• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1127-1142
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• 2011

The aim of this investigation was to select effective Pseudomonas sp. strains that can enhance the productivity of soybean-wheat cropping systems in Vertisols of Central India. Out of 13 strains of Pseudomonas species tested in vitro, only five strains displayed plant growth-promoting (PGP) properties. All the strains significantly increased soil enzyme activities, except acid phosphatase, total system productivity, and nutrient uptake in field evaluation; soil nutrient status was not significantly influenced. Available data indicated that six strains were better than the others. Principal component analysis (PCA) coupled cluster analysis of yield and nutrient data separated these strains into five distinct clusters with only two effective strains, GRP3 and HHRE81 in cluster IV. In spite of single cluster formation by strains GRP3 and HHRE81, they were diverse owing to greater intracluster distance (4.42) between each other. These results suggest that the GRP3 and HHRE81 strains may be used to increase the productivity efficiency of soybean-wheat cropping systems in Vertisols of Central India. Moreover, the PCA coupled cluster analysis tool may help in the selection of other such strains.

• 미생물학회지
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• 제53권4호
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• pp.242-250
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• 2017

본 연구에서는 경상북도 울릉군에서 분리한 토양 방선균에 대해 생리학적 특징과 다양성에 대해 연구하였다. ULS1 및 ULS2로 명명한 2개의 토양 시료를 채취하여 다양한 배지에 배양하여 분리하였으며, 평균 생균수는 ULS1 토양은 $1.28{\times}10^7CFU/g$, ULS2 토양은 $2.05{\times}10^7CFU/g$였다. 16S rRNA 유전자에 기반한 염기서열 분석 결과, 총 9개의 속에서 34개의 균주가 분리되었으며 해당 속은 Streptomyces (16 균주), Isoptericola (5 균주), Rhodococcus (4 균주), Agromyces (3 균주), Micrococcus (2 균주), Arthrobacter (1 균주), Williamsia (1 균주), Microbacterium (1 균주) 및 Oerskovia (1 균주)에 속하는 것을 알 수 있었다. 다양한 효소활성과 식물 생장 촉진 활성 측정 결과, 전체의 58.8%가 단백질 분해 활성을, 79.4%가 Tween 80 분해 활성을, 그리고 61.8%가 DNA 분해 활성을 각각 가지는 것으로 나타났다. Oerskovia, Williamsia, Isoptericola 및 Streptomyces 속에 속하는 분리주들로부터 인을 가용화시키는 능력을 확인할 수 있었으며, Agromyces, Oerskovia, Micrococcus, Rhodococcus, Streptomyces 및 Isoptericola 속에 속하는 분리주들은 식물호르몬인 3-indole-acetic acid (IAA)를 생산하는 것을 확인할 수 있었다. Streptomyces 속에 속하는 분리주들은 Candida albicans 뿐만 아니라 Staphylococcus aureus와 Bacillus subtilis에 항생활성을 나타내었다. 본 연구는 독특한 생태계를 구성하는 울릉도 지역의 토양 방선균 다양성 및 생리 활성에 대한 최초의 연구로서 의미를 가지며, 새로운 유용 생리 활성 물질의 좋은 원천이 될 것이라 사료된다.

• 식물병연구
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• 제29권3호
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• pp.268-275
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• 2023

