• 한국토양비료학회지
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• 제45권3호
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• pp.428-434
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• 2012

A fungal strain, capable of solubilizing insoluble phosphate under diverse temperature, pH and salt conditions was isolated from Waste Mushroom bed of Agaricus bisporus in South Korea. Based on 18S rRNA analysis, the strain was identified as Aspergillus awamori bxq33110. The strain showed maximum phosphate solubilization in AYG medium (525 ${\mu}g\;mL^{-1}$) followed by NBRIP medium (515 ${\mu}g\;mL^{-1}$). The strain solubilized $Ca_3(PO_4)_2$ to a greater extent and rock phosphate and $FePO_4$ to a certain extent. However $AlPO_4$ solubilizing ability of the strain was found to be very low. Glucose at the rate of 2% ($561{\mu}g\;mL^{-1}$) was found be the best carbon source for Aspergillus awamori bxq33110 to solubilize maximum amount of phosphate. However, no significant difference ($P{\leq}0.05$) in phosphorus solubilization was found between 1% and 2% glucose concentrations. $(NH_4)_2SO_4$ was the best nitrogen source for Aspergillus awamori bxq33110 followed by $NH_4Cl$ and $NH_4NO_3$. At pH 7, temperature $30^{\circ}C$ and 5% salt concentration (674 ${\mu}g\;mL^{-1}$) were found to be the optimal conditions for insoluble phosphate solubilization. However, strain Aspergillus awamori bxq33110 was shown to have the ability to solublize phosphate under different stress conditions at $30-40^{\circ}C$ temperature, pH 7-10 and 0-10% salt concentrations indicating it's potential to be used as bio-inoculants in different environmental conditions.

• 한국토양비료학회지
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• 제46권6호
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• pp.494-501
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• 2013

Two phosphate solubilizing Pantoea strains (P. agglomerans and P. rodasii) were employed in elucidating their phosphate solubilizing potential under different carbon and nitrogen sources, pH, temperature and salt conditions. Plant growth promoting characteristics such as ACC deaminase activity, indole acetic acid (IAA), HCN, ammonia, and siderophore production of the two strains were assessed in vitro. Potential applicability of the strains as bio-inoculants was also evaluated in pot experiments conducted under green house conditions. Phosphate solubilization measured as the amount of phosphorous released into the medium was recorded as 810 and $788{\mu}g\;ml^{-1}$ respectively by P. agglomerans and P. rodasii. Glucose at the rate of 2% was found be the best carbon source, while $(NH_4)_2SO_4$ was the best nitrogen source for both strains. Despite a slight decrease in phosphate solubilization observed at higher temperature, pH and salt concentrations, both strains could withstand against a range of temperature ($30-35^{\circ}C$), pH (7-9) and the presence of NaCl (up to 5%) without much compromising the phosphate solubilization. Different plant growth promoting traits (ACC deaminase activity, IAA, HCN, ammonia, and siderophore production) of the strains and their ability to promote the growth of green gram seedlings indicate that both strains possess high potential to be used as bio-inoculants.

• 한국토양비료학회지
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• 제49권4호
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• pp.318-326
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• 2016

Two phosphate solubilizing bacteria, Pantoea rodasii PSB-11and Enterobacter aerogenes PSB-12, were isolated from button mushroom compost and employed to assess their synergistic effect in liquid medium and on growth of green gram plants by single and co-inoculation of the strains. Co-inoculation of two strains was found to release the highest content of soluble phosphorus ($521{\mu}g\;ml^{-1}$) into the medium, followed by single inoculation of Pantoea strain ($485{\mu}g\;ml^{-1}$) and Enterobacter strain ($470{\mu}g\;ml^{-1}$). However, there was no significant difference between single inoculation of bacterial strain and co-inoculation of two bacterial strains in terms of phosphorous release. The highest pH reduction, organic acid production and glucose consumption was observed in the E. aerogenes PSB-12 single inoculated culture medium rather than those of co-inoculation. According to the plant growth promotion bioassay, co-inoculated mung bean seedlings recorded 10.6% and 10.7% higher shoot and root growth respectively compared to the control. Therefore, in concluding, co-inoculation of the strains P. rodasii and E. aerogenes displayed better performance in stimulating plant growth than inoculation of each strain alone. However, being short assessment period of the present study, we recommend in engaging further works under field conditions in order to test the suitability of the strains to be used as bio-inoculants.

