• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.234-241
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• 2007

Biological amendments consisting of suspensions of selected microorganisms are often used in conjunction with various organic materials for amending soils to improve soil quality and plant growth. The effects of the biological amendment on chemical and biological properties of soil were investigated for a biological amendmentalone and when combined with different organic materials includingmunicipal compost (MC), poultry litter (PL), and cover crops (red clover (RC) and spring oats). A liquid preparation of a biological amendment called Effective Microorganisms was sprayed on the tested plots three times over a two-year period. Effective Microorganisms alone did not influence pH, K, or organic matter content in soil. However, increases in P in PL-treated soils in fall of both years andCa in MC-treated soil in fall 2001, and decreases in Ca, Mg, and cation exchange capacity (CEC) in RC-planted soil were associated with EM. Increased dehydrogenase(DH) activitiesassociated with Effective Microorganismswere only detected in July (P=0.0222) and October (P=0.0834) for RC-planted soils in the first year. Fluorescein diacetate (FDA) hydrolysisappeared to be enhanced by Effective Microorganisms in soils untreated or treated with MC and oatsbut only sporadically during the sampling period. FDA hydrolysis in both PL- and RC-treated soils as well as DH activity in PL-treated soils decreased with Effective Microorganisms treatment. Effective Microorganisms did not influence substrate utilization patterns expressed by the BIOLOG assay. We conclude that Effective Microorganisms effects on soil chemical and biological properties varied depending on the added organic materials. Effective Microorganisms periodically increased soil DH activity and FDA hydrolysis with RC and with MC plus oats, respectively.

• Mycobiology
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• v.29 no.3
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• pp.160-163
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• 2001

Sikhae is a Korean traditional beverage of saccharified rice. Its factory waste(SFW) is usually thrown away instead of being used. We developed a cheap substrate of SFW for use in liquid spawn that is known for its higher fruit body yields than grain spawn in sawdust cultivation. Mycelia of Lentinula edodes ASI 3046, which is regarded as the most suitable strain for sawdust cultivation, were cultured on six kinds of previous known media and SFW. As the seven kinds of media were applied, a Sikhae Factory Waste(SFW) was most excellent in growth. The dried mycelial weight in SFW was almost four times as much as that in the other media. In the flask culture, optimum culture conditions for the mycelial growth were obtained after 13 days of cultivation at media volume of 100 ml, 100 rpm, initial pH 4.5, and $25^{\circ}C$. The best mycelial growth was observed when $MgSO_4{\cdot}7H_2O$ and D-sucrose were added as a supplement in SFW. SWM must be a remarkable medium for L. edodes because of its simple preparation and low cost.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1359-1366
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• 2010

A search of the Streptomyces avermitilis genome reveals that its closest homologs are several O-methyltransferases. Among them, one gene (viz., saomt5) was cloned into the pET-15b expression vector by polymerase chain reaction using sequence-specific oligonucleotide primers. Biochemical characterization with the recombinant protein showed that SaOMT5 was S-adenosyl-L-methionine-dependent Omethyltransferase. Several compounds were tested as substrates of SaOMT5. As a result, SaOMT5 catalyzed O-methylation of flavonoids such as 6,7-dihydroxyflavone, 2',3'-dihydroxyflavone, 3',4'-dihydroxyflavone, quercetin, and 7,8-dihydroxyflavone, and phenolic compounds such as caffeic acid and caffeoyl Co-A. These reaction products were analyzed by TLC, HPLC, LC/MS, and NMR spectroscopy. In addition, SaOMT5 could convert phenolic compounds containing ortho-dihydroxy groups into O-methylated compounds, and 6,7-dihydroxyflavone was known to be the best substrate. SaOMT5 converted 6,7-dihydroxyflavone into 6-hydroxy-7-methoxyflavone and 7-hydroxy-6-methoxyflavone, and caffeic acid into ferulic acid and isoferulic acid, respectively. Moreover, SaOMT5 turned out to be a $Mg^{2+}$-dependent OMT, and the effect of $Mg^{2+}$ ion on its activity was five times greater than those of $Ca^{2+}$, $Fe^{2+}$, and $Cu^{2+}$ ions, EDTA, and metal-free medium.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.95-105
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• 2016

