• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1213-1222
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• 2009

The search for diverse plant growth-promoting (PGP) diazotrophic bacteria is gaining momentum as efforts are made to exploit them as biofertilizers for various economically important crops. In the present study, 17 diazotrophic strains belonging to eight different genera isolated from rice paddy fields were screened for multiple PGP traits and evaluated for their inoculation effects on canola and rice plants. All of the strains tested positive for 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity and production of indole 3-acetic acid (IAA) and ammonia ($NH_3$). Additionally, four of the strains were able to solubilize phosphorus (P), five tested positive for zinc (Zn) solubilization and sulfur (S) oxidation, and eight strains produced siderophores. Based on the presence of multiple PGP traits, 10 strains were selected for inoculation studies. Treatment with Herbaspirillum sp. RFNB26 resulted in maximum root length (54.3%), seedling vigor, and dry biomass in canola, whereas Paenibacillus sp. RFNB4 exhibited the lowest activity under gnotobiotic conditions. However, under pot culture conditions, Paenibacillus sp. RFNB4 significantly increased plant height and dry biomass production by 42.3% and 29.5%, respectively. Canola plants and rhizosphere soils inoculated with Bacillus sp. RFNB6 exhibited significantly higher nitrogenase activity. In greenhouse experiments, Serratia sp. RFNB18 increased rice plant height by 35.1%, Xanthomonas sp. RFNB24 enhanced biomass production by 84.6%, and rice rhizosphere soils inoculated with Herbaspirillum sp. RFNB26 exhibited the highest nitrogenase activity. Our findings indicate that most of the selected strains possess multiple PGP properties that significantly improve the growth parameters of the two plants when tested under controlled conditions.

• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.401-418
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• 2000

1. Production of the artificial zeolite from coal ash Coal fly ash is mainly composed of several oxides including $SiO_2$ and $Al_2O_3$ derived from inorganic compounds remained after burning. As minor components, $Fe_2O_3$ and oxides of Mg, Ca, P, Ti (trace) are also contained in the ash. These components are presented as glass form resulting from fusion in the process of the combustion of coal. In other word, coal ash may refer to a kind of aluminosilicate glass that is known to easily change to zeolite-like materials by hydrothermal reaction. Lots of hot seawater is disposing near thermal power plants after cooling turbine generator periodically. Using seawater in the hydrothermal reaction caused to produce low price artificial zeolite by reduction of sodium hydroxide consumption, heating energy and water cost. As coal ash were reacted hydrothermally, peaks of quartz and mullite in the ash were weakened and disappeared, and new Na-Pl peaks were appeared strengthily. Si-O-Si bonding of the bituminous coal ash was changed to Si-O-Al (and $Fe^{3+}$) bonding by the reaction. Therefore the produced Na-Pl type zeolite had high CEC of 276.7 $cmol^+{\cdot}kg^{-1}$ and well developed molecular sieve structure with low concentration of heavy metals. 2. Utilization of the artificial zeolite in agro-environment The artificial zeolite(1g) could remove 123.5 mg of zinc, 164.7 mg copper, 184.4 mg cadmium and 350.6 mg lead in the synthetic wastewater. The removability is higher 2.8 times in zinc, 3.3 times in copper, 4.7 times in cadmium and 4.8 times in lead than natural zeolite and charcoal powder. When the heavy metals were treated at the ratio of 150 $kg{\cdot}ha^{-1}$ to the rice plant, various growth inhibition were observed; brownish discoloration and death of leaf sheath, growth inhibition in culm length, number of panicles and grains, grain ripening and rice yield. But these growth inhibition was greatly alleviated by the application of artificial zeolite, therefore, rice yield increased $1.1{\sim}3.2$ times according to the metal kind. In addition, the concentration of heavy metals in the brown rice also lowered by $27{\sim}75%$. Artificial Granular Zeolites (AGZ) was developed for the purification of wastewater. Canon exchange capacity was 126.8 $cmol^+{\cdot}kg^{-1}$. AGZ had Na-Pl peaks mainly with some minor $C_3S$ peaks in X-ray diffractogram. In addition, AGZs had various pore structure that may be adhere the suspended solid and offer microbiological niche to decompose organic pollutants. AGZ could remove ammonium, orthophosphate and heavy metals simultaneously. Mixing ratio of artificial zeolite in AGZs was related positively with removal efficiency of $NH_4\;^+$ and negatively with that of $PO_4\;^{3-}$. Root growth of rice seedling was inhibited severely in the mine wastewater because of strong acidity and high concentration of heavy metals. As AGZ(1 kg) stayed in the wastewater(100L) for 4days, water quality turned into safely for agricultural usage and rice seedlings grew normally.

• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.76-81
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• 2001

The germination test was used to detect biological changes in irradiated rice and glutenous rice at low doses. Grains were irradiated at below 0.5 kGy, husked and placed on distilled water moistend filter paper in a covered petri-dish. A germination test of 20 grains was carried out at room temperature for 5 days. The shoots and roots of non-irradiated rices grew well in comparison with those of irradiated rices above 0.3 kGy. The roots of rices were more sensitive to irradiation than the shoots, and the growth of roots was significantly decreased with the increasing doses. In glutinous rices, the growth of shoots and roots was retarded by irradiation at 0.2 kGy or more after 3rd days. We concluded that if the shoot or root length is 10 mm or longer within 5 day, the rices and glutinous rices are identified as non-irradiated.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.156-160
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• 2010

This study was performed to provide useful information for kentucky bluegrass management during summer by application of plant growth regulator, Trinexapac-ethyl. Visual quality, shoot density and chlorophyll contents of treatment blocks were significantly different from those of control during summer by application of Trinexapac-ethyl. The turfgrass density of treatment was increased of 4ea/$10\;cm^2$, especially about 5ea/$10\;cm^2$ during the growth retarded period of June and July. Chlorophyll contents index and visual quality of kentucky bluegrass were improved by application of Trinexapac-ethyl during summer, too. In addition, the occurrence of foliage in rainy and high temperature season was less than that of control. However, there was no significant difference in the root length of Kentucky Bluegrass. Meanwhiles, mowing height of kentucky Bluegrass was suppressed by 38% at 2 WAT week after treatment and that there was no significant growth of treatment at 4 WAT. In this experiment, turfgrass quality was significantly better than that of control during July, even though trinexapac-ethyl wasn't applied at all in July. Consequently, periodic treatment of trinexapac- ethyl from spring would be very important to promote the turfgrass visual quality during summer which is unfavorable season on the growth of kentucky bluegrass. And it is possible to reduce mowing times at least 30% for 2 weeks by one application of Trinexapac-ethyl 0.02~0.03 ml/$m^2$ in kentucky bluegrass fairway. Additively, trinexapac- ethyl treatment can be helpful environmentally by cutting down the fertilizers and pesticides in golf course.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1467-1475
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• 2015

The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts on plant growth promotion. This study, based on phytohormonal analyses, aimed at exploring the potential mechanisms by which Enterococcus faecium LKE12 enhances plant growth in oriental melon. A bacterial strain, LKE12, was isolated from soil, and further identified as E. faecium by 16S rDNA sequencing and phylogenetic analysis. The plant growth-promoting ability of an LKE12 bacterial culture was tested in a gibberellin (GA)-deficient rice dwarf mutant (waito-C) and a normal GA biosynthesis rice cultivar (Hwayongbyeo). E. faecium LKE12 significantly improved the length and biomass of rice shoots in both normal and dwarf cultivars through the secretion of an array of gibberellins (GA₁, GA₃, GA₇, GA₈, GA₉, GA₁₂, GA₁₉, GA₂₀, GA₂₄, and GA₅₃), as well as indole-3-acetic acid (IAA). To the best of our knowledge, this is the first study indicating that E. faecium can produce GAs. Increases in shoot and root lengths, plant fresh weight, and chlorophyll content promoted by E. faecium LKE12 and its cell-free extract inoculated in oriental melon plants revealed a favorable interaction of E. faecium LKE12 with plants. Higher plant growth rates and nutrient contents of magnesium, calcium, sodium, iron, manganese, silicon, zinc, and nitrogen were found in cell-free extract-treated plants than in control plants. The results of the current study suggest that E. faecium LKE12 promotes plant growth by producing GAs and IAA; interestingly, the exogenous application of its cell-free culture extract can be a potential strategy to accelerate plant growth.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.239-243
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• 2006

This research compared growth and flowering of potted $Viola{\times}wittrockiana$ 'Majestic GT Scarlet Shadow' in various mixtures of recycled perlite and cellular glass foam (CGF). The crop was cultured in a mat subirrigation system. Numbers of leaves, opened flowers, flower buds, and branches, fresh and dry weights of shoot, leaf area, and total chlorophyll concentration were the greatest in plants grown in the medium of used perlite + granular rockwool+ peatmoss (25:50:25, v/v/v). Plant height and length of the longest root were the highest and longest, respectively, in plants grown in the medium of CGF+peatmoss (25:75, v/v). The medium of CGF+peatmoss (25:75, v/v) was better than the medium of used perlite+peatmoss (25:75, v/v) in plant growth. The medium of CGF + granular rockwool (25:75, v/v) was poorer than the medium of recycled perlite + granular rockwool (25:75, v/v).

