• Mycobiology
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• v.28 no.4
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• pp.185-189
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• 2000

The antifungal activity of methanolic extracts of Centella asiatica and Andrographis paniculata leaves was observed against fourteen fungi, viz., Alternaria alternata, A. brassicae, A. brassicicola, A. solani, A. tenuissima, Cercospora blumae, Curvularia lunata, C. penniseti, and Drechslera monoceras, D. oryzae, D. turitica, Fusarium albizziae and F. udum. Different concentrations of the methanolic extract (1000, 2000, 3000, 5000, 7000, 10000ppm) were used. The effect of mixed leaf extract (1500 ppm of C. asiatica + 1500 ppm of A. paniculata) and its 1:2 ad 1:4 dilutions were also studied. The individual extracts of both the plants showed significant inhibitory effect on spore germination of all the fungi tested. F. udum, F. albizzae, D. oryzae, D. turtica, and D. monoceras were particularly sensitive to these extracts. In general, the extract of C. asiatica showed a higher inhibitory effect in all concentrations against all the fungi as compared to A. paniculata, except for A. brassicae A. solani, D. oryzae, D. penniseti and Curvularia sp. The inhibitory effect of extracts increased when they were used in combination with or without dilutions against A. brassicicola, A. solani A. brassicae, A. alternata, A. tenussima, C. blumae, C. lunata, C. penniseti and Curvularia species. Higher efficacy of active ingredient of these extracts under field condition is envisaged against plant pathogens.

• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.57-62
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• 1997

This experiment was conducted to test the control effect of methanol extracts of 10 medicinal plants on apple storage diseases caused by Botryosphaeria berengeriana, Glomerella cingulata and Penicillium expansum. Out of the 10 medicinal plants, methanol extracts of Coptis japonica and Anemarrhena asphodeloides inhibited effectively the mycelial growth of B. berengeriana, G. cingulata and P. expansum in vitro, for which the inhibition ratios of the two plant extracts were 100.0% and 89.3%, 73.7% and 94.1%, and 100.0% and 51.6%, respectively. Spore germination of the three fungi was inhibited 100% only by C. japonica extract, but only P. expansum was inhibited 100% by A. asphodeloides extract. No lesion was formed y the fungi at 5$^{\circ}C$ up to 2 weeks after inoculation. Lesion sizes produced by the three fungi at the temperature ranges of 1$0^{\circ}C$ to $25^{\circ}C$ and infection of B. berengeriana and G. cingulata were inhibited by C. japonica extract, but not by A. asphodeloides extract, while no lesion was formed by the fungi at 5$^{\circ}C$. Infections of the fungi on apples were somewhat stimulated by A. asphodeloides extract.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.80-85
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• 2008

This study was carried out to assess the antidermatophytic potential of the ethyl acetate(EtOAc) extract of the marine isolate of Aspergillus sp.. The fungus was isolated by serial dilution, and was identified Aspergillus sp.. The EtOAc extract of the fungus was examined to evaluate the antidermatophytic efficacy against the fungal pathogens infecting human skin using the disc diffusion and MIC(minimum inhibitory concentration) determination methods. The EtOAc extract($5{\mu}l\;disc^{-1}$) was considered to have the antidermatophytic activity based on the inhibition percentage of the mycelial growth of the fungi tested such as Trichophyton mentagrophytes KCTC 6085, Microsporum canis KCTC 6591, Microsporum canis KCTC 6348, Trichophyton rubrum KCTC 6352, Microsporum canis KCTC 6349 and Trichophyton mentagrophytes KCTC 6316. The percentage of the inhibition ranged from 54% to 81, and the MIC obtained was 62.5, 62.5, 250, 125, 125, and $125{\mu}g\;ml^{-1}$, respectively. The extract had a strong detrimental effect on the spore germination of the tested skin infectious pathogens. These findings strongly support the role of the ethyl acetate extract as a potential antidermatophytic agent.

• Journal of Applied Biological Chemistry
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• v.57 no.2
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• pp.153-157
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• 2014

Plant-growth-promoting rhizobacteria can affect plant growth by various direct and indirect mechanisms. This study was conducted to determine the ability of some rhizobacterial strains to enhance the seed germination of Lactuca sativa (lettuce) and Raphanus sativus (radish). Seeds were inoculated using a spore suspension ($1{\times}10^7cfumL^{-1}$) and incubated in a growth chamber at $28^{\circ}C$ under dark conditions and 65% RH. Azotobacter chroococcum and LAP mix inoculation increased the plumule length of L. sativa by 1.3, 0.8, and 0.7 cm, respectively, in comparison to the uninoculated control. Pseudomonas putida showed an increase of only 0.6 cm in plumule length when compared to the control. Inoculation of A. chroococcum, P. putida, and LAP mix enhanced the seed germination rate of R. sativus, by 10, 5, and 30%, respectively, in comparison with the uninoculated seeds. The results demonstrated that the inoculation of seeds by select rhizobacterial strains showed remarkable enhancement to the radicle length of lettuce and radish seedlings.

