• Journal of Plant Biotechnology
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• 제47권4호
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• pp.337-344
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• 2020

식물생장촉진 미생물은 식물 뿌리에 영양을 원활하게 공급하거나 휘발성 유기화합물(Volatile Organic Compound, VOC)를 이용하여 식물의 내재 인자와 상호작용을 통해 생장을 촉진한다. 본 연구에서는 식물 생장 촉진 진균 UOS의 담배에서의 생장 촉진 효과를 평가하고, 계통발생학적 분석을 통해 동정하였다. 또한, UOS의 식물 생장 촉진 인자를 탐색하고자 Gas Chromatography-Mass Spectrometry (GC-MS) 분석을 통해 UOS의 VOCs를 확인하였다. UOS를 처리한 담배는 무처리구에 비해서 3.8배의 생중량이 증가하였고, I-plate를 이용한 분리된 공간에서는 UOS처리구가 무처리에 비해 생중량이 4.2배 증가하였다. 또한, UOS 처리구의 식물은 주근의 길이가 약2배 짧아지고 측근의 수가 약2배 증가하였다. UOS은 포자 및 균사 형태와 Internal transcribed spacer (ITS) 유전자 염기서열을 통하여 Phoma sp.으로 동정되었으며, 이들은 GC-MS분석을 통해 UOS는 hexamethylcyclotrisiloxane (D3)라는 VOC를 갖고 있는 것이 밝혀졌다. 이 결과들은 Phoma sp.의 진균 UOS가 VOC물질인 D3을 통해서 간접적으로 식물 생장 촉진 및 뿌리 발달에 영향을 미치는 것을 나타낸다. UOS와 그의 VOC인 D3의 활용은 농업에서 생장량 증대에 기여할 것으로 판단된다.

• 한국토양비료학회지
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• 제49권3호
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• pp.251-258
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• 2016

A rhizobacterium LPN-2, which showed strong antifungal activity and auxin producing ability, was isolated from a farmland in North Gyeongsang Province, South Korea. Based on analysis of the 16S rDNA sequence, strain LPN-2 was identified as a novel strain of Burkholderia and was designated as Burkholderia sp. LPN-2. In vitro experiments showed that the isolated stain LPN-2 significantly produced auxin within 48 hr incubation. In order to check for PGPR function we performed in vivo growth promoting test in different crops, including mung bean, pea and cabbage. Application of Burkholderia sp. LPN-2 showed dramatic growth promoting effect on all the tested plants. We also confirmed siderophore and cellulase productions by Burkholderia sp. LPN-2 using CAS blue agar and CMC plate test. Further treatment with LPN-2 and the crude culture broth was effective in suppressing anthracnose in vitro test and also reduced incidence and severity of anthracnose in apple and pepper. Taken together, we conclude that Burkholderia sp. LPN-2 might be used as organic fertilizer for effective crop production in organic farming.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.190-190
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• 2017

Chemical fertilizers have been used to increase crop production and contributed to escaping food shortages. However, excessive use of chemical fertilizers over a long period caused many problems such as environmental pollution and the hampered production potential of the land. Thus, it is necessary to develop eco-friendly bio-fertilizers that can replace the use of chemical fertilizers. Here, we tested the effect of some nitrogen-fixing microorganims on the plant growth promotion. Seventy free-living nitrogen fixing microorganisms were isolated from rhizosphere of crop cultivation fields, streamside soils and sludge in Ansung, Korea. Of them, three strains (NF2-4-1, Yeast; EMM409, Mesorhizobium; Gsoil662, Burkholderia) were selected to be most efficient in the capacity of N-fixing nitrogen based on colony forming cell assay in N-free media. To investigate the ability to promote plant growth, these strains were inoculated into the soil and cabbage were grown for 4 weeks in the grown chamber. Fresh weight, dry weight, and leaf area were measured from 4-week-old plants. Phenotypic analysis revealed that the growth of the plants inoculated with NF2-4-1 and EMM409 strains were significantly promoted compared to the mock-treated control plants, while Gsoil662-inoculated plants did not show statically significant promotion. These results indicate that these nitrogen-fixing microorganims can be used to develop plant growth promoting bio-fertilizers. Further analysis on nitrogen fixing level in soil by these strains will be tested.

• The Plant Pathology Journal
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• 제39권5호
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• pp.430-448
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• 2023

Recently, strategies for controlling Fusarium oxysporum f. sp. lycopersici (Fol), the causal agent of Fusarium wilt of tomato, focus on using effective biocontrol agents. In this study, an analysis of the biocontrol and plant growth promoting (PGP) attributes of 11 isolates of loamy soil Bacillus spp. has been conducted. Among them, the isolates B.PNR1 and B.PNR2 inhibited the mycelial growth of Fol by inducing abnormal fungal cell wall structures and cell wall collapse. Moreover, broad-spectrum activity against four other plant pathogenic fungi, F. oxysporum f. sp. cubense race 1 (Foc), Sclerotium rolfsii, Colletotrichum musae, and C. gloeosporioides were noted for these isolates. These two Bacillus isolates produced indole acetic acid, phosphate solubilization enzymes, and amylolytic and cellulolytic enzymes. In the pot experiment, the culture filtrate from B.PNR1 showed greater inhibition of the fungal pathogens and significantly promoted the growth of tomato plants more than those of the other treatments. Isolate B.PNR1, the best biocontrol and PGP, was identified as Bacillus stercoris by its 16S rRNA gene sequence and whole genome sequencing analysis (WGS). The WGS, through genome mining, confirmed that the B.PNR1 genome contained genes/gene cluster of a nonribosomal peptide synthetase/polyketide synthase, such as fengycin, surfactin, bacillaene, subtilosin A, bacilysin, and bacillibactin, which are involved in antagonistic and PGP activities. Therefore, our finding demonstrates the effectiveness of B. stercoris strain B.PNR1 as an antagonist and for plant growth promotion, highlighting the use of this microorganism as a biocontrol agent against the Fusarium wilt pathogen and PGP abilities in tomatoes.

• Journal of Microbiology and Biotechnology
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• 제30권3호
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• pp.417-426
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• 2020

Bacillus amyloliquefaciens is an important plant disease-preventing and growth-promoting microorganism. B. amyloliquefaciens WS-8 can stimulate plant growth and has strong antifungal properties. In this study, we sequenced the complete genome of B. amyloliquefaciens WS-8 by Pacific Biosciences RSII (PacBio) Single Molecule Real-Time (SMRT) sequencing. The genome consists of one chromosome (3,929,787 bp) and no additional plasmids. The main bacteriostatic substances were determined by genome, transcriptome, and mass spectrometry data. We thereby laid a theoretical foundation for the utilization of the strain. By genomic analysis, we identified 19 putative biosynthetic gene clusters for secondary metabolites, most of which are potentially involved in the biosynthesis of numerous bioactive metabolites, including difficidin, fengycin, and surfactin. Furthermore, a potential class II lanthipeptide biosynthetic gene cluster and genes that are involved in auxin biosynthesis were found. Through the analysis of transcriptome data, we found that the key bacteriostatic genes, as predicted in the genome, exhibited different levels of mRNA expression. Through metabolite isolation, purification, and exposure experiments, we found that a variety of metabolites of WS-8 exert an inhibitory effect on the necrotrophic fungus Botrytis cinerea, which causes gray mold; by mass spectrometry, we found that the main substances are mainly iturins and fengycins. Therefore, this strain has the potential to be utilized as an antifungal agent in agriculture.

• 미생물학회지
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• 제52권1호
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• pp.32-39
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• 2016

독도에 자생하는 번행초의 뿌리로부터 순수 분리하여 형태적으로 상이한 17개의 내생균류를 선별하였다. 또한 분리된 균류들에 대하여 각각의 염농도와 pH 농도 구배에 따라 생장 시험을 확인하였다. 내생균류에 대해 각각 난장이벼의 유묘에 식물생장활성시험을 진행하였고, 그 결과 YH103 균주가 가장 높은 활성을 나타내었다. 계통분석은 Maximum likelihood 방법을 활용하여 결합된 ITS영역, beta-tubulin 및 calmodulin 유전자 염기서열을 분석하여 분리된 균주의 유연관계를 분석하였다. YH103 균주의 배양여과액을 HPLC와 GC/MS SIM을 이용하여 분석한 결과 식물호르몬인 지베렐린 $GA_4$, $GA_7$, $GA_8$ 및 $GA_{19}$가 확인되었다. 최종적으로 YH103 균주의 형태학적 관찰 및 결합된 유전자 염기서열의 분자적 분석을 통해 GA를 생산하는 새로운 Aspergillus tubingensis로 동정되었다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.692-700
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• 1996

The objective of this study is to develop a systematic purification plant using the metabolism of aerobic microorganisms. This system is subsequently aerated and continuously removes suspended solids and settling sludges caused by aerating pressure at the bottom of a lower pipe (i.e., Continuous Removal of Suspended solids and Settling sludges, CRSS). The CRSS plants are brought out by introducing fine air bubbles into the liquid phase of a lower pipe in the bio-reactor. These plant uses aeration pipe, with multiple inlets to sweep the floor of bio-reactor tank, instead of the conventional scraper mechanisms. The principal advantage of this system is that it can continuously remove very small or light particles that settles completely within a short time. Once the particles have been floated to the surface, they can be moved into the pipe and collected in the settling tank by sequently aerated pressure. The experimental results shows that about 99.0% of the biochemical oxygen demand(BOD), 99.3% of the suspended solid(SS), 92.3% of the total nitrogen(T-N), 99.0% of the turbidity(TU), 100% of the total coliform(TC)and ammonia was respectively removed during aerobic digestion for 9 days. These result indicates that the CRS S plants are very effective for reduction and deodorization of swine wastewater contaminants, and the efflux from CRS S can either be discharged in the river or used as nutrient solution of formulation for plant growth factories. The developed CRSS plant proved to be flexible and it can simply be adapted to any type of biological waste treatment problem.roblem.

• 한국토양비료학회지
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• 제23권1호
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• pp.67-72
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• 1990

수종(數種)의 비두과식물(非荳科植物)의 뿌리로 부터 질소고정균(窒素固定菌)을 분리(分離)하여 분리(分離)된 균(菌)에 대(對)해서 숙주식물(宿主植物)의 접종실험(接種實驗)을 하여 유효균(有效菌)의 선발(選拔)을 한 결과(結果) 1. 9개(個)의 식물(植物)에 대(對)해서는 시금치, 배추, 오이, 갓 및 가지에서 비교적(比較的) 높은 아세칠렌 환원능(還元能)을 가진 균주(菌株)를 얻었고 2. 그 중(中)에서 아세칠렌 환원능(還元能)이 큰 4개(個)의 숙주식물(宿主植物)중 시금치, 배추, 오이에서 양호(良好)한 생육(生育)을 하는 균주(菌株)를 찾았다. 특(特)히 시금치에서 접종효과(接種效果)가 현저(顯著)하였다. 3. 이상(以上)의 결과(結果)로 부터 비두과식물(非荳科植物)의 뿌리에도 약한 협생(協生)을 하는 질소고정균(窒素固定菌)이 생육(生育)되고 있어 뿌리의 생장(生長) 및 분화(分化)를 촉진(促進)시켜 지상부(地上部)의 생육(生育)을 왕성하게 하는 것으로 판단(判斷)된다.

• 한국유기농업학회지
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• 제27권1호
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• pp.65-76
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• 2019

작물생육촉진과 병 방제 기능을 지닌 Bacillus velezensis GH1-13 균주의 대량배양을 위한 최적배지(glucose 0.5%, soy bean flour 0.8%, NaCl 0.15%, $K_2HPO_4$ 0.25%, $Na_2CO_3$ 0.05%, $MgSO_4.7H_2$ 0.1%) 조성을 확립하였다. 최적배지(MMS)를 이용하여 500 L 대용량 발효기에서 배양한 결과 총 균체수 $7.5{\times}10^9cells/mL$, $6.8{\times}10^9\;endospore\;cells/mL$ 및 90% 내생포자 형성률 등 안정된 대량생산을 확인하였다. 최적배지에서 배양한 GH1-13 균체와 배양 상층액의 경우 Colletotrichum gloeosporioides를 포함한 4종의 식물병원성 곰팡이에 대한 항진균활성을 보였다. 또한 식물생육촉진 호르몬의 일종인 IAA 생산량을 비교한 결과, 최적배지에서 배양한 경우 상업용 배지(TSB, R2A)에 비해 2.5~13배 이상 높은 생산성을 보였다. 더불어, 최적배지에 0.3% tryptophan을 첨가하여 배양했을 경우 28.50 mg/L의 IAA 최대 생산량을 보였으며, 이는 tryptophan을 첨가하지 않고 배양한 경우보다 약 4배 높은 수준이었다. 이러한 결과로 볼 때 본 연구에 사용된 B. velezensis GH1-13 균주는 작물생육촉진 및 곰팡이 병 방제 측면의 복합기능 생물학적 제제로서 매우 유용할 것으로 판단된다.

• 한국환경농학회지
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• 제40권1호
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• pp.49-59
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• 2021

BACKGROUND: Soil salinity causes reduction of crop productivity. Rhizosphere microbes have metabolic capabilities and ability to adaptation of plants to biotic and abiotic stresses. Plant growth-promoting bacteria (PGPB) could play a role as elicitors for inducing tolerance to stresses in plants by affecting resident microorganism in soil. This study was conducted to demonstrate the effect of selected strains on rhizosphere microbial community under salinity stress. METHODS AND RESULTS: The experiments were conducted in tomato plants in pots containing field soil. Bacterial suspension was inoculated into three-week-old tomato plants, one week after inoculation, and -1,000 kPa-balanced salinity stress was imposed. The physiological and biochemical attributes of plant under salt stress were monitored by evaluating pigment, malondialdehyde (MDA), proline, soil pH, electrical conductivity (EC) and ion concentrations. To demonstrate the effect of selected Bacillus strains on rhizosphere microbial community, soil microbial diversity and abundance were evaluated with Illumina MiSeq sequencing, and primer sets of 341F/805R and ITS3/ITS4 were used for bacterial and fungal communities, respectively. As a result, when the bacterial strains were inoculated and then salinity stress was imposed, the inoculation decreases the stress susceptibility including reduction in lipid peroxidation, enhanced pigmentation and proline accumulation which subsequently resulted in better plant growth. However, bacterial inoculations did not affect diversity (observed OTUs, ACE, Chao1 and Shannon) and structure (principle coordinate analysis) of microbial communities under salinity stress. Furthermore, relative abundance in microbial communities had no significant difference between bacterial treated- and untreated-soils under salinity stress. CONCLUSION: Inoculation of Bacillus strains could affect plant responses and soil pH of tomato plants under salinity stress, whereas microbial diversity and abundance had no significant difference by the bacterial treatments. These findings demonstrated that Bacillus strains could alleviate plant's salinity damages by regulating pigments, proline, and MDA contents without significant changes of microbial community in tomato plants, and can be used as effective biostimulators against salinity stress for sustainable agriculture.