This study was conducted to evaluate the effects of nitrate-rich plants extracts on the in vitro rumen fermentation characteristics and rumen methane production. The extracts of nitrate-rich plants, as potato, carrot, chinese cabbage, lettuce and spinach were used in this study. The ruminal fluid was collected from a cannulated Hanwoo cow fed concentrate and timothy in the ratio of 6 to 4. The 20mL of mixture, comparing McDougall's buffer and rumen fluid in the ratio 2 to 1, was dispensed anaerobically 50mL serum bottles containing 0.3g of timothy substrate and extracts of nitrogen-rich plants. The serum bottles were incubated 39℃ for 9, 12, 24, 48 hours. The pH value was decreased by increased incubation times and normal range to 6.31 to 6.96. The dry matter digestibility was significantly(p<0.05) lower in chinese cabbage than in control at 9h incubation time. Ammonia concentration was significantly(p<0.05) lower in potato, chinese cabbage, lettuce than in control and the rumen microbial growth rate was significantly(p<0.05) higher in carrot than in control at 24h incubation time. The concentrations of acetate and propionate was significantly(p<0.05) lower in treatment than in control. The concentration of butyrate was showed a different pattern depending on treatments. Total gas emissions was significantly(p<0.05) lower in chinese cabbage, lettuce, spinach than in control at 12h, 24h incubation time. Methane production was significantly(p<0.05) lower in potato, chinese cabbage, spinach than in control, carbon dioxide production was significantly(p<0.05) lower in treatment than in control. In conclusion, supplementation of the nitrate-rich plant extracts in ruminal fermentation in vitro resulted in decreasing the methane production without adversely affecting the fermentation characteristics. Particularly the chinese cabbage extract was regard as a potential candidate for reducing the methane emission in ruminants.

• Proceedings of the Korean Vacuum Society Conference
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• 1996.06a
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• pp.40-41
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• 1996

Nitridation technique has been receiving much attention for the formation of a thin nitrided buffer layer on which high quality nitride films can be formedl. Particularly, gallium nitride (GaN) has been considered as a promising material for blue-and ultraviolet-emitting devices. It can also be used for in situ formed and stable passivation layers for selective growth of $GaAs_2$. In this work, formation of a thin nitrided layer is investigated. Nitrogen electron cyclotron resonance(ECR)-plasma is employed for the formation of thin nitrided layer. The plasma source used in this work is a compact ECR plasma gun3 which is specifically designed to enhance control, and to provide in-situ monitoring of plasma parameters during plasma-assisted processing. Microwave power of 100-200 W was used to excite the plasma which was emitted from an orifice of 25 rnm in diameter. The substrate were positioned 15 em away from the orifice of plasma source. Prior to nitridation is performed, the surface of n-type (001)GaAs was exposed to hydrogen plasma for 20 min at $300{\;}^{\circ}C$ in order to eliminate a native oxide formed on GaAs surface. Change from ring to streak in RHEED pattern can be obtained through the irradiation of hydrogen plasma, indicating a clean surface. Nitridation was carried out for 5-40 min at $RT-600{\;}^{\circ}C$ in a ECR plasma-assisted molecular beam epitaxy system. Typical chamber pressure was $7.5{\times}lO^{-4}$ Torr during the nitridations at $N_2$ flow rate of 10 seem.(omitted)mitted)

• Microbiology and Biotechnology Letters
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• v.25 no.1
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• pp.89-95
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• 1997