• Research in Plant Disease
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• v.24 no.1
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• pp.33-40
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• 2018

This study was conducted to evaluate the antifungal activity of 19 agro-materials that have been registered for organic cultivation in Korea, after inoculation of pear leaves with Venturia nashicola and Gymnosporangium asiaticum. In V. nashicola, most of the nine agro- materials containing sulfur and copper completely inhibited spore germination, and some of the spores that germinated did not form appressoria. However, in only lime sulfur, Neobordeaux (cupric sulfate), and Wheengaris (sulfur)showed antifungal activity against G. asiaticum. Among the agro-materials containing plant extracts, Wheengarujaba (wood vinegar+spirits+rhubarb) inhibited conidial germination in V. nashicola and G. asiaticum by 100% and 71.6%, respectively. Among the agro-materials containing antifungal microorganisms, Cheongotan (Streptomyces griseus) reduced spore germination rate of V. nashicola to 88.8%; moreover, formation of appressoria or intracellular accumulation was not observed. Application of Topsid (Paenibacillus polymyxa) reduced spore germination rates in V. nashicola and G. asiaticum to 71.0% and 90.6%, respectively, and the formation of appressoria was not observed. Studying the antifungal activity of agro-materials because of cumulative applications under the field conditions is necessary, owing to their contact fungicidal effect and the induced-resistance by microbial metabolites and natural compounds.

• BMB Reports
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• v.42 no.1
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• pp.47-52
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• 2009

Alanine racemase catalyzes the interconversion of L-alanine and D-alanine and plays a crucial role in spore germination and cell wall biosynthesis. In this study, alanine racemase produced by Bacillus anthracis was expressed and purified as a monomer in Escherichia coli and the importance of lysine 41 in the cofactor binding octapeptide and tyrosine 270 in catalysis was evaluated. The native enzyme exhibited an apparent $K_m$ of 3 mM for L-alanine, and a $V_{max}$ of $295\;{\mu}moles/min/mg$, with the optimum activity occurring at $37^{\circ}C$ and a pH of 8-9. The activity observed in the absence of exogenous pyridoxal 5'-phosphate suggested that the cofactor is bound to the enzyme. Additionally, the UV-visible absorption spectra indicated that the activity was pH independece, of VV-visible absorption spectra suggests that the bound PLP exists as a protonated Schiff's base. Furthermore, the loss of activity observed in the apoenzyme suggested that bound PLP is required for catalysis. Finally, the enzyme followed non-competitive and mixed inhibition kinetics for hydroxylamine and propionate with a $K_i$of $160\;{\mu}M$ and 30 mM, respectively.

• The Korean Journal of Mycology
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• v.22 no.1
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• pp.36-45
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• 1994

Hyphal growth, auxiliary cell development and hyphal healing process of Gigaspora margarita, Scutellospora heterogama and S. verrucosa were investigated. The germinated hyphae from spores grew on the surface and the bottom of agar media. The hyphal growth on the surface stopped 19 to 23 days and the growth on the bottom 40 to 51 days after spore germination. Auxiliary cells began to develop 7 to 9 days after the spore germination in the media. The auxiliary cells almost always developed on the tip of a hypha branched from a secondary hypha. The cytoplasmic streaming rates in the hyphae of G. margarita and S. heterogama were $2.7\;to\;3.3\;{\mu}m/s\;and\;3.8\;to\;4.3\;{\mu}m/s$, respectively. The hyphae artificially cut were healed by connecting with a hypha grown from the spore-side hypha. We may suggest that the wound healing process of hyphae should be one of the characteristics obtained from symbiotic relationship between host plants and arbuscular mycorrhizal fungi for a long period of time.

• The Korean Journal of Mycology
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• v.22 no.1
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• pp.50-61
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• 1994

From soil samples, 380 antagonistic microorgnisms were isolated. Among the isolates, 42 strains had mycelia growing inhibition ability against Fusariun solani, ginseng root rot causing pathogen. Isolates CHA 1 and S-PFHR 6 were proposed as antagonists for this study and they were identified as Promicromonospora sp. and Pseudomonas pseudoalcaligenes respectively. As an antagonism against hyphae of F. solani in dual culture test, CHA 1 and S-PFHR 6 inhibited linear growing, caused abnormal branching, and the membrane projection which formed by cell wall destruction. The secondary metabolites contained in the culture filtrates which prepared from PD broth and Nutrient broth inhibited the spore germination to 14.3%. The culture filtrate of S-PFHR 6 which prepared by a little amount of soil extract addition to nutrient rich medium had more strongly. inhibited the spore germination and spore germination decreased to less than 4.0% in it. The soil used in this study had fungistasis and the germination rate of macroconidia and chlamydospore of F.solani was 19.4% and 17.7% respectively. The steam sterilized soil lost fungistasis and germination rate of conidia increased to more than 97.9%. The soils amended with the propagule of CHA 1 and S-PFHR 6 increased fungistasis and the germination rate of macroconidia decreased to 14.7% and 11.7% respectively in each treatments. But the soil ammended with glucose and asparagine annulled fungistatic ability and the germination rate of macroconidia increased to more than 48.0%. As an antagonistic activity of the secondary metabolites of two antagonistic isolates in soil, the germination rate of macroconidia of F. solani was 9.3% in the soil amended with the culture filtrate of CHA 1 but the