• Clean Technology
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• v.19 no.4
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• pp.370-378
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• 2013

This review has shown the capability of MOFs and ZIFs materials to adsorb $CO_2$ under typical PSA temperatures and pressures. The usual operating conditions are adsorption temperatures of $15{\sim}40^{\circ}C$ and adsorption pressures of 4~6 bar based on numerous PSA processes which are widely employed in gases industry for adsorptive separation of $CO_2$. The extent of $CO_2$ adsorption on the microporous materials depends on the metal species and organic linkers existing in the frameworks. The pore size and the surface area, and the process variables are the key parameters to be associated with the efficiency of the adsorbents, particularly adsorption pressures if other variables are comparable each other. The MOFs and ZIFs materials require high pressures greater than 15 bar to yield significant $CO_2$ uptakes. They possess a $CO_2$ adsorption capacity which is very similar to or less than that of conventional benchmark adsorbents such as zeolites and activated carbons. Consequently, those materials have been much less cost-effective for adsorptive $CO_2$ separation to date because of very high production price and the absence of commercially-proven PSA processes using such new adsorbents.

• The Korean Journal of Mycology
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• v.42 no.3
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• pp.225-230
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• 2014

Sclerotinia sclerotiorum, a plant pathogenic fungus, can cause serious yield and quality losses in the winter lettuce field. For biological control of S. sclerotiorum, soil-born microorganisms that inhibit the mycelia growth of S. sclerotiorum and Fusarium oxysporum were isolated from diseased soil. Among the isolates, bacterial isolate, GG95, which was identified as Bacillus subtilis according to the morphological, physiological characteristics and by 16S rRNA similarity, showed the highest level of inhibitory activity. The growth conditions for B. subtilis GG95 were optimized in TSB media (pH 7) by culturing at $28^{\circ}C$ for 24 hrs. Maltose or fructose and peptone were selected as the best carbon and nitrogen sources, respectively. Greenhouse experiment was performed to test effectiveness of B. subtilis GG95 in the control sclerotinia rot. Drench application ($1{\times}10^8cfu/mL$, 3 times) of the bacterial culture broth to lettuce showed an effectiveness value of 88%, suggesting that B. subtilis GG95 would be a promising biocontrol agent for control of sclerotinia rot.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.15-15
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• 2014

Fusarium graminearum (teleomorph Gibberella zeae) is an important plant pathogen that causes head blight of major cereal crops such as wheat, barley, and rice, as well as causing ear and stalk rot on maize worldwide. Plant diseases caused by this fungus lead to severe yield losses and accumulation of harmful mycotoxins in infected cereals [1]. Fungi utilize spore production as a mean to rapidly avoid unfavorable environmental conditions and to amplify their population. Spores are produced sexually and asexually and their production is precisely controlled. Upstream developmental activators consist of fluffy genes have been known to orchestrate early induction of condiogenesis in a model filamentous fungus Aspergillus nidulans. To understand the molecular mechanisms underlying conidiogenesis in F. graminearum, we characterized functions of the F. graminearum fluffy gene homologs [2]. We found that FlbD is conserved regulatory function for conidiogenesis in both A. nidulans and F. graminearum among five fluffy gene homologs. flbD deletion abolished conidia and perithecia production, suggesting that FlbD have global roles in hyphal differentiation processes in F. graminearum. We further identified and functionally characterized the ortholog of AbaA, which is involved in differentiation from vegetative hyphae to conidia and known to be absent in F. graminearum [3]. Deletion of abaA did not affect vegetative growth, sexual development, or virulence, but conidium production was completely abolished and thin hyphae grew from abnormally shaped phialides in abaA deletion mutants. Overexpression of abaA resulted in pleiotropic defects such as impaired sexual and asexual development, retarded conidium germination, and reduced trichothecene production. AbaA localized to the nuclei of phialides and terminal cells of mature conidia. Successful interspecies complementation using A. nidulans AbaA and the conserved AbaA-WetA pathway demonstrated that the molecular mechanisms responsible for AbaA activity are conserved in F. graminearum as they are in A. nidulans. F. graminearum ortholog of Aspergillus nidulans wetA has been shown to be involved in conidiogenesis and conidium maturation [4]. Deletion of F. graminearum wetA did not alter mycelial growth, sexual development, or virulence, but the wetA deletion mutants produced longer conidia with fewer septa, and the conidia were sensitive to acute stresses, such as oxidative stress and heat stress. Furthermore, the survival rate of aged conidia from the F. graminearum wetA deletion mutants was reduced. The wetA deletion resulted in vigorous generation of single-celled conidia through autophagy-dependent microcycle conidiation, indicating that WetA functions to maintain conidia dormancy by suppressing microcycle conidiation in F. graminearum. In A. nidulans, FlbB physically interacts with FlbD and FlbE, and the resulting FlbB/FlbE and FlbB/FlbD complexes induce the expression of flbD and brlA, respectively. BrlA is an activator of the AbaA-WetA pathway. AbaA and WetA are required for phialide formation and conidia maturation, respectively [5]. In F. graminearum, the AbaA-WetA pathway is similar to that of A. nidulans, except a brlA ortholog does not exist. Amongst the fluffy genes, only fgflbD has a conserved role for regulation of the AbaA-WetA pathway.

