• Journal of Microbiology and Biotechnology
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• v.23 no.7
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• pp.1004-1014
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• 2013

Six nonpathogenic fungal strains isolated from alkaline soils of Buenos Aires Province, Argentina (Acremonium murorum, Aspergillus sidowii, Cladosporium cladosporoides, Neurospora tetrasperma, Purpureocillium lilacinum (formerly Paecilomyces lilacinus), and Westerdikella dispersa) were tested for their ability to produce keratinolytic enzymes. Strains were grown on feather meal agar as well as in solid-state and submerged cultures, using a basal mineral medium and "hair waste" as sole sources of carbon and nitrogen. All the tested fungi grew on feather meal agar, but only three of them were capable of hydrolyzing keratin, producing clear zones. Among these strains, P. lilacinum produced the highest proteolytic and keratinolytic activities, both in solid-state and submerged fermentations. The medium composition and culture conditions for the keratinases production by P. lilacinum were optimized. Addition of glucose (5 g/l) and yeast extract (2.23 g/l) to the basal hair medium increased keratinases production. The optimum temperature and initial pH for the enzyme production were $28^{\circ}C$ and 6.0, respectively. A beneficial effect was observed when the original concentration of four metal ions, present in the basal mineral medium, was reduced up to 1:10. The maximum yield of the enzyme was 15.96 $U_c/ml$ in the optimal hair medium; this value was about 6.5-fold higher than the yield in the basal hair medium. These results suggest that keratinases from P. lilacinum can be useful for biotechnological purposes such as biodegradation (or bioconversion) of hair waste, leading to a reduction of the environmental pollution caused by leather technology with the concomitant production of proteolytic enzymes and protein hydrolyzates.

• Journal of Soil and Groundwater Environment
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• v.22 no.6
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• pp.12-21
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• 2017

A pot experiment was conducted to investigate the transfer of As and cationic heavy metals (Fe, Mn, Zn, Cd and Pb) from soil to rice plant in soil condition with submerged and drained. During the ninety-day monitoring period for soil solution, solubility of reducible elements such as As, Fe and Mn in submerged condition were higher than that of Zn. On the contrary, concentration of Zn in drained condition was higher than that of reducible elements. The concentration of As, Cd, Pb and Zn in rice plant (root, stem, leaf and grain) showed similar pattern with soil solution. The As concentration in each part of rice plant, which cultivated in drained condition, measured 56%~94% lower than those in submerged condition. However, the contents of cationic heavy metals (Cd, Pb and Zn) were represented the opposite result with As. These results are due to mobility of As and cationic heavy metals under different soil drainage conditions which represent oxidation and reduction. Thus soil drainage control can be used as acceptable passive treatment methods to reduce transfer of inorganic contaminants from soil to rice plant. However more detailed examination on soil condition conversion is needed, because yield of rice was decreased when it cultivated in drained condition only. It also needed when soil is contaminated by As and cationic heavy metal because single drainage condition cannot reduce transfer of both kinds of contaminants all.

• Journal of the Korean Geotechnical Society
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• v.28 no.11
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• pp.79-86
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• 2012

Cemented soils have been used for subbase or base materials of roads, backfill materials of retaining walls and cofferdam. Such cemented soils can be degraded due to repeated wetting and drying or various weathering actions. Unlike rocks, a standard method was not defined for evaluating the durability of cemented soils. In this study, a slaking durability test and an ultrasound cleaner were used for developing a new durability test method for cemented soils. For durability tests, cemented sands with different cement ratios (4, 6, 8, and 12%) with cylindrical specimens were prepared and then air cured or under-water cured for three days. Three-day-cured specimens were dried for one day and then submerged for one day before testing. The weight loss after the slake durability test or ultrasonic cleaner operation for 10 or 20 min was measured and used for assessing durability. When a cement ratio was 4%, the weight loss from ultrasonic cleaner test was 7-25% but that from slake durability test was as much as 30-60%. For specimens with cement ratio of more than 8%, the weight loss was less than 10% from both tests. A durability index increased with increasing a cement ratio. The durability index of under-water cured specimen was higher than that of air cured specimen. The ultrasonic cleaner test was found to be an effective tool for durability assessment of cemented sands rather than the slake durability test.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.2
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• pp.109-115
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• 1991

