• Title/Summary/Keyword: Inhibition of fungal growth

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Biological Control of Anthracnose (Colletotrichum gloeosporioides) in Red Pepper by Bacillus sp. CS-52 (Bacillus sp. CS-52를 이용한 고추 탄저병 (Colletotrichum gloeosporioides) 방제 특성)

  • Kwon, Joung-Ja;Lee, Jung-Bok;Kim, Beam-Soo;Lee, Eun-Ho;Kang, Kyeong-Muk;Shim, Jang-Sub;Joo, Woo-Hong;Jeon, Chun-Pyo;Kwon, Gi-Seok
    • Korean Journal of Microbiology
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    • v.50 no.3
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    • pp.201-209
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    • 2014
  • This study was carried out in order to develop a biological control of anthracnose of red pepper caused by fungal pathogens. In particular, this study focuses on the Colletotrichum species, which includes important fungal pathogens causing a great deal of damage to red pepper. Antagonistic bacteria were isolated from the soil of pepper fields, which were then tested for biocontrol activity against the Colletotrichum gloeosporioides anthracnose pathogen of pepper. Based on the 16S rRNA sequence analysis, the isolated bacterial strain CS-52 was identical to Bacillus sp. The culture broth of Bacillus sp. CS-52 had antifungal activity toward the hyphae and spores of C. gloeosporioides. Moreover, the substances with antifungal activity were optimized when Bacillus sp. CS-52 was grown aerobically in a medium composed of 0.5% glucose, 0.7% $K_2HPO_4$, 0.2% $KH_2PO_4$, 0.3% $NH_4NO_3$, 0.01% $MnSO_4{\cdot}7H_2O$, and 0.15% yeast extract at $30^{\circ}C$. The inhibition of spore formation resulting from cellulase, siderophores, and indole-3-acetic acid (IAA), were produced at 24 h, 48 h, and 72 h, respectively. Bacillus sp. CS-52 also exhibited its potent fungicidal activity against anthracnose in an in vivo test, at a level of 70% when compared to chemical fungicides. These results identified substances with antifungal activity produced by Bacillus sp. CS-52 for the biological control of major plant pathogens in red pepper. Further studies will investigate the synergistic effect promoting better growth and antifungal activity by the formulation of substances with antifungal activity.

Introduction and Expression of PAP gene using Agrobacterium in Scrophularia buergeriana Miquel (Agrobacterium을 이용한 PAP 유전자의 현삼으로 도입 및 형질발현)

  • Yu, Chang-Yeon;Seong, Eun-Soo;Lim, Jung-Dae;Huang, Shan-Ai;Chae, Young-Am
    • Korean Journal of Medicinal Crop Science
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    • v.9 no.2
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    • pp.156-165
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    • 2001
  • Exogeneous application of pokeweed antiviral protein (PAP), a ribosomal-inacivating protein in the cell wall of Phytolacca americana (pokeweed) protects heterologous plants from viral and fungal infection. A cDNA clone of PAP introduced into Scrophularia buergeriana Miquel by thransformation with Agrobacterium tumefaciences. For plant transformation, explants were precultured on shoot induction medium without kanamycin for 2-5 day, and then they were cocultured with Agrobacterium for 10 minutes. The explants were placed on co culture medium in dark condition, $28^{\circ}C$ for 2days. After explants were washed in MS liquid medium, they were transferred into selection medium including kanamycin 50mg/L (MS salts+1mg/ l BAP+2mg/ l TDZ+0,2mg/ l NAA+MS vitamin+3% sucrose+0.8% agar, pH5.8). From PCR analysis, NPT II band was confirmed in transgenic plant genome and showed resistance against fungi in antifungal activity test. Micro assay to which protein extracted from transgenic line were added, revealed hyphae growth inhibition and no spore germination at high concentration. The characteristics of inhibited hyphae was represented transparent and thin. Expression of PAP in transgenic plants offers the possibility of developing resistance to viral and fungal infection.