본 연구에서는 누리대(Pleurospermum camtschaticum) 뿌리의 추출물을 이용하여 유기농업자재로서의 이용 가능성을 검정하기 위해 실험을 진행하였다. 먼저 누리대 뿌리 추출물을 이용하여 2,2-diphenyl-1-picrylhydrazyl (DPPH) 소거능 활성 및 환원력을 확인하였고, 고추 탄저병을 유발하는 Colletotrichum coccodes, Colletotrichum dematium에 대한 항진균 검정과 고추 종자발아 및 유묘기 생장 촉진 검정을 진행하였다. 생장 촉진 검정이 끝난 직후 처리구별 고추 잎을 채집하여, 고추 잎내의 페놀 함량을 측정하였다. 항산화 활성 검정 결과, 201.92±2.10 μg/ml에서 DPPH를 50% 이상 제거하였으며 환원력 검정 결과 역시 농도 의존적으로 증가하는 것을 확인하였다. 누리대 뿌리 추출물을 10%, 30%, 50%, 100% 비율로 희석 후에 고추 탄저병 2종(C. coccodes, C. dematium)에 대하여 균사 생장 억제 검정을 진행하였다. 누리대 뿌리 추출물 10% 비율은 2종의 탄저균에 대하여 평균 57.1% 생장 억제율을 기록하였고, 30%, 50% 비율은 농도의존적으로 억제율이 증가하였으며, 원액인 100%에서는 70.3%로 강한 균사생장의 억제력을 보였다. 고추 열매에서의 탄저균 억제 검정 결과, 앞서 실험한 균사 생장 억제 검정과 동일한 결과가 나타났으며, 탄저균만 접종한 처리구에 비하여 누리대 뿌리 추출물 50%, 100%에서 병반 면적이 80% 이상 감소한 결과를 확인하였다. 전 실험과 동일하게 원액인 100%을 포함한 10%, 30%, 50% 비율을 이용하여 고추 종자 발아 검정 및 고추 유묘기 생장 촉진 검정을 진행하였다. 농도가 낮을수록 종자의 발아가 촉진되었으며, 100% 비율에서는 종자 발아가 억제되는 현상을 보였다. 또한 고추 유묘기 생장 촉진 검정에서는 10% 비율이 대조구에 비하여 약 2배 이상의 생장 차이를 보였으며, 반대로 100% 비율에서는 생장이 억제되는 현상이 관찰되었다. 누리대 뿌리 추출물을 종자 및 식물체에 처리 시 추출물의 농도가 낮을수록 종자 발아촉진 및 식물 생장촉진 효과가 있는 것을 확인하였다. 또한 유묘기 생장 촉진 검정이 끝난 후 처리구별 고추 잎을 채집하여 병원균 항균 활성과 관련이 있는 페놀 함량을 측정한 결과, 10% 비율과 원액인 100% 비율 사이에 유의미한 결과가 나타났다. 따라서 본 연구결과는 누리대 뿌리 추출물의 향후 유기농자재로서 두 가지 가능성을 확인하였다. 추출물의 농도가 저농도일수록 작물 생장을 촉진시키는 작물 생육용으로서의 가능성을 확인하였다. 추출물의 농도가 고농도일수록 탄저균 균사 생장 억제에 효과적이기에 병해 관리용으로 이용 가능성을 확인하였지만, 종자 발아억제 및 작물에 대한 약해가 심하게 발생하였기에, 병해 관리용으로 사용하기 위해서는 작물생장의 영향이 없도록 더 많은 연구가 필요할 것으로 판단된다. 추가로 토양 내의 누리대 뿌리 추출물 처리 시 유기물 변화 및 microbiome 연구를 통하여 긍정적인 영향이 있다면 토양 개량제로서의 가능성 또한 있을 것이라 판단되며, 상당한 잠재력 가치가 있는 것으로 생각된다.

• 한국환경과학회지
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• 제22권11호
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• pp.1457-1464
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• 2013

We investigated the optimal conditions for keratinase production by feather-degrading Pseudomonas geniculata H10 using one variable at a time (OVT) method. The optimal medium composition and cultural condition for keratinase production were determined to be glucose 0.15% (w/v), beef extract 0.08% (w/v), $KH_2PO_4$ 0.12% (w/v), $K_2HPO_4$ 0.02% (w/v), NaCl 0.07% (w/v), $MgSO_4{\cdot}7H_2O$ 0.03%, $MgCl_2{\cdot}6H_2O$ 0.04% along with initial pH 10 at 200 rpm and $25^{\circ}C$, respectively. The production yield of keratinase was 31.6 U/ml in an optimal condition, showing 4.6-fold higher than that in basal medium. The strain H10 also showed plant growth promoting activities. This strain had ammonification activity and produced indoleacetic acid (IAA), siderophore and a variety of hydrolytic enzymes such as protease, lipase and chitinase. Therefore, this study showed that P. geniculata H10 could be not only used to upgrade the nutritional value of feather wastes but also useful in situ biodegradation of feather wastes. Moreover, it is also a potential candidate for the development of biofertilizing agent applicable to crop plant soil.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.958-963
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• 2008

