• Journal of Microbiology and Biotechnology
• /
• 제30권2호
• /
• pp.226-236
• /
• 2020

Antibiotic resistance by pathogenic bacteria and fungi is one of the most serious global public health problems in the 21^st century, directly affecting human health and lifestyle. Pseudomonas aeruginosa and Staphylococcus aureus with strong resistance to the common antibiotics have been isolated from Intensive Care Unit patients at Zagazig Hospital. Thus, in this study we assessed the biocidal activity of nanoparticles of silver, copper and zinc synthesized by Fusarium solani KJ 623702 against these multidrug resistant-bacteria. The synthesized Metal Nano-particles (MNPs) were characterized by UV-Vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and Zeta potential. The Fourier transform infrared spectroscopy (FTIR) result showed the presence of different functional groups such as carboxyl, amino and thiol, ester and peptide bonds in addition to glycosidic bonds that might stabilize the dispersity of MNPs from aggregation. The antimicrobial potential of MNPs by F. solani against the multidrug-resistant (MDR) P. aeruginosa and S. aureus in addition to the mycotoxigenic Aspergillus awamori, A. fumigatus and F. oxysporum was investigated, based on the visual growth by diameter of inhibition zone. Among the synthesized MNPs, the spherical AgNPs (13.70 nm) displayed significant effect against P. aeruginosa (Zone of Inhibition 22.4 mm and Minimum Inhibitory Concentration 21.33 ㎍/ml), while ZINC oxide Nano-Particles were the most effective against F. oxysporum (ZOI, 18.5 mm and MIC 24.7 ㎍/ml). Transmission Electron Microscope micrographs of AgNP-treated P. aeruginosa showed cracks and pits in the cell wall, with internalization of NPs. Production of pyocyanin pigment was significantly inhibited by AgNPs in a concentration-dependent manner, and at 5-20 ㎍ of AgNPs/ml, the pigment production was reduced by about 15-100%, respectively.

• 한국미생물·생명공학회지
• /
• 제19권4호
• /
• pp.356-361
• /
• 1991

식물근부병의 방제균으로 선발된 Bacillus subtilis YBL-7의 식물부균 Fusarium solani에 대한 길항력을 유전공학적 조작에 의해 다목적으로 증강시킬 수 있는지를 타진하기 위해 외부유전자인 Bacillus pasteurii의 urease 유전자를 생물방제균 B.subtilis YBL-7내 도입자하고자 시도하였다. 외부 urease 유전자는 B.pasteurii의 urease gene을 shuttle vector인 pGR71의 HindII site에 삽입하여 E.coli내에서 발현시킨 pGU66을 사용하여 형질전환시켰으며 이때의 최적 형질전환조건과 도입된 urease 유전자의 발현을 조사해 보았다.

• Mycobiology
• /
• 제30권1호
• /
• pp.51-54
• /
• 2002

This paper deals with the study on comparative efficacy and in vitro activity of cow urine and cow dung for controlling root rot disease of cucumber caused by Fusarium solani f. sp. cucurbitae Snyder & Hansen following slide germination and mycelial growth inhibition tests. Results showed that both germination of conidia and the percentage inhibition of mycelial growth decreased or suppressed and varied greatly with respect to different hour and days of incubation and kind of bio-matters. In between two bio-matters cow urine was found more effective than that of cow dung in conidial germination. No germination of conidia was recorded after one hour of incubation in any medium whereas in cow urine germination of conidia was not also observed even after 2 hours of incubation. After 7 hours of incubation out of 200 conidia of F. solani f. sp. cucurbitae, 28 in cow urine and 64 in cow dung were germinated while in control a total germinated conidia was 185. In case of percentage inhibition of conidial germination the highest percentage(100%) was recorded in cow urine after 2 hours of incubation followed by 3 hours(96.0%), 4 hours(91.0%) and 6 hours(89.4%). During the test on inhibition of mycelial growth, the highest percentage(62.8%) was recorded in cow urine potato dextrose agar(CUPDA) medium tested after 4 days of incubation, followed by 3 days(60.5%), 5 days(56.5%) and 2 days(55.0%). In this test cow dung potato dextrose agar(CDPDA) had less efficacy in suppression of the percentage inhibition of mycelial growth.

