• Journal of Applied Biological Chemistry
• /
• 제64권4호
• /
• pp.333-341
• /
• 2021

본 연구는 근권 토양 및 뿌리에 존재하는 근권 미생물 중 미생물 제제로 적합한 균주를 선별하기 위해서 미네랄 가용화능, 10종의 식물 병원성 곰팡이에 대한 항진균 활성 및 식물 생장 촉진 활성을 평가하였다. 결과적으로 불용성 인산, 탄산칼슘, 규소 및 아연 가용화능과 질소고정능, siderophore, indole-3-acetic acid와 aminocyclopropane-1-carboxylate deaminase 생성능 및 7종의 식물 병원성 곰팡이에 대해 항진균 활성을 갖는 DDP346을 선별하였다. 선별된 DDP346은 Acinetobacter pittii DSM21653 (NR_117621.1)와 99.9% 이상의 높은 상동성을 보였으며, 16S rRNA 염기서열을 바탕으로 계통도를 분석한 결과에서도 Acinetobacter pittii와 높은 유연관계를 나타내었다. DDP346의 생장 조건은 온도(10-40 ℃), pH (5-11) 염농도(0-5%) 범위로 확인하였다. 또한 pH 변화와 가용화된 인산 함량 간에 음의 상관계수(r²= -0.913, p <0.01)를 나타내는 것을 확인하였는데, 이는 배양 중에 생성되는 유기산에 의한 것으로 추정된다. 결과적으로 미네랄 가용화능, 식물 병원성 곰팡이에 대한 항진균 활성 및 식물 생장 촉진 활성 평가를 통해 Acinetobacter sp. DDP346을 다목적 미생물 제제로써 활용 가능성을 제시한다.

• 한국미생물·생명공학회지
• /
• 제49권3호
• /
• pp.403-412
• /
• 2021

본 연구에서는 토양 및 근권에 존재하는 Bacillus 속의 식물 생장 촉진 활성, 식물 병원성 곰팡이의 생장 억제활성, 미네랄 가용화능 및 세포 외 효소활성을 확인해 보고자 하였다. 식물 병원성 곰팡이에 대한 항진균 활성에서 DDP257은 10종의 병원성 곰팡이에서 항진균 활성이 모두 나타났다. 식물 생장 촉진 인자인 indole-3-acetic acid 생성능에서는 ANG20이 70.97 ㎍/ml로 가장 높게 나타났다. 추가적으로 1-aminocyclopropane-1-carboxylate deaminase 생성능 조사에서는 총 10종에서 생성능을 확인하였고, 질소 고정능과 siderophore 생성능 조사에서는 대부분의 분리균주에서 활성을 확인하였다. 이후 분리된 균주에 대하여 phosphate, calcite, zinc과 같은 미네랄 가용화능을 확인하였으며 세포외 효소활성에서도 대부분의 효소에서 활성이 나타났다. 특히 alkaline phosphatase, esterase (C4), acid phosphatase, naphtol-AS-BI-phosphohydrolase에서 선별된 균주 모두 유사한 활성을 보였다. 이는 Bacillus 속이 다양한 유기물과 항생물질 및 세포 외 효소를 분비함으로써 이러한 결과가 나타난 것으로 판단된다. 따라서, 본 연구 결과를 통해 토양의 환경 개선에 기여하는 균주를 활용하여 미생물 제제로써의 가능성을 제시한다.

• Journal of Microbiology and Biotechnology
• /
• 제19권1호
• /
• pp.99-107
• /
• 2009

Strain PUPC1 produces an antifungal protease as well as plant growth promoting enzymes such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase and phosphatase. Morphological, cultural, and physiological characteristics as well as 16S rRNA gene-sequence-based phylogenetic analysis confirmed the taxonomic affiliation of PUPC1 as Chryseobacterium aquaticum. The optimum growth of PUPC1 was observed at pH 6.0 and $30^{\circ}C$, and maximum protease production was observed in medium B amended with 1% tryptone, 0.5% sucrose, and 0.005% $MnCl_2$. The protease was purified by ammonium sulfate precipitation, Sephadex G-75 gel filtration chromatography, and electroelution from preparative SDS-PAGE. The protease had a molecular mass of 18.5 kDa. The optimum pH and temperature stability of the protease were pH 5.0-10.0 and temperature $40-70^{\circ}C$. Chryseobacterium aquaticum PUPC1 and its protease showed a broad-spectrum antifungal activity against phytopathogenic fungi. Strain PUPC1 also exhibited plant growth promoting traits. The objective of the present investigation was to isolate a strain for agricultural application for plant growth promotion and biocontrol of fungal diseases.