• Journal of Life Science
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• v.23 no.7
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• pp.933-940
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• 2013

The aim of this work was to determine the chemical composition of essential oil from aerial partsof Mentha arvensis L. f. piperascens (MAO) and to evaluate the effect of its fragrant chemicals on electroencephalographic (EEG) activity of human brain. The MAO was obtained by supercritical $CO_2$ extraction. The maximum yield was 2.38% at conditions of $70^{\circ}C$ and 200 bar. There were 32 volatile chemicals with 6 alcohols (67.11%), 13 hydrocarbons (17.05%), 9 esters (11.50%), 2 ketones (7.16%), 1 oxide (2.77%), and 1 aldehyde (0.56%). The major components were (Z,Z,Z)-9,12,15-octadecatrien-1-ol (50.06%), 2-hydroxy-4-methoxyacetophenone (7.50%), and 3,4-dihydro-8-hydroxy-3-methyl-1H-2-benzopyran-1-one (6.60%). Results of the EEG study showed that inhalation of MAO significantly changed the EEG power spectrum values of relative gamma, relative fast alpha, and spectral edge frequency 90%. During the inhalation of MAO, the value of relative fast alpha was significantly increased (p<0.05). On the other hand, the values of gamma and the spectral edge frequency 90% were significantly decreased (p<0.05). The present study suggests that fragrant chemicals of essential oil of M. arvensis reduce the level of mental stress and that they could be used in the treatment of psychophysiological disorders.

• Food Science of Animal Resources
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• v.33 no.2
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• pp.162-169
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• 2013

We determined the optimum pretreatment conditions such as pH and time for swelling duck feet and investigated the effects of the extracting method, such as water bath (WB), pressure cooker (PC), and microwave oven (MO), on quality characteristics of the duck feet gelatin for improving utilization of duck feet as a novel source of gelatin. The soaking solution of pH 1 among pH 1-14 with unit intervals was selected due to the highest yield. The quality characteristics of the gelatin tested were color, pH, gel strength, viscosity, and melting point. For the extracted gelatin with different methods, the CIE $L^*$, $a^*$ and $b^*$ values were in the following order: MO>PC>WB (p<0.05), WB>PC>MO (p<0.05) and PC>MO>WB (p<0.05), respectively. The gelatin extracted using WB showed the highest pH and that extracted using MO showed the lowest pH (p<0.05). The gel strength, viscosity, and melting point were the highest for MO (p<0.05). The gel strength and melting point were the lowest for PC (p<0.05). No significant difference was found in viscosity between the gelatins extracted using WB and PC (p>0.05). The quality characteristic of duck feet gelatin was affected by extracting methods, and MO extraction can be one of the effective methods for duck feet gelatin.

• Korean Journal of Medicinal Crop Science
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• v.23 no.3
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• pp.198-206
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• 2015

This study was conducted to investigate the effects of sowing density, number of seeds sown per hole, and thinning treatment on growth characteristics and disease occurrence in Panax ginseng under direct sowing cultivation in a blue plastic greenhouse. Seedling were grown from 2 or 3 seeds sown, and the healthiest was only retained, while the rest were thinned out at the foliation stage. $NO_3$-N, $P_2O_5$, and organic matter content differed significantly between growth conditions in the plastic greenhouse and in conventional shade in the soil. Disease also tended to be higher in the conventional shade than in the plastic greenhouse. Plant height and stem length showed an increasing trend with increasing sowing density and number of seeds sown per hole. However, these measures noticeably decreased when thinning treatment was conducted. Growth of the subterranean part of ginseng was not markedly influenced by sowing density, the number of seeds sown per hole, or thinning treatment. Root weight, which is an important factor in yield, was significantly affected by the number of seeds sown and thinning treatment. Interestingly, root weight tended to be higher in the thinning treatment plot than the untreated control plot. Damping-off and root rot increased noticeably as the number of seeds sown increased. Disease also tended to be substantially higher in the thinning treatment plot than the untreated control. However, physiological disorder of the plants did not vary with sowing density, the number of seeds sown, or thinning treatment.