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Antifungal Activity of Bacillus sp. AM-651 Against Phytophthora capsici (고추역병 유발병원균 Phytophthora capsici에 대한 Bacillus sp. AM-651의 항진균활성)

  • Lee, Jung-Bok;Shin, Jeong-Hak;Jang, Jong-Ok;Shin, Kee-Sun;Choi, Chung-Sik;Kim, Kun-Woo;Jo, Min-Sub;Jeon, Chun-Pyo;Kim, Yun-Hoi;Kwon, Gi-Seok
    • Microbiology and Biotechnology Letters
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    • v.36 no.3
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    • pp.227-232
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    • 2008
  • Biological antagonists of Phytophthora capsici were isolated from soil in Gyeongbuk, Korea. Among the isolated bacteria, a Bacillus sp. was identified from l6S rDNA sequence analysis and named Bacillus sp. AM-651. Bacillus sp. AM-65l strain which can strongly a antifungal activity against Phytophthora capsici. Culture conditions for the maximum production of the antagonistic substance were optimized. The production of antibiotic were high on modified Davis mineral medium pH 7 at $30^{\circ}C$. The medium for highest production of the agonistic substance optimized. It is composed the best activity on glucose, $(NH_4)_2SO_4$ and $K_2HPO_4$ at 0.5%, 0.1%, and 0.7%, respectively. By time course of culture solution selected Bacillus sp. AM-65l, the culture solution after 48hrs had strongly growth inhibition rate against P. capsici. And culture solution of Bacillus sp. AM-651 was stable within a pH range $5{\sim}11$ and temperature range $4{\sim}70^{\circ}C$. Bacillus sp. AM-651 cultured broth shown fungal growth inhibitory activity against B. sorokiniana, B. cinerea, R. solani avove and beyond P. capsici and comparatively showed a high activity against C. gloeosporioides, B. dothidea, B. cinerea and F. graminearum by agar diffusion method.

Food Waste Composting by Using an Inoculum-Mixture Containing New Facultative Anaerobic Bacteria (신규 통성혐기성 세균으로 제조한 발효흙에 의한 음식물 쓰레기의 퇴비화)

  • Hwang, Kyo-Yeol;Lee, Jae-Yeon;Kim, Keun;Sung, Su-Il;Han, Sung-Ho
    • Journal of the Korea Organic Resources Recycling Association
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    • v.9 no.1
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    • pp.65-72
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    • 2001
  • Four newly isolated bacteria from soil were used to manufacture microbial inoculum to compost food waste. The bacteria, GM103, V25, V31, and V35, were identified as Bacillus licheniformis, B. subtilis, B. stearothermophilius, and B, subtilis, respectively. The bacterial strains were efficient to degrade protein and starch and also able to inhibit the growth of plant pathogenic fungus Rhizopus stronifer. The GM103 showed distinct capability in degrading starch, but grow only aerobically. The other three bacterial strains. V25, V31, and V35, could grow both aerobically as well as anaerobically, in 10%(w/v) salt, at $50^{\circ}C$, and had good viability and survival rate in soil. These characteristics of the bacterial strains are very adquate in Korean food composting containing high concentration of salt, especially at home. By mixing the 4 bacterial culture broth with molasses, beet pulp, zeolite, The bacterial inoculum for food waste composting-BIOTOP-CLEAN-was made. The performance of food waste composting by the BIOTOP-CLEAN was compared with that by control(not treated) and HS(other demestic company's inoculum product for food waste composting). The maximum temperature of the food waste during the composting with the BIOTOP-CLEAN was $50^{\circ}C$, while those of the control and HS were $30^{\circ}C$ and $35^{\circ}C$, respectively. The BIOTOP-CLEAN gave the good smell and showed dark brown color, while the control gave bad smell and HS gave less bad smell. These indicates that the food waste composting by the BIOTOP-CLEAN had been well accomplished. The culture broth of V25, V31, V35 were sparyed to the plants of tomato, chinese cabbage, raddish, red pepper every month and the spraying the culture broth to these plant significantly improved the production yield of the crops, due to the control effect of the bacterial strains against the plant pathogens.