• 한국토양비료학회지
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• 제49권5호
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• pp.621-626
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• 2016

The present study evaluated the variations in soil microbial population of controlled horticultural land used for lettuce (Lactuca sativa) cultivation by their fatty acid methyl ester and chemical properties. We utilized four treatment groups, no treatment (NT), culture medium (CM), Bacillus subtilis S37-2 (KACC 91281P) ${\times}10^6CFU\;mL^{-1}$ (BS1), and Bacillus subtilis $S37-2{\times}10^7CFU\;mL^{-1}$ (BS2) and analyzed these variations throughout the before treatment and harvesting stage. The chemical properties such as pH, organic matter, available phosphate, and electrical conductivity in soils before treatment and harvesting stage showed no significant difference among the treatments. Total numbers of bacteria and microbial biomass C in soil treated with BS1 were larger than those of NT, CM, and BS2, whereas total number of fungi at the harvesting stage was significantly lower in the BS1 soil than in the NT and CM soils (P < 0.05). On basis of leaf length, leaf width, leaf number and leaf weight, the growth characteristics lettuce on the soil treated with BS1 and BS2 was faster than those of NT and CM soils. Yield of lettuce with treated BS1 and BS2 were 35% and 29% more than that of NT, respectively.

• 한국토양비료학회지
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• 제47권4호
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• pp.290-298
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• 2014

A bacterial strain with the potential ability to solubilize heavy metals was isolated from heavy metal contaminated soils collected from abandoned mines of Boryeong area in South Korea. The bacterial strain with the highest degree of metal resistance was shown to have close proximity with Shewanella xiamenensis FJ589031, according to 16S rRNA sequence analysis, and selected for investigating the mobilization of metals in soil or plant by the strain. The strain was found to be capable of solubilizing metals both in the absence and in the presence of metals (Co, Pb and Cd). Metal mobilization potential of the strain was assessed in a batch experiment and the results showed that inoculation could increase the concentrations of water soluble Co, Pb and Cd by 48, 34 and 20% respectively, compared with those of non-inoculated soils. Bacterial-assisted growth promotion and metal uptake in sunflower (Helianthus annuus) was evaluated in a pot experiment. In comparison with non-inoculated seedlings, the inoculation led to increase the growth of H. annuus by 24, 18 and 16% respectively in Co, Pb and Cd contaminated soils. Moreover, enhanced accumulation of Co, Pb and Cd in the shoot and root systems was observed in inoculated plants, where metal translocation from root to the above-ground tissues was also found to be enhanced by the strain. Plant growth promotion and metal mobilizing potential of the strain suggest that the strain could effectively be employed in enhancing phytoextraction of Co, Pb and Cd from contaminated soils.

• 한국토양비료학회지
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• 제31권1호
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• pp.72-76
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• 1998

일반토양과 시설재배지 토양을 공시하여 1l 광구병에 토양 600g씩 충진하고 토양 1kg당 양송이퇴비, 계분퇴비, 돈분퇴비, 어분퇴비를 각각 0, 10, 20, 30, 40, 50g상당량을 시용하였다, 온도를 10, 20, 30, $40^{\circ}C$로 조절하고 중류수를 토양 1kg당 50, 100, 200, 300ml 첨가하여 각 처리별 아황산가스 발생량을 조사하여 다음과 같은 결과를 얻었다. 아황산가스 발생량은 황함량이 적은 양송이퇴비, 계분퇴비 및 돈분퇴비에서는 적었으나 황함량이 많은 어분퇴비 처리구에서는 10g/kg처리에서 부터 매우 큰 차이로 증가 되었다. 어분퇴비처리구는 10g이하에서도 시 용량증가에 따라서 아황산가스 발생량이 현저히 증가되었고, 황함량이 적은 일반토양보다 황 함량이 많은 시설재배지 토양에서 가스발생량이 높았다. 아황산가스 발생량은 온도가 높을수록 증가되었으며, 수분 처리별로는 150ml 첨가구에서 가장 많이 발생되었다.