This study examines the effect of submergence on phosphorus adsorption characteristics in Gangseo(paddy soil), Yesan(non-cultivated soil), and Jungdong soil(upland soil). The soils were submerged with glucose sol'n at $28^{\circ}C$ for 17 days. After the submergence, the phosphorus adsorption was conducted at three temperatures(5, 25 and $45^{\circ}C$). The phosphorus adsorption maximum($X_m$) and the equilibrium constant(K) were obtained by Langmuir adsorption isotherm, and the heat of adsorption(${\Delta}H$) was calculated by van't Hoff's equiation. Results obtained are as follows ; 1. The amounts of adsorbed P were increased with temperature, but the effects of temperature on rate of P adsorption were very small in all three soils. 2. By submergence, $X_m$ were increased from 500mg P/kg to 850mg P/kg in Gangseo soil, from 1,850mg P/kg to 3,300mg P/kg in Yesan soil, and from 310mg P/kg to 670mg P/kg in Jungdong soil. But the effects of temperature on $X_m$ were very small in all three soils. 3. Submergence decreased K for Gangseo and Yesan soils, but increased for Jungdong soil. Whereas K were increased with temperature in all three soils. 4. By submergence, ${\Delta}H$ for Gangseo soil was greatly increased (from 2.2 Kcal/mole to 3.5 Kcal/mole), whereas that for Yesan soil changed little (from 5.7 Kcal/mole to 5.5 Kcal/mole). It was 4.4 Kcal/mole in submerged Jungdong soil.

• Mycobiology
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• v.47 no.1
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• pp.12-19
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• 2019

In order to elucidate the fungal diversity and community structure in freshwater environments, numerous fungal strains were isolated from freshwater, submerged soils, twigs, dead insects, etc. Among them, the present study has focused specifically on Aspergillus, Penicillium, and Talaromyces species, which produce diverse useful metabolites in general. Twelve strains of Aspergillus isolated were identified as A. japonicus (n = 5), A. tubingensis (3), A. niger (2), and A. flavus (2), 10 strains of which belong to Aspergillus section Nigri, named black Aspergillus. Eight strains of Penicillium were identified as P. brasilianim (n = 3), P. oxalicum (2), P. crustosum (1), P. expansum (1), and P. piscarium (1). Two different strains of Talaromyces were identified as T. pinophilus and T. versatilis. Thus far, Penicillium piscarium and Talaromyces versatilis have been unrecorded in Korea, for which we provide detailed morphological and molecular characteristics.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.77-81
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• 2007

In order to minimize the mycelial pellet size of a high phosphate-solubilizing fungus, Aspergillus sp. PS-104 in liquid media, one of the critical obstacles during the submerged culture of filamentous fungi, an investigation was focused on the culture conditions (media and inoculum size) and additives (different soils, surfactants and polyethylene glycol 200). When the fungus was cultured in PDB, SDB and YPD media. their pellet sizes decreased in the order of SDB=YPD>PDB. At the higher concentrations of initial inoculum ranging from $1{\times}10^3$ to $1{\times}10^7$ conidia/ml, the smaller size of pellet was formed in the PDB medium. In addition, the pellet size was effectively reduced by 1/6${\sim}$1/4 by the addition of 0.1% soil containing zeolite, diatomite, loess, kaoline and talc, excluding bentonite. The addition of 0.1% Tween 80, Triton X-100 and PEG 200 also decreased the pellet size, but SDS completely inhibited the fungal growth.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.3
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• pp.235-241
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• 1983

Major cation uptake by the rice plant and its leachates in submerged condition were studied at 3 different levels of potassium and nitrogen application with three texture soils (Clay loam, Loam, Sandy loam) by pot experiment. The results are as follows. 1. Potassium uptake and grain yields of rice plant were increased and calcium and magnesium uptake of rice plant were decreased by application of potassium. 2. The potassium application caused to increase Ca, Mg, K and $NH_4$ Content in leachate. 3. In the rice leaf at heading stage, the optimum cation ratios of K/Ca, K/Mg in me and $K_2O/N$ in % at N 3.3g/pot level were 1.59, 4.26 and 3.62, respectively, but the ratios were increased to 1.65, 4.32 and 3.94 at high level of nitrogen. 4. Similar trends of cation ratios were found in rice straw. leaching soil solution and soils after harvest by potassium application.