• Applied Biological Chemistry
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• v.42 no.1
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• pp.49-57
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• 1999

Enzymatic hydrolysis with tuna pyloric caeca crude enzyme(TPCCE) was performed to recover a protein hydrolysate from hoki frame, fish processing by-product. Optimum hydrolytic conditions were pH 10.0, temperature $50^{\circ}C$, and incubation time 12 hrs, and then the degree of hydrolysis was about 60%. The yield of the hydrolysate from hoki frame by enzymatic hydrolysis was approximately 77% on a dry weight basis. The prepared protein hydrolysates were also fractionated through a series of 30, 10, 5 and 1 kDa molecular weight cut-off (MWCO) membranes in order to investigate the effect of their functionalities according to the difference of their molecular size. As the result of studying functionalities of the hydrolysates, 1 K hydrolysate showed the highest solubility over all pHs, and 30 and 10 K hydrolysate showed more excellent emulsifying property and whippability than the other hydrolysates.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.179-186
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• 1998

Dextransucrase hyper-producing Leuconostoc mesenteroides B-512FMCM and dextransucrase constitutive mutants B-742CB and B-1355C catalyzed the transfer of glucose from sucrose to other carbohydrates which were present or were added to the reaction digests. When the acceptor was a maltose, gentiobiose, lactose or raffinose, there was produced a series of oligosaccharide acceptor products or single product based on the kinds of enzymes and reaction conditions. To obtain the quantitative information about the yield and the distribution of acceptor products and dextran two experimental parameters were studied: a) the ratio of acceptor to sucrose and b) the amount of enzyme at constant carbohydrate concentration (100 mM). As the amount of enzyme increased, the synthesis of acceptor products (of maltose or gentiobiose) increased, and the formation of dextran decreased. As the ratio of acceptor to sucrose increased, the amount of dextran and the number of acceptor-products decreased and the amount of acceptor-products increased. When maltose or gentiobiose was an acceptor, the glucose from sucrose was transferred to the C-6 hydroxyl group of the nonreducing-end glucose residue of accepters to give a homologous series of isomaltosyl dextrins. In case of lactose or raffinose, there was produced only one acceptor product from B-512FMCM dextransucrase reaction. In the lactose acceptor reaction, the glucose from sucrose was transferred to the C-2 hydroxyl of the reducing end glucose residue of lactose. To get a series of oligosaccharides from lactose or raffinose acceptor reaction we used B-742CB dextransucrase or B-1355C alternansucrase with 500 mM sucrose in reaction digest.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.499-510
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• 2013

Among 25 isolates, Aspergillus fumigatus ASH (JX006238) was identified as a potent producer of homocysteine ${\gamma}$-lyase. The nutritional requirements to maximize the enzyme yield were optimized under submerged (SF) and solid-state fermentation (SSF) conditions, resulting in a 5.2- and 2.3-fold increase, respectively, after the last purification step. The enzyme exhibited a single homogenous band of 50 kDa on SDS-PAGE, along with an optimum pH of 7.8 and pH stability range of 6.5 to 7.8. It also showed a pI of 5.0, as detected by pH precipitation with no glycosyl residues. The highest enzyme activity was obtained at $37-40^{\circ}C$, with a $T_m$ value of $70.1^{\circ}C$. The enzyme showed clear catalytic and thermal stability below $40^{\circ}C$, with $T_{1/2}$ values of 18.1, 9.9, 5.9, 3.3, and 1.9 h at $30^{\circ}C$, $35^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, and $60^{\circ}C$, respectively. Additionally, the enzyme $K_r$ values were 0.002, 0.054, 0.097, 0.184, and 0.341 $S^{-1}$ at $30^{\circ}C$, $35^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, and $60^{\circ}C$, respectively. The enzyme displayed a strong affinity to homocysteine, followed by methionine and cysteine when compared with non-S amino acids, confirming its potency against homocysteinuria-related diseases, and as an anti-cardiovascular agent and a specific biosensor for homocysteinuria. The enzyme showed its maximum affinity for homocysteine ($K_m$ 2.46 mM, $K_{cat}\;1.39{\times}10^{-3}\;s^{-1}$), methionine ($K_m$ 4.1 mM, $K_{cat}\;0.97{\times}10^{-3}\;s^{-1}$), and cysteine ($K_m$ 4.9 m M, $K_{cat}\;0.77{\times}10^{-3}\;s^{-1}$). The enzyme was also strongly inhibited by hydroxylamine and DDT, confirming its pyridoxal 5'-phosphate (PLP) identity, yet not inhibited by EDTA. In vivo, using Swiss Albino mice, the enzyme showed no detectable negative effects on platelet aggregation, the RBC number, aspartate aminotransferase, alanine aminotransferase, or creatinine titer when compared with negative controls.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.676-685
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• 2016

This study investigated the conversion of oil products from polystyrene by using dispersed Co and Mo catalyst on reaction time and concentration change for knowledging on characteristics at low temperature (425, 450 and $475^{\circ}C$) pyrolysis and reaction time(20~80 min, 15 min interval) in a batch reactor. It will be showed the conditions for optimum pyrolysis at reaction temperature $450^{\circ}C$ and the reaction time 35min, and the main components of the converted liquid oil were styrene and benzene derivatives by GC/MS. The oil products formed during pyrolysis were classified into gas, gasoline, kero, diesel and heavy oil according to the domestic specification of petroleum products. The pyrolysis conversion rate was showed as Co catalyst > Mo catalyst > Thermal in all reaction time at reaction temperature $450^{\circ}C$. The yields rate of gas, kerosine, diesel were the most hight at Mo Catalyst, gasoline was at thermal and heavy oil was at Co catalyst. The conversion rate and yields of the pyrolysis products were the most height when Co catalyst ratio was 100%.