contents in the overall organic matter, debris, light fraction, and heavy fractions may differ considerably in response to different farming practices.

• Journal of the Korean Institute of Rural Architecture
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• 제20권1호
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• pp.69-76
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• 2018

This study is to research technical measures for improving energy efficiency in the conservation and reuse of historic buildings focused on the recent research trends and case studies of the west. These measures are broadly classified into three types, the passive measures for saving energy and increasing comfort, the most cost-effective energy saving strategies, and the renewable energy sources. Firstly, the passive measures are divided into the elements and systems. The passive elements are awnings and overhanging eaves, porches, shutters, storm windows and doors, and shade trees. There are also the natural ventilation systems such as the historic transoms, roofs and attics to improve airflow and cross ventilation to either distribute, or exhaust heat. Secondly, the most cost-effective energy efficiency strategies are the interior insulation, airtightness and moisture protection, and the thermal quality improvement of windows. The energy efficiency solutions of modern buildings are the capillary-active interior insulation, the airtightness and moisture protection of interior walls and openings, and the integration of the original historic window into the triple glazing. Beyond the three actions, the additional strategies are the heat recovery ventilation, and the illumination system. Thirdly, there are photovoltaic(PV) and solar thermal energy, wind energy, hydropower, biomass, and geothermal energy in the renewable energy sources. These energy systems work effectively but it is vital to consider its visual effect on the external appearance of the building.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1221-1228
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• 2005

Carbon electrode was applied to a wastewater treatment system as biofilm media. The spatial distribution of heterotrophic bacteria in aerobic wastewater biofilm grown on carbon electrode was investigated by scanning electron microscopy, atomic force microscopy, and biomass measurement. Five volts of electric oxidation and reduction potential were charged to the carbon anode and cathode of the bioelectrochemical system, respectively, but were not charged to electrodes of a conventional system. To correlate the biofilm architecture of bacterial populations with their activity, the bacterial treatment efficiency of organic carbons was measured in the bioelectrochemical system and compared with that in the conventional system. In the SEM image, the biofilm on the anodic medium of the bioelectrochemical system looked intact and active; however, that on the carbon medium of the conventional system appeared to be shrinking or damaging. In the AFM image, the thickness of biofilm formed on the carbon medium was about two times of those on the anodic medium. The bacterial treatment efficiency of organic carbons in the bioelectrochemical system was about 1.5 times higher than that in the conventional system. Some denitrifying bacteria can metabolically oxidize $H_{2}$, coupled to reduction of $NO_{3}^{-}\;to\;N_{2}$. $H_{2}$ was produced from the cathode in the bioelectrochemical system by electrolysis of water but was not so in the conventional system. The denitrification efficiency was less than $22\%$ in the conventional system and more than $77\%$ in the bioelectrochemical system. From these results, we found that the electrochemical coupling reactions between aerobic and anaerobic reactors may be a useful tool for improvement of wastewater treatment and denitrification efficiency, without special manipulations such as bacterial growth condition control, C/N ratio (the ratio of carbon to nitrogen) control, MLSS returning, or biofilm refreshing.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1244-1249
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• 2009

Endophytic fungi are known for the production of valuable metabolites, but information on the gibberellin production capacity of this group is limited. We isolated 9 endophytic fungi from the roots of salt-stressed soybean plants and screened them on waito-c rice, in order to identify plant growth promoting fungal strains. The fungal isolate TK-2-4 gave maximum plant length (20.35 cm) promotion in comparison with wild-type Gibberella fujikuroi (19.5 cm). In a separate experiment, bioassay of TK-2-4 promoted plant length and biomass of soybean cultivar Taegwangkong. The TK-2-4 culture filtrate was analyzed for the presence of gibberellins, and it was found that all physiologically active gibberellins, especially $GA_4$ and $GA_7$, were present in higher amounts ($GA_1$, 0.11 ng/ml; $GA_3$, 2.91 ng/ml; $GA_4$, 3.21 ng/ml; and $GA_7$, 1.4 ng/ml) in conjunction with physiologically inactive $GA_9$ (0.05 ng/ml), $GA_{12}$ (0.23 ng/ ml), $GA_{15}$ (0.42 ng/ml), $GA_{19}$ (0.53 ng/ml), and $GA_{20}$ (0.06 ng/ml). The fungal isolate TK-2-4 was later identified as a new strain of Phoma herbarum, through the phylogenetic analysis of 28S rDNA sequence.