• Journal of Ginseng Research
• /
• 제44권1호
• /
• pp.161-167
• /
• 2020

Background: The ascomycete fungi Cylindrocarpon destructans (Cd) and Fusarium solani (Fs) cause ginseng root rot and significantly reduce the quality and yield of ginseng. Cd produces the secondary metabolite radicicol, which targets the molecular chaperone Hsp90. Fs is resistant to radicicol, whereas other fungal genera associated with ginseng disease are sensitive to it. Radicicol resistance mechanisms have not yet been elucidated. Methods: Transcriptome analyses of Fs and Cd mycelia treated with or without radicicol were conducted using RNA-seq. All of the differentially expressed genes (DEGs) were functionally annotated using the Fusarium graminearum transcript database. In addition, deletions of two transporter genes identified by RNA-seq were created to confirm their contributions to radicicol resistance. Results: Treatment with radicicol resulted in upregulation of chitin synthase and cell wall integrity genes in Fs and upregulation of nicotinamide adenine dinucleotide dehydrogenase and sugar transporter genes in Cd. Genes encoding an ATP-binding cassette transporter, an aflatoxin efflux pump, ammonium permease 1 (mep1), and nitrilase were differentially expressed in both Fs and Cd. Among these four genes, only the ABC transporter was upregulated in both Fs and Cd. The aflatoxin efflux pump and mep1 were upregulated in Cd, but downregulated in Fs, whereas nitrilase was downregulated in both Fs and Cd. Conclusion: The transcriptome analyses suggested radicicol resistance pathways, and deletions of the transporter genes indicated that they contribute to radicicol resistance.

• 한국환경농학회지
• /
• 제20권1호
• /
• pp.57-62
• /
• 2001

여러 작물 재배지 토양에서 각종 근권미생물을 분리하여 이들 분리미생물 중 수박 만할병균인 Fusarium oxysporum f. sp. niveum(KCCM34741)에 길항하는 미생물인 YJ-19, YJ-45, YJ-3 등 12 균주를 분리하였다. 길항미생물들은 MS agar 배지 실험 및 미생물제제 첨가 상토 실험에서 모두 참박의 발아율을 향상시켰으며, 이들 중 분리주 YJ-3 균주는 참박의 발아율과 초기생육에 가장 큰 영향을 주는 미생물로 선별되었다. YJ-3 균주를 제제화하여 참박 재배 기간별로 식물체 생육실험을 행한 결과 대조구인 일반 상토 및 시판 미생물혼합 상토 보다 각각 46%와 13%정도 생육을 촉진하는 것으로 나타났다. 분리주 YJ-3 균주는 간균의 gram 양성균으로서 Bacillus sp.로 동정되었다. Bacillus sp. YJ-3은 수박 만할병균인 F. oxysporum f. sp. niveum에 대해 강한 억제효과를 나타내었고, 그외 수박 병원균인 Alternaria cucumerina, Botrytis cinerea, Colletotrichum orbiculare, Didymella bryoniae, Rhazoctonia solani 등에서도 우수한 길항력을 나타내어 본 Bacillus sp. YJ-3 균주는 수박 만할병균에 길항하는 동시에 참박의 생육을 촉진하는 미생물로 확인되었다.

• 생명과학회지
• /
• 제12권2호
• /
• pp.200-207
• /
• 2002

채소류 모잘록병균인 Pythium ultimun에 길항하는 미생물을 분리하기 위해 체소류 뿌리를 균원시료로 하여 약600여종의 근권미생물을 분리하였고, 그중 5종의 근권미생물이 길항력을 나타내어 가장 높은 길항력 높은 Yl-37 균주를 최종 선별하였다. 분리한 길항균 YJ-37을 Bergey's Mannual of Systematic Bacteriology의 방법에 준하여 미생물의 형태학적, 배양학적, 생리·생화학적 특성을 조사 하였으며, 미생물의 세포벽의 지방산의 조성으로 자동 동정하는 Sherlock system을 이용하는 방법과 16S rDNA의 부분염기서열을 결정하여 동정하는 방법 등 3가지 방법으로 조사한 결과, 근권 길항미생물인 YJ-37 균주는 Bacillus ehimensis로 동정되었다. 채소류 모잘록병균 Pythium ultimun과 Rhizoctonia solani AG-4 이외에도 B. ehimensis YJ-37에 의한 병원성 진균의 길항력을 조사한 결과, Alternaria altrata, Collectotrichum gloeosporioides, Didymella bryoniae, Fu-sarium moniliforme, F oxysporum, F. oxysporum cucumerinum, F. oxysporum niveum, Gloeosporium sp., Glomerella sp., G. cingulata, G. lagenaria, Penicillium digitatum, P. itazicum, Phytophthora capsici, Sclerotinia sclerotiorum, Stemprhyzium solani등 대부분의 병원균에 대해서 항진균 활성을 나타내었다.