A series of experiments were conducted to assess the effectiveness of rhizobacteria containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase for growth promotion of peas under drought conditions. Ten rhizobacteria isolated from the rhizosphere of different crops (peas, wheat, and maize) were screened for their growth promoting ability in peas under axenic condition. Three rhizobacterial isolates, Pseudomonas fluorescens biotype G (ACC-5), P. fluorescens (ACC-14), and P. putida biotype A (Q-7), were selected for pot trial on the basis of their source, ACC deaminase activity, root colonization, and growth promoting activity under axenic conditions. Inoculated and uninoculated (control) seeds of pea cultivar 2000 were sown in pots (4 seeds/pot) at different soil moisture levels (25, 50, 75, and 100% of field capacity). Results revealed that decreasing the soil moisture levels from 100 to 25% of field capacity significantly decreased the growth of peas. However, inoculation of peas with rhizobacteria containing ACC deaminase significantly decreased the "drought stress imposed effects" on growth of peas, although with variable efficacy at different moisture levels. At the lowest soil moisture level (25% field capacity), rhizobacterial isolate Pseudomonas fluorescens biotype G (ACC-5) was found to be more promising compared with the other isolates, as it caused maximum increases in fresh weight, dry weight, root length, shoot length, number of leaves per plant, and water use efficiency on fresh and dry weight basis (45, 150, 92, 45, 140, 46, and 147%, respectively) compared with respective uninoculated controls. It is highly likely that rhizobacteria containing ACC deaminase might have decreased the drought-stress induced ethylene in inoculated plants, which resulted in better growth of plants even at low moisture levels. Therefore, inoculation with rhizobacteria containing ACC deaminase could be helpful in eliminating the inhibitory effects of drought stress on the growth of peas.

• The Plant Pathology Journal
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• 제20권3호
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• pp.172-176
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• 2004

Bacterial isolates TRL2-3 and TRK2-2 showing anti-fungal activity in vitro test against some plant pathogens were identified as Pseudomonas putida and Micrococcus luteus, respectively. Pre-treatment with both bacterial isolates at the concentration 1.0$\times$ $10^7$ and $10^6$cfu/ml in the rhizosphere could trigger induced systemic resistance in the aerial part of cucumber plants against anthracnose caused by Colletotrichum orbiculare. However, the pre-treatment with the higher concentration at 1.0 $\times$ $10^8$ cfu/ml of both isolates could not induce resistance after challenge inoculation with C. orbiculare. As a positive control, the treatment with DL-3 amino butyric acid caused a remarkable reduction of disease severity whereas the lesions on the leaves of untreated plants developed apparently after the fungal inoculation. From these results, it was recomended that disease control using both bacterial isolates inducing systemic resistance in the field where chemical application is forbid.

• 한방안이비인후피부과학회지
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• 제15권2호
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• pp.80-103
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• 2002

To screen the effective materials for hair loss treatment, several natural extracts were tested using in vivo and in vitro test models. Firstly, all test materials were applicated onto the back skin of C57BL／6 mouse and then hair growth pormoting effect were measured using hair growth index As a result, Polygonum muitifiorum Thunb and Terrninalia chebula Retz. showed potent hair growth promoting effect, ranking as 1.5-2.0 of hair growth index. However, there were no plant extracts, which have remarkable potential of growth promotion of human hair dermal papilla cells cultured in vitro. In the experiments of 5${\alpha}$-reductase type Ⅱ inhibition assay, Morus alba L., Chaenomelis Fructus, Saussureae Radix, Angelicae Gigantis Radix, Polygonum multifiorum Thunb, and Angelica dahurica (Fischer) Bentham et Hooker f. showed effective potential to inhibit the activity of 5${\alpha}$-reductase type Ⅱ. To investigate the possible involvement of effects of several plant extracts on the gene expression of growth factors in human hair dermal papilla cells, RT-PCR analyses were performed. As a consequences, Mentha haplocalyx Briq., Cimicifuga foetida L., Eclipta prostrata (L.) L., Pinus densiflora S. et. Z, and Polygonum muitifiorum Thunb revealed the regulatory roles on the expression of growth factors such as IGF-I, KGF, HGF and VEGF in the dermal papilla cells. Another test for inhibition of microbial such as P. acne and P. ovale were also carried out to find whether these plant extracts have anti-microbial activities. Morus alba L. and Chaenomelis Fructus showed anti-microbial effects on Propionibacterium acnes, which is believed as a pathogen of acne. Together, these results showed several plant extracts can be used for hair growth promotion.