• Korean Journal of Environmental Agriculture
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• v.12 no.2
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• pp.121-128
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• 1993

In order to elucidate the degradation of the herbicide bentazon (3-isopropyl-2,1,3-benzothiadiazin-4-one-2,2-dioxide) by soil microorganisms, it was incubated at $23{\pm}1^{\circ}C$ under the submerged and upland soil conditions of the different soils in the Chung Buk area. When bentazon (200 ppm) was incubated in Cheong Won A soil (silty loam; pH, 5.2; organic matter 1.4%) under the submerged condition for 6 months, 6-hydroxy bentazon (1.27%) was formed as the major degradation product and 8-hydroxy bentazon (0.57%) and anthranilic acid (0.13%) were formed as the minor ones. Meanwhile, when 500 ppm of bentazon was incubated in the same soil for 2 months, a trace amount of 6-hydroxy bentazon was formed. Eight strains of microorganisms isolated from the soils did not give any distinct degradation products in the pure culture experiment. The greater dehydrogenase activity in Cheong Won A soil than in Cheong Ju A soil might be related to the greater bentazon-degradability of the former soil than that of the latter. When bentazon (10 ppm) was incubated for 14 days with 14 strains of bacteria and 8 strains of fungi, the identities of which were all known, Rhizopus stolonifer produced 4.6${\sim}$31.6% of anthranilic acid as the major product from batch to batch, with trace amounts of 6-hydroxy bentazon and 8-hydroxy bentazon as minor products. The rest microorganisms did not produce any noticeable products.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.3
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• pp.286-293
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• 1983

The glucose application remarkably increased the heterotrophic acetylene reducing activities during one month incubation. The amount of the increases varied between the soils. Application of rice straw brought about the significant increases during incubation time. Compost contained the largest amount of available-N among the C-sources, and thereby brought the smallest increase in all soils. The cumulative fixed nitrogen with application of rice straw at 30 days incubation in the three experimented soils were highest in Hwadong clay soil, i.e, $2.2mg^N/100g$, intermediate in Ratchaburi soil $0.85mg^N$, and least in Konosu soil $0.80mg^N/100g$. On the other hand, nitrogen fixing heterotrophic, bacteria, such as Clostridia, aerobes and anaerobes, were remarkably increased by application of rice straw while Azotobacter and Beijerinkia were not. The cumulative fixed nitrogen was more pronounced in the clay soil than in the coarse loamy soil. More pronounced nitrogen fixing activities in light condition(heterotrophic + photosynthetic) than that in dark(heterotrophic) condition have been observed both in the coarse loamy and clay soils. The nitrogen fixing ability of photosynthetic microbes in paddy soil is probably higher in coarse loamy soil than in clay soil.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.1-7
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• 2010

This study was carried out to investigate plow pan characteristics and to grasp the relationship between its particle size distribution fractal dimension ($D_m$) and water transport in paddy plow pan. Twenty four soil sampling sites with different management groups, ordinary and sandy-textured, were selected and investigated for physical properties of soils such as Yamanaka hardness in April, non-submerged condition, before rice seedling transplanting. The plow pan appearing depth and thickness was determined by penetration resistance profile. Undisturbed core samples with five replicates were sampled at plow pan layerwith 2 inch cores for measuring soil bulk density and saturated hydraulic conductivity. The particle size distribution fractal dimension ($D_m$) was calculated by the method following the procedure Tylerand Wheacraft (1992), using the USDA-based particle size analysis datawith fractions of 0-0.002, 0.002-0.053, 0.053-0.1, 0.1-0.25, 0.25-0.5, 0.5-1.0, and 1.0-2.0 mm. The plow pan of investigated fields appeared at a range from 5 to 30 cm depth, showing minimum value in sandy-textured management group and maximum value in ordinary management group. The thickness of plow pan were distributed from 5 to 17 cm, showing both minimum and maximum values in sandy-textured management group. Averagely, the plow appearing depth were deeper in ordinary management group than in sandy-textured management group, whereas the reverse in the thickness of plow pan. The particle size distribution fractal dimension ($D_m$) had higher value with finer textures, with higher fractality in coarser texture. Saturated hydraulic conductivities, $K_s$, of plow pan soils distributed from 0.5 to 1420 mm $day^{-1}$, having the highest value in sandy skeletal soils. The $K_s$ decreased with decreasing clay content and $D_m$, showing power function relationships. The coefficient of determination, $R^2$, of the fitted power functions were higher in $D_m$ as x-axis than in clay content. This means that $D_m$ could give us more effective estimation than clay content. Especially, sandy-textured paddy soils had higher $R^2$, compared to ordinary paddy soils. $K_s$ of relatively coarse-textured soils with less than 18%of clay content, therefore, was more dependent on particle size distribution than that of relatively fine-textured soils. From these results, it could be concluded that the fractal scaling gives us a unique quantity describing particle size distribution and then can be applied to estimate saturated hydraulic conductivity, especially more effective in coarse-textured soils.