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Assessment of Bio-corrosive Effect and Determination of Controlling Targets among Microflora for Application of Multi-functional CFB on Cement Structure (다기능 탄산칼슘 형성세균의 시멘트 건축물 적용위한 부식능 평가 및 건축물 정주미생물 중 방제 대상 결정)

  • Park, Jong-Myong;Park, Sung-Jin;Ghim, Sa-Youl
    • Journal of Life Science
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    • v.25 no.2
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    • pp.237-242
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    • 2015
  • The use of calcite-forming bacteria (CFB) in crack remediation and durability improvements in construction materials creates a permanent and environmentally-friendly material. Therefore, research into this type of application is stimulating interdisciplinary studies between microbiology and architectural engineering. However, the mechanisms giving rise to these materials are dependent on calcite precipitation by the metabolism of the CFB, which raises concerns about possible hazards to cement-based construction due to microbial metabolic acid production. The aim of this study was to determine target microorganisms that possibly can have bio-corrosive effects on cement mortar and to assess multi-functional CFBs for their safe application to cement structures. The chalky test was first used to evaluate the $CaCO_3$ solubilization feature of construction sites by fungi, yeast, bacterial strains. Not all bacterial strains are able to solubilize $CaCO_3$, but C. sphaerospermum KNUC253 or P. prolifica KNUC263 showed $CaCO_3$ solubilization activity. Therefore, these two strains were identified as target microorganisms that require control in cement structures. The registered patented strains Bacillus aryabhatti KNUC205, Arthrobacter nicotianae KNUC2100, B. thuringiensis KNUC2103 and Stenotrophomonas maltophilia KNUC2106, reported as multifunctional CFB (fungal growth inhibition, crack remediation, and water permeability reduction of cement surfaces) and isolated from Dokdo or construction site were unable to solubilize $CaCO_3$. Notably, B. aryabhatti KNUC205 and A. nicotianae KNUC2100 could not hydrolyze cellulose or protein, which can be the major constituent macromolecules of internal materials for buildings. These results show that several reported multi-functional CFB can be applied to cement structures or diverse building environments without corrosive or bio-deteriorative risks.

Brief Introduction of Research Progresses in Control and Biocontrol of Clubroot Disease in China