The current processer of the textile wastewater treatment are mostly consisted of a combination of a physico-chemical and a biological treatment. The overall efficiency of these processes is, however, assessed to be fairly low. It is even worse during the summer season when temperature of the wastewater rises above 40$\circ $C. Therefore, a feasible process of the textile wastewater treatment which can work efficiently at higher temperatures was investigated in this work. We used a bench scale reactor consisted of one 4 liter anaerobic and one 8 liter aerobic tank, and the thermophilic symbiotic PVA degraders, Pasteruella hemolytica KMG1 and Pseudomonas sp. KMG6 that had been isolated in our laboratory. In the preliminary flask experiments, we observed that the thermophilic symbiotic PVA degraders could not grow in the wastewater substrate. Then, we isolated the mutant strains by acclimating the KMG1and KMG6 strains to the wastewater medium. The mutant symbionts (KMG1-1 and KMG6-1) were isolated through 6 times successive transfers into the fresh wastewater medium after 5 days culture for each. The mutant strains obtained grew well in the mixed medium composed of 75% wastewater and 25% synthetic medium, and supplemented with 0.5% PVA as a sole carbon source. During the culture for 14 days at pH 7.0 and 40$\CIRC $C, the bacteria assimilated about 89% of the added PVA. The symbionts degraded equally well all the PVA substrates of different molecular weight (nd=500~30000). In contrast to the flask experiments, in the reactor system the mutant strains showed very low levels of the PVA and COD removal rates. However, the new reactor system with an additional aerobic tank attained 82% removal rate of COD, 94% of PVA degradation and 71% of color index under the conditions of 5% inoculm on the tank 2, incubation temperature of 40$\circ $C, dissolved oxygen level of 2~3 mg/l and retention time of 30 hours. This result ensures that the process described above could be an efficient and feasible treatment for the PVA contained textile wastewater at higher temperatures.

• The Korean Journal of Malacology
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• v.25 no.2
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• pp.97-103
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• 2009

It is a research that free floating larva of Ruditapes philippinarum in compliance with infiltration flow of tidal accumulation and bottom-clinging system in high density also, It is a precondition this for the continuous augmentation of Ruditapes philippinarum resources. So in flow field of tidal the free floating larva produced the infiltration water tank that can possibly bottom-clinging and experiment the water tank which uses free floating larva, It evaluates that the acceleration effect of free floating larva by infiltration in objective. As a result, 1) The experiment on free floating larva's bottom sediment grain diameter came to be high recording as bottom-clinging rate at the static water field and even biologically it selects bottom-clinging substrate it will be able to confirm. 2) About occurrence of infiltration flow field is in case of that: the drift of a current 10cm/s, bottom sediment grain 1.21mm infiltration flow 0.3cm/s increase of 3~5 times was confirmed. 3) From free floating larva of Ruditapes philippinarum the choice of bottom sediment grain diameter depends in the biological factor and form the flow field the bottom-clinging acceleration effect was controled over physical stable condition. 4) In case of density of Ruditapes philippinarum free floating larva of sea area, bottom sediment grain diameter, flow condition which are very cleanly in the research that possibly could conjecture the free floating larva's bottom-clinging rate.

• The Korean Journal of Mycology
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• v.28 no.2
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• pp.67-72
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• 2000

The purpose of this study was to investigate the change of water content in mushroom substrate, paddy straw, and the mycelial growth of oyster mushroom by various soaking time. The water content of paddy straw was gradually increased as the soaking time was getting longer. These experiments also showed that the water content in the upper part of paddy straw was less than that of the low part. The mycelial growth was the good between 4 and 12 hours soaking treatment, showing faster growth and higher density in the lower part than the upper part. However we could not found any significant variation among 5 strains of oyster mushroom in the effects of the various soaking times and soaking part. The pH of the lower part substrates had a low pH compared with that of the upper part. When pathogens and mushroom mycelia were co-inoculated on paddy straw under various soaking conditions, the mushroom mycelial growth showed fast and high density according to the increase of the soaking time. The experiment related to water transport reveals that it is not easy to move into upper part, but only soaked part by adding water is available to absorb enough water. Old straw was much better than the straw new this year one for water absorption, mycelial growth and mycelial density.