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.270-276
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• 1997

This experiment was conducted to develop a practical method to growth in hydroponics conditions. For this purpose, leaf lettuce (Lactuca sativa L., cv. 'Cheongchima') was cultivated under different temperature and light conditions in experimental fields of Sahmyook university from March, 1991 to May, 1996. The visual quality score(VQS), a quantitative parameter to evaluate harvested leaf lettuce quality. The leaf lettuce cultivated at $25^{\circ}C$ solution temperature showed the highest fresh weight pe, plant (59.7g/plant), but lowest visual quality score (5.2), while leaf lettuce cultivated at 15$^{\circ}C$ solution temperature showed lower fresh weight per plant (25.2g/plant) but highest visual quality score (7.2). In general, growth of leaf lettuce was retarded by low solution temperature, but quality was higher than those of other solution temperature. Different day/night temperature of nutrient solutions 20/2$0^{\circ}C$ and 25/2$0^{\circ}C$ was highest in yield, but leaf type was grow longer, and visual quality are inferior to low temperature. Yield was decreased as 10 and 25% at 60 and 80% shading treatment, respectively. Chlorophyll content was decreased by shading. but plant height and root length were increased of leaf lettuce growth with hydroponics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.451-456
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• 1995

To elucidate the intrinsic rheological properties of carboxymethyl chitin (CM-chitin) from the shell of red snow cyab (Chinonecetes japonicus), the configuration and polyelectrolyte behavior of CM-chitin in low concentration solution were investigated. Unperturbed dimensions were ranged from $127{\AA}\;to\;113{\AA}$ as root mean square end-to-end distance$(r_0)$, $52{\AA}$ to $46{\AA}$ as radius of gyration$(S_0)$. The intramolecular expansion tarter(a) was not varied with molecular weight and was 2.1. And effective bond length $(b_0)$ was $14.5{\AA}$. In perturbed condition, Flory constant was $2.35\times10^{21}$. When ionic strength were 0.02 and 1.0, intrinsic viscosity were 1.95dl/g and 1,06 dl/g, respectively. These results suggested that CM-chitin is a polyelectrolyte in aqueous media. At infinite ionic strength, intrinsic viscosity was 0.91dl/g. The intrinsic stiffness of CM-chitin backbone was estimated by evaluating the stiffness parameter (B) as 0.11 and agreed well with the results of k-carrageenan.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.413-423
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• 2013

To elucidate the variation of species composition, biomass and length distribution of flatfishes by the period and region in the Uljin marine ranching area, bottom trawl survey was investigated at the six stations from Feb. 2008 to Dec. 2010. During the survey period, a total 4 families 17 species in the Pleuronectiformes, average 69,158 $ind./km^2$ and 5,625 $kg/km^2$ were identified, in 2008 appeared in 14 species, average 25,798 $ind./km^2$ and 2,333 $kg/km^2$ and in 2009 appeared in 13 species, average 102,360 $ind./km^2$ and 5,634 $kg/km^2$ and in 2010 appeared in 14 species, average 75,704 $ind./km^2$ and 8,632 $kg/km^2$. The individual dominant species, occupying over 10% of total individuals, was Pleuronectes herzensteini (20,811 ind., 30.0%), Hippoglossoides pinetorum (18,666 ind., 26.9%) and Glyptocephalus stelleri (13,499 ind., 19.4%) also the biomass dominant species, occuping over 10% of total biomass, was P. herzensteini (2,207 kg, 39.3%), Pleuronectes yokohamae (857 kg, 15.3%), H. pinetorum (761 kg, 13.5%), Kareius bicoloratus (677 kg, 12.1%). From the cluster and MDS analysis based on Bray-Curtis similarity matrix of fourth root transformed data of species number and individuals in the Uljin marine ranching area from Feb. 2008 to Dec. 2010 was divided into two different groups of the flatfishes community in 2008 and from Jan. to Apr. in 2009 and 2010 (Group A) and the pleuronectiform community in from May to Dec. in 2009 and 2010 (Group B). From the cluster and MDS analysis using the similarity of demersal organisms community among six stations, the Uljin marine ranching area was divided into two different groups of Group 1 (St. 1 and St. 3) and Group 2 (St. 2, St. 4, St. 5 and St. 6).

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.498-505
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• 2010

To evaluate the effectiveness of AMF on the growth of horticultural crops, we compared mycorrhizal and non-mycorrhizal plants, lettuce (Lactuca sativa L.), that were inoculated with AMF propagules. As compared to the AMF- seedlings, in AMF+ seedlings at 3 weeks after sowing, the number of leaves increased 9%, leaf fresh weight increased 59%, leaf area increased 58%, and leaf length and width increased 21-22%, and chlorophyll content increased 2%. Furthermore, at 9 weeks after sowing, compared to the AMF- plants, in lettuce plants inoculated with AMF at the sowing and transplanting stages, the number of leaves increased 21% and 18%, leaf fresh weight increased 51% and 41%, root fresh weight increased 56% and 47%, and chlorophyll content increased 18% and 19%, respectively. Further this experiment indicated that the growth responses of lettuce plants inoculated with AMF during transplanting were similar to those inoculated with AMF during sowing. The results imply that the AMF infection timepoint is not important. The P content in the leaves of lettuce plants inoculated with AMF during transplanting was significantly higher (217%) than that of leaves from lettuce plants not inoculated with AMF. In contrast, the P content of the leaves of lettuce plants inoculated with AMF during the sowing stage was similar to that of leaves of control lettuce plants. In this experiment, P and chlorophyll content in AMF+ lettuce plants were higher than in AMF- plants, indicating that the photosynthetic rate was improved with AMF inoculation.