• 한국토양비료학회지
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• 제48권6호
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• pp.582-587
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• 2015

This study was conducted to compare the plant growth and fruit quality of blueberries grown in different soil textures of Korea, in order to utilize the results for stable production and soil improvement. Rabbiteye blueberry cultivars 'Tifblue' and 'Baldwin' were planted and grown for three years from 2013 in wagner pot (1 $2000a^{-1}$) in a greenhouse of Namhae Sub-station, Institute of Horticultural and Herbal Science. The plants were grown in four soil textures, sand, sandy loam, loam and silt loam, and nutrient uptake and growth characteristics of plants were investigated. Leaf nitrogen and phosphorus contents of two cultivars grown in different soil textures ranged between 8.6 to $10.5gkg^{-1}$, which was lower than appropriate level for rabbiteye blueberry. However, the contents of potassium, calcium and magnesium in leaves were appropriate levels as $2.29{\sim}3.62gkg^{-1}$, $4.46{\sim}5.46gkg^{-1}$ and $1.45{\sim}2.12gkg^{-1}$, respectively. Nitrogen and phosphate contents in leaves were higher in the two cultivars grown in silt loam soil. There was no significant difference in plant volume and root dry weight among four soil textures in two cultivars. However, dry weight of leaves and branches were highest in loam soil. Fruit production was highest in loam and silt loam soil in two cultivars, showing negative correlation with the amount of sand in soil. However, sugar and acidity showed no correlation with sand content in soil. These results show the limit to the blueberry growth in soil that has no nutrient holding capacity; however, most of Korean soils that have good nutrient holding capacity can produce competitive fruits if the drainage is improved.

• 한국토양비료학회지
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• 제44권5호
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• pp.866-871
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• 2011

An auxin-producing bacteria (3YN11-02) was isolated from waste mushroom bed from Agaricus bisporus of Chungnam Buyeo-Gun area. The strain 3YN11-02 was identified as a novel species belongs to Rahnella aquatica by a chemotaxanomic and phylogenetic nalysis. The isolate was confirmed to produce indole-3-acetic acid (IAA) which is one of auxin hormone by TLC and HPLC analysis. When the concentration of IAA was assessed by performing HPLC quantity analysis, the maximal $290mg\;L^{-1}$ of IAA detected in ether fraction extracted from the culture filtrate which was cultured in R2A broth containing 0.1% tryptophan for 24 h at $35^{\circ}C$. The molecular weight of the main peak obtained by LC-mass analysis was correspondent well to 175, that of IAA. To investigate the growth promoting effect of crop, when the culture broth of R. aquatica 3YN11-02 was infected onto water culture and seed pot of mung bean, the adventitious root induction and root growth of mung bean were 2.0 times higher than control.

• 한국토양비료학회지
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• 제44권5호
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• pp.836-840
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• 2011

Cellulase와 xylanase 분비능이 우수한 고온성 부숙촉진 세균을 분리하기 위하여 진주 인근지역의 새송이버섯 재배농장으로부터 새송이버섯 수확 후 배지를 수집하였다. 새송이버섯 수확 후 배지로부터 23종의 균주를 분리하였으며 이 중 cellulase와 xylanase을 동시에 분비하는 균주를 최종 선발하여 SJ21으로 명명하였다. Bacillus ID kit와 VITEK 2 system를 이용하여 분리균 SJ21의 생리적 생화학적 특성을 조사한 결과 분리균 SJ21은 B. lincheniformis와 유사한 특징을 나타내었으며 16S rDNA 염기서열 분석결과에서는 B. subtilis와 99%의 상동성을 나타내었다. 이와 같은 결과를 종합하여 분리균 SJ21은 Bacillus sp. SJ21 로 동정되었다. 분리균이 분비하는 cellulase와 xylanase 활성은 분리균이 증식함에 따라 대수증식기 중반부터 급격히 증가하였고 정지기에 진입하면 효소활성이 더 이상증가하지 않는 것으로 나타났으며 xylanase 활성은 대수증식기 초기부터 지속적으로 증가하여 대수증식기 중반에 최대활성을 나타내었다.

• 한국토양비료학회지
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• 제43권6호
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• pp.1002-1007
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• 2010

본 연구는 균근균 접종이 포도삽목묘의 생장에 미치는 영향과 균근 형성율 그리고 형성 양상을 구명하고자 수행하였다. 포도 삽목시, 균근균 접종원을 처리한 거봉과 탐나라 품종은 무 접종처리 보다 엽수, 엽면적, 총 뿌리길이 그리고 뿌리 표면적이 크게 증가하였다. 그러나 켐벨어리 품종의 총 뿌리길이와 뿌리 표면적은 무처리구 (AMF-)와 비교하여 유의적인 차이가 없었다. 접종 8주후 균근균 접종 처리구 (AMF+)의 형성율은 22.5-32.5%이었으며, 12주 후 켐벨어리, 탐나라 그리고 거봉의 균근 형성율은 각각 29.6%, 28.8% 그리고 48.8%이었다. 반면 균근균 무처리구 (AMF-)는 균근형성 수준이 매우 낮았다.