• 생명과학회지
• /
• 제31권7호
• /
• pp.641-653
• /
• 2021

본 연구에서는 근권토양으로부터 18종의 세균을 순수분리하고, 이들의 식물 병원성 진균 생육억제 활성, 식물생장촉진 활성 및 미네랄 가용화능을 평가하였다. Bacillus 속과 Pseudomonas 속 분리균주의 항진균 활성을 통해 생물학적 방제제로서의 가능성을 확인할 수 있었으며, 이는 식물 병원성 진균의 세포벽에 작용하는 여러 가수분해효소 활성과 siderophore 생성능 등에 기인된 것으로 판단된다. 또한 대부분의 분리균주가 aminocyclopropane-1-carboxylate deaminase 생성능, indole-3-acetic acid 생성능 및 질소 고정능을 갖고 있는 것으로 나타났으며, 이러한 특성은 식물이 흔히 노출될 수 있는 환경 스트레스 조건 하에서 스트레스 에틸렌의 농도를 감소시킴으로써 뿌리 발달 및 성장, 그리고 작물의 생산성에 긍정적인 영향을 줄 것으로 판단된다. 그리고 분리균주의 인산, 규소, 탄산칼슘, 아연 가용화능 등을 확인한 결과, 일부 분리균주들의 미네랄 가용화능을 확인하였으며, 이들 분리균주를 식물 생장 시에 접종한다면 식물 생장에 필요한 영양분을 식물이 흡수할 수 있는 이용가능한 형태로 변환시켜 식물의 생장에 도움을 줄 수 있을 것으로 기대된다. 이러한 항진균 활성, 식물생장촉진 활성 및 미네랄 가용화능의 결과를 통해 분리균주 18종의 biocontrol agent로서의 이용가능성을 제시하고자 한다.

• 한국토양비료학회지
• /
• 제45권1호
• /
• pp.37-42
• /
• 2012

Improvement of plant growth by Methylotrophic bacteria can be influenced through alterations in growth modulating enzymes or hormones, especially by decreasing ethylene levels enzymatically by 1-aminocyclopropane-1-carboxylate (ACC) deaminase or by production of indole-3-acetic acid (IAA). In this study, the effect of seven strains of Methylobacterium on seedling ethylene emission of tomato and red pepper plants was evaluated under greenhouse condition. Ethylene emission was lowest in Methylobacterium oryzae CBMB20 inoculated tomato plants and CBMB110 inoculated red pepper plants at 47 days after sowing (DAS). However, at 58 DAS all inoculated plants showed almost similar pattern of ethylene emission. Methylobacterium inoculated tomato and red pepper plants showed significantly less ethylene emission compared to control. Our results demonstrated that Methylobacterium spp. inoculation promotes plant growth due to the reduction of ethylene emission and therefore can be potentially used in sustainable agriculture production systems.

• Journal of Plant Biotechnology
• /
• 제4권1호
• /
• pp.7-15
• /
• 2002

Eight cDNAs corresponding to fruit-specific genes were isolated from ripened melon through differential screening. Sequence comparison indicated that six of these cDNAs encoded proteins were previously characterized into aminocyclopropane-1-carboxylate (ACC) oxidase, abscisic acid, stress and ripening inducible (ASR) gene, RINC-H2 zinc finger protein, pyruvate decarboxylase, or polyubiquitin. RFS2 and RFS5 were the same clone encoding polyubiquitin. The other cDNAs showed no significant homology with known protein sequences. The ASR homologue (Asr1) gene was further characterized on the cDNA and genomic structure. The deduced amino acid sequence had similar characteristics to other plant ASR. The Asr1 genomic DNA consisted of 2 exons and 1 intron, which is similar to the structure of other plants ASR genes. The promoter region of the Asr1 gene contained several putative functional cis-elements such as an abscisic acid responsive element (ABRE), an ethylene responsive element (ERE), a C-box or DPBf-1 and 2, Myb binding sites, a low temperature responsive element (LTRE) and a metal responsive element (MRE). The findings imply that these elements may play important roles in the response to plant hormones and environmental stresses in the process of fruit development. The results of this study suggest that the expressions of fruit specific and ripening-related cDNAs are closely associated with the stress response.

• 한국유기농업학회지
• /
• 제26권3호
• /
• pp.463-475
• /
• 2018

국내 일부 시설재배지는 장기간 과도한 양분 투입 등에 의한 염류 집적 현상이 문제가 되어왔으며, 최근 이상기온에 따른 온도장해에 의한 피해도 발생하고 있다. 이러한 현상에 대해 친환경적으로 대처하기 위하여 고염류와 온도 스트레스에 대해 작물에 내성을 증강시키는 미생물을 선발하였다. 국내 토양에서 분리한 1,944균주중 고염류 또는 온도 스트레스 조건에서 세균의 생장과 식물생장촉진 관련 특성(IAA 생성, ACC deaminase 활성, 인산가용화능)을 고려하여 20균주를 1차 선발(전체 균주의 1.03%)하였다. 1차 선발한 20균주 중 토마토 식물검정을 통해 고염류 또는 온도스트레스에 대한 내성을 유도하는 7세균(1차 선발균주의 35%, 전체 균주의 0.36%)을 단계적으로 선발할 수 있었다. 선발된 세균은 16S rRNA 유전자의 염기서열 분석을 통해 모두 Bacillus 속에 속하는 것으로 확인되었다. 이러한 결과로 선발된 7균주는 토마토의 고염류 또는 온도 스트레스에 대한 효과적인 미생물 제제로 활용이 가능한 것을 확인할 수 있었다.