• 한국토양비료학회지
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• 제42권Spc호
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• pp.20-28
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• 2009

생물비료는 아직도 한국에서는 생소한 용어다. 한국에서 생물비료라 함은 식물추출액, 퇴비류-다양한 형태의 미생물 혼합제 등으로 인식되고 있다. 그러나 최근에는 식물영양요소의 흡수나 이용도를 증진시키는 토양미생물 사용으로 언급하기도 한다. 본 개관은 식물성장을 증진시키는 것으로 알려진 PGPR 서로 다른 기작과 실질적 역할에 대하여 검토하였다.

• The Plant Pathology Journal
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• 제29권1호
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• pp.59-66
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• 2013

Colonization studies previously performed with a green-fluorescent-protein, GFP, labeled derivative of Bacillus amyloliquefaciens FZB42 revealed that the bacterium behaved different in colonizing surfaces of plant roots of different species (Fan et al., 2012). In order to extend these studies and to elucidate which genes are crucial for root colonization, we applied targeted mutant strains to Arabidopsis seedlings. The fates of root colonization in mutant strains impaired in synthesis of alternative sigma factors, non-ribosomal synthesis of lipopeptides and polyketides, biofilm formation, swarming motility, and plant growth promoting activity were analyzed by confocal laser scanning microscopy. Whilst the wild-type strain heavily colonized surfaces of root tips and lateral roots, the mutant strains were impaired in their ability to colonize root tips and most of them were unable to colonize lateral roots. Ability to colonize plant roots is not only dependent on the ability to form biofilms or swarming motility. Six mutants, deficient in abrB-, sigH-, sigD-, nrfA-, yusV and RBAM017410, but not affected in biofilm formation, displayed significantly reduced root colonization. The nrfA- and yusV-mutant strains colonized border cells and, partly, root surfaces but did not colonize root tips or lateral roots.

• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.856-863
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• 2013

Application of rhizospheric fungi is an effective and environmentally friendly method of improving plant growth and controlling many plant diseases. The current study was aimed to identify phytohormone-producing fungi from soil, to understand their roles in sesame plant growth, and to control Fusarium disease. Three predominant fungi (PNF1, PNF2, and PNF3) isolated from the rhizospheric soil of peanut plants were screened for their growth-promoting efficiency on sesame seedlings. Among these isolates, PNF2 significantly increased the shoot length and fresh weight of seedlings compared with controls. Analysis of the fungal culture filtrate showed a higher concentration of indole acetic acid in PNF2 than in the other isolates. PNF2 was identified as Penicillium sp. on the basis of phylogenetic analysis of ITS sequence similarity. The in vitro biocontrol activity of Penicillium sp. against Fusarium sp. was exhibited by a 49% inhibition of mycelial growth in a dual culture bioassay and by hyphal injuries as observed by scanning electron microscopy. In addition, greenhouse experiments revealed that Fusarium inhibited growth in sesame plants by damaging lipid membranes and reducing protein content. Co-cultivation with Penicillium sp. mitigated Fusarium-induced oxidative stress in sesame plants by limiting membrane lipid peroxidation, and by increasing the protein concentration, levels of antioxidants such as total polyphenols, and peroxidase and polyphenoloxidase activities. Thus, our findings suggest that Penicillium sp. is a potent plant growth-promoting fungus that has the ability to ameliorate damage caused by Fusarium infection in sesame cultivation.