• 한국미생물·생명공학회지
• /
• 제25권1호
• /
• pp.62-67
• /
• 1997

A potential biocontrol bacterium, YB-70 was isolated from a rhizosphere in suppressive soil and identified as a strain of Bacillus subtilis. In several biochemical and in vitro antibiosis tests on Fusarium solani with the culture filterates from B. subtilis YB-70, we found that antifungal mechanism of B. subtilis YB-70 was mediated by antibiotic substances produced from the bacterium. These antifungal substances were appeared to be hear-resistant, micromolecular, and ethy alcohol soluble. Antifungal agents produced by B. subtilis YB-70 showed strong inhibified against root-rotting fungi F. solani in in vivo pot test. An antifungal substance. YBS-1s, was purified from the culture broth of B. subtilis YB-70 by isoelectronic precipitation, silica gel column chromatography and Sephadex LH-20 column chromatography analysis by Fab-MASS, $^{1}$H-NMR, $^{13}$C-NMR, DEPT, and amino acid analyzer revealed that the YBS-1A was a peptide antibiotics of iturin class containing seven amino acids from five different groups, and the other(YBS-1B) was an analogue of iturin group composed of 11 amino acids with larher molecular weight of about 1, 500 dalton, which was lager than that of iturin A.

• Journal of Applied Biological Chemistry
• /
• 제56권4호
• /
• pp.199-204
• /
• 2013

The nematicidal, antifungal and antioxidant activities of methanol extracts from six Vietnamese native medicinal plants were evaluated by various assays in vitro. Of the plant extracts tested, Terminalia nigrovenulosa was found to possess the highest activity when compared to the others. The leaves and bark of T. nigrovenulosa showed strong inhibitory activity against Meloidogyne incognita and Fusarium solani. The DPPH (1,1-Diphenyl-2-picryl-hydrazyl) radical scavenging, reducing power and total antioxidant activities of T. nigrovenulosa bark were higher than that of the remainder plant extracts. Chitinase activity of these plants was also investigated using SDS-PAGE. The results obtained in the present study indicate that T. nigrovenulosa leaf extracts are the greatest potential source as nematicides and fungicides for the control of M. incognita and F. solani. In particularly, T. nigrovenulosa bark extracts could be used as a potential source of commercially viable levels of natural antioxidant.

• The Plant Pathology Journal
• /
• 제40권2호
• /
• pp.192-204
• /
• 2024

In this study, the efficacy of the essential oil of Mentha longifolia, Achillea arabica and Artemisia absinthium plants were evaluated against important soil-borne fungal pathogens as Verticillium dahliae, Rhizoctonia solani, and Fusarium oxysporum. Essential oils were obtained from plants by hydrodistillation method and the chemical components of essential oils were determined by analyzing by gas chromatography-mass spectrometry. The main components found as piperitone oxide (13.61%), piperitenone oxide (15.55%), pulegone (12.47%), 1-menthone (5.75%), and camphor (5.75%) in M. longifolia, á-selinene 13.38%, camphor 13.34%, L-4-terpineneol 8.40%, (-)-á-Elemene 7.01%, 1,8-cineole 4.71%, and (-)-spathulenol 3.84% in A. arabica, and á-thujone (34.64%), 1,8-cineole (19.54%), pulegone (7.86%), camphene (5.31%), sabinene (4.86%), and germacrene-d (3.67%) in A. absinthium. The antifungal activities of the oils were investigated 0.05, 0.1, 0.25, 0.5, 1.00, and 2.00 μl/ml concentrations with the contact effect method. M. longifolia oil (1.00 and 2.00 μl/ml) has displayed remarkable antifungal effect and provided 100% inhibition on mycelial growth of V. dahliae, R. solani and F. oxysporum. The results obtained from this study may contribute to the development of new alternative and safe methods against soil-borne fungal pathogens.

• Journal of Microbiology and Biotechnology
• /
• 제4권4호
• /
• pp.296-304
• /
• 1994

Antibiotic substances were produced by Bacillus subtilis YB-70, a potential biocontrol agent found to suppress root-rot of eggplant (Solanum melonggena L) caused by Fusarium solani, in a dextrose glutamate medium and isolated by isoelectric precipitation. Partial purification was performed by column chromatography on silica gel with two solvent systems: chloroform-methanol and methanol-chloroform-water as eluting solvents, This active fraction YBS-1 s contained antifungal activity were soluble in ethanol, methanol, and water, but were not soluble in other solvents including acetone, butanol, ethyl ether, dimethylformamide, propanol, and etc. High performance liquid chromatography and thin layer chromatographic separation of YBS-1s showed that they have been composed of three biological active bands that were named YBS-1A, -1B, and -1C. The substances were stable to heat and resistant to protease. YBS-1s were active against a wide range of plant pathogenic fungi but did not inhibit the growth of bacteria and yeasts. They were not only fungicidal but also fungistatic against chlamydospores of F. solani. The $ED_{50}$ values for the chlamydospore germination and the germ-tube growth of F. solani were $O.725\mu\textrm{m}/ml\;and\;O.562\mu\textrm{m}/ml$, respectively. Microscopic observations proved the substances restricted the growth of phytopathogenic fungus F. solani by spore burst followed by dissolving of its germ-tube, and caused abnormal hyphal swelling after application to chlamydospores or growing hyphae. Cultural filtrate of B; subtilis YB-70 also suppressed the development of root-rot of eggplant in pot tests.