• Applied Biological Chemistry
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• v.27
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• pp.29-46
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• 1984

To utilize several species of hard wood as raw materials of feed products, fermentation characteristics of cellulosic substrates to single cell protein was investigated, and results were summarized as follows. Among the microorganisms investigated, Tricoderma viride was selected as one of the most cellulolytic. Mixed culture of fungi did not show a synergistic effect on cellulose degradation. When the fungi were cultured at $28^{\circ}C$ for 7 days in a medium containing wheat bran 25 g, cellulose 0.25 g, proteose peptone 0.025 g and tween 800.025 g, cellulotic activities on carboxy methyl cellulose and filter paper reached maximum at 12 hr. The alkali treatment resulted in increased degradation of substrate from 13 to 18% when treated with enzymes for 12h, and reducing sugar formation increased with decreased size of substrates. Glucose was a very good feedback inhibitor of the enzyme from T.viride than that of xylose. When the substrate was rehydrolyzed, hydrolysis rate was 31% to reducing sugars within 12 hr. Quantative anlysis with HPLC showed the ratio of glucose to xylose in sugar syrups as 1.77 to 1. For the purpose of producing cellulosic-single cell protein from the sawdust of mulberry tree, 15 strains of xylose-assimilating yeast were isolated from 42 samples of rotten woods and compost soils and examined for their ability to utilize xylose. Then three strains were selected by their strong xylose-assimilating activities. The cultivative condition, the growth characteristics, and protein and nucleic acid productivities of three strains were investigated. The results obtained were, 1. Wood hydrolysate of mulberry tree was assimilated by 5 strains of CHS-2, CHS-3, ST-40, CHS-12 and CHS-13. 2. The optimum initial pH and temperature for the growth of strain CHS-13 were 4.4 and $30^{\circ}C$. 3. The specific growth rate of strain CHS-13 was $0.23h^{-1}$ and generation time was 3.01 hrs at the optimum condition. 4. CHS-13 strain assimilated 81 % of sugar in wood hydrolysate. 5. CHS-13 strain was identified as Candida guilliermondii var. guilliermondii 6. When the CHS-13 strain was cultured in the wood hydrolysate containing yeast extract, L-protein content was increased with yeast extract concentration. 7. The L-protein and nucleic acid yields from wood hydrolysate were 0.73 mg/ml and $4.92{\times}10^{-2}\;mg/ml$ respectively. 8. An optimal nucleic acid content of CHS-13 strain was observed in the medium containing 0.2% of yeast extract.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.195-200
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• 2011

The growth, yield and quality of Sedum sarmentosum between soil and hydroponic cultivation were compared to produce high-quality shoots in summer season. The plants were collected from four places in Korea and cultivated in a plastic film house with 50% shading. A 1:1:1 mixtures of sand, upland soil and substrate (N-P-K: 330-220-400 $mg{\cdot}L^{-1}$) was used for soil cultivation, and a nutrient film technique (NFT) with Yamazaki-lettuce nutrient solution used for hydroponics. After 30 days of cultivation, plant height ranged from 18.4 to 21.8 cm and showed no significant difference between soil and hydroponic cultivation. Number of shoot, leaf length, leaf width, number of leaf, fresh weight, and dry weight significantly increased in hydroponics compared to those in soil cultivation. Fresh and dry weights in hydroponics were greater in 'Gunsan' and 'Wando' collections than those in other collections. Stem diameter and compression-force significantly increased in soil cultivation rather than hydroponics with significant differences among collections. However there were no significant differences in shoot bitterness and vitamin C content between cultivation methods or among the collections. Most mineral contents except Fe in hydroponics were higher than those in soil cultivation. K, Na, Zn contents in hydroponics were over 2 times higher than those in soil cultivation.