• Journal of Microbiology and Biotechnology
• /
• 제29권11호
• /
• pp.1777-1789
• /
• 2019

Drought is more concerned to be a huge problem for agriculture as it affects plant growth and yield. Endophytic bacteria act as plant growth promoting bacteria that have roles for improving plant growth under stress conditions. The properties of four strains of endophytic bacteria were determined under water deficit medium with 20% polyethylene glycol. Bacillus aquimaris strain 3.13 showed high 1-aminocyclopropane-1-carboxylate (ACC) deaminase production; Micrococcus luteus strain 4.43 produced indole acetic acid (IAA). Exopolysaccharide production was high in Bacillus methylotrophicus strain 5.18 while Bacillus sp. strain 5.2 did not show major properties for drought response. Inoculation of endophytic bacteria into plants, strain 3.13 and 4.43 increased height, shoot and root weight, root length, root diameter, root volume, root area and root surface of Jerusalem artichoke grown under water limitation, clearly shown in water supply at 1/3 of available water. These increases were caused by bacteria ACC deaminase and IAA production; moreover, strain 4.43 boosted leaf area and chlorophyll levels, leading to increased photosynthesis under drought at 60 days of planting. The harvest index was high in the treatment with strain 4.43 and 3.13 under 1/3 of available water, promoting tuber numbers and tuber weight. Inulin content was unchanged in the control between well-watered and drought conditions. In comparison, inulin levels were higher in the endophytic bacteria treatment under both conditions, although yields dipped under drought. Thus, the endophytic bacteria promoted in plant growth and yield under drought; they had outstanding function in the enhancement of inulin content under well-watered condition.

• 한국환경과학회지
• /
• 제29권9호
• /
• pp.925-933
• /
• 2020

To develop eco-friendly microbial inoculants, siderophore-producing bacteria were isolated and identified, and their production characteristics and plant growth-promoting abilities were investigated. A strain S21 was isolated from rhizosphere of Korean perilla (Perilla frutescens) and identified as Enterobacter amnigenus by phenotypic properties and 16S rRNA gene sequencing. The highest siderophore production was obtained in a medium containing 0.5% fructose, 0.1% urea, 0.5% K₂HPO₄ and 0.1% succinic acid. By using this improved medium, siderophore production increased by 2.5 times compared to that of basal medium. The strain S21 showed insoluble phosphate solubilizing, ammonification and antifungal activities, and also produced hydrolytic enzymes (protease and lipase), indoleacetic acid and 1-aminocyclopropane-1-carboxylate deaminase. Our data suggest that E. amnigenus S21 is a potential candidate that can be used as eco-friendly biocontrol agent and biofertilizer.

• 한국토양비료학회지
• /
• 제49권4호
• /
• pp.355-367
• /
• 2016

Soil salinization refers to the buildup of salts in soil to a level toxic to plants. The major factors that contribute to soil salinity are the quality, the amount and the type of irrigation water used. The presented review discusses the different sources and causes of soil salinity. The effect of soil salinity on biological processes of plants is also discussed in detail. This is followed by a debate on the influence of salt on the nutrient uptake and growth of plants. Salinity decreases the soil osmotic potential and hinders water uptake by the plants. Soil salinity affects the plants K uptake, which plays a critical role in plant metabolism due to the high concentration of soluble sodium ($Na^+$) ions. Visual symptoms that appear in the plants as a result of salinity include stunted plant growth, marginal leaf necrosis and fruit distortions. Different strategies to ameliorate salt stress globally include breeding of salt tolerant cultivars, irrigation to leach excessive salt to improve soil physical and chemical properties. As part of an ecofriendly means to alleviate salt stress and an increasing considerable attention on this area, the review then focuses on the different plant growth promoting bacteria (PGPB) mediated mechanisms with a special emphasis on ACC deaminase producing bacteria. The various strategies adopted by PGPB to alleviate various stresses in plants include the production of different osmolytes, stress related phytohormones and production of molecules related to stress signaling such as bacterial 1-aminocyclopropane-1-carboxylate (ACC) derivatives. The use of PGPB with ACC deaminase producing trait could be effective in promoting plant growth in agricultural areas affected by different stresses including salt stress. Finally, the review ends with a discussion on the various PGPB activities and the potentiality of facultative halophilic/halotolerant PGPB in alleviating salt stress.