  • He, Yueqiu;Wu, Yixin;He, Pengfei;Li, Xinyu
    • 한국균학회소식:학술대회논문집
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    • 2015.05a
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    • pp.45-46
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    • 2015
  • Clubroot disease of crucifers has occurred since 1957. It has spread to the whole China, especially in the southwest and nourtheast where it causes 30-80% loss in some fields. The disease has being expanded in the recent years as seeds are imported and the floating seedling system practices. For its effective control, the Ministry of Agriculture of China set up a program in 2010 and a research team led by Dr. Yueqiu HE, Yunnan Agricultural University. The team includes 20 main reseachers of 11 universities and 5 institutions. After 5 years, the team has made a lot of progresses in disease occurrence regulation, resources collection, resistance identification and breeding, biological agent exploration, formulation, chemicals evaluation, and control strategy. About 1200 collections of local and commercial crucifers were identified in the field and by artificiall inoculation in the laboratories, 10 resistant cultivars were breeded including 7 Chinese cabbages and 3 cabbages. More than 800 antagostic strains were isolated including bacteria, stretomyces and fungi. Around 100 chemicals were evaluated in the field and greenhouse based on its control effect, among them, 6 showed high control effect, especially fluazinam and cyazofamid could control about 80% the disease. However, fluzinam has negative effect on soil microbes. Clubroot disease could not be controlled by bioagents and chemicals once when the pathogen Plasmodiophora brassicae infected its hosts and set up the parasitic relationship. We found the earlier the pathogent infected its host, the severer the disease was. Therefore, early control was the most effective. For Chinese cabbage, all controlling measures should be taken in the early 30 days because the new infection could not cause severe symptom after 30 days of seeding. For example, a biocontrol agent, Bacillus subtilis Strain XF-1 could control the disease 70%-85% averagely when it mixed with seedling substrate and was drenching 3 times after transplanting, i.e. immediately, 7 days, 14 days. XF-1 has been deeply researched in control mechanisms, its genome, and development and application of biocontrol formulate. It could produce antagonistic protein, enzyme, antibiotics and IAA, which promoted rhizogenesis and growth. Its The genome was sequenced by Illumina/Solexa Genome Analyzer to assembled into 20 scaffolds then the gaps between scaffolds were filled by long fragment PCR amplification to obtain complet genmone with 4,061,186 bp in size. The whole genome was found to have 43.8% GC, 108 tandem repeats with an average of 2.65 copies and 84 transposons. The CDSs were predicted as 3,853 in which 112 CDSs were predicted to secondary metabolite biosynthesis, transport and catabolism. Among those, five NRPS/PKS giant gene clusters being responsible for the biosynthesis of polyketide (pksABCDEFHJLMNRS in size 72.9 kb), surfactin(srfABCD, 26.148 kb, bacilysin(bacABCDE 5.903 kb), bacillibactin(dhbABCEF, 11.774 kb) and fengycin(ppsABCDE, 37.799 kb) have high homolgous to fuction confirmed biosynthesis gene in other strain. Moreover, there are many of key regulatory genes for secondary metabolites from XF-1, such as comABPQKX Z, degQ, sfp, yczE, degU, ycxABCD and ywfG. were also predicted. Therefore, XF-1 has potential of biosynthesis for secondary metabolites surfactin, fengycin, bacillibactin, bacilysin and Bacillaene. Thirty two compounds were detected from cell extracts of XF-1 by MALDI-TOF-MS, including one Macrolactin (m/z 441.06), two fusaricidin (m/z 850.493 and 968.515), one circulocin (m/z 852.509), nine surfactin (m/z 1044.656~1102.652), five iturin (m/z 1096.631~1150.57) and forty fengycin (m/z 1449.79~1543.805). The top three compositions types (contening 56.67% of total extract) are surfactin, iturin and fengycin, in which the most abundant is the surfactin type composition 30.37% of total extract and in second place is the fengycin with 23.28% content with rich diversity of chemical structure, and the smallest one is the iturin with 3.02% content. Moreover, the same main compositions were detected in Bacillus sp.355 which is also a good effects biocontol bacterial for controlling the clubroot of crucifer. Wherefore those compounds surfactin, iturin and fengycin maybe the main active compositions of XF-1 against P. brassicae. Twenty one fengycin type compounds were evaluate by LC-ESI-MS/MS with antifungal activities, including fengycin A $C_{16{\sim}C19}$, fengycin B $C_{14{\sim}C17}$, fengycin C $C_{15{\sim}C18}$, fengycin D $C_{15{\sim}C18}$ and fengycin S $C_{15{\sim}C18}$. Furthermore, one novel compound was identified as Dehydroxyfengycin $C_{17}$ according its MS, 1D and 2D NMR spectral data, which molecular weight is 1488.8480 Da and formula $C_{75}H_{116}N_{12}O_{19}$. The fengycin type compounds (FTCPs $250{\mu}g/mL$) were used to treat the resting spores of P. brassicae ($10^7/mL$) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm (A260) and at 280 nm (A280) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be lyzed by the FTCPs of XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol. In the five selected medium MOLP, PSA, LB, Landy and LD, the most suitable for growth of strain medium is MOLP, and the least for strains longevity is the Landy sucrose medium. However, the lipopeptide highest yield is in Landy sucrose medium. The lipopeptides in five medium were analyzed with HPLC, and the results showed that lipopeptides component were same, while their contents from B. subtilis XF-1 fermented in five medium were different. We found that it is the lipopeptides content but ingredients of XF-1 could be impacted by medium and lacking of nutrition seems promoting lipopeptides secretion from XF-1. The volatile components with inhibition fungal Cylindrocarpon spp. activity which were collect in sealed vesel were detected with metheds of HS-SPME-GC-MS in eight biocontrol Bacillus species and four positive mutant strains of XF-1 mutagenized with chemical mutagens, respectively. They have same main volatile components including pyrazine, aldehydes, oxazolidinone and sulfide which are composed of 91.62% in XF-1, in which, the most abundant is the pyrazine type composition with 47.03%, and in second place is the aldehydes with 23.84%, and the third place is oxazolidinone with 15.68%, and the smallest ones is the sulfide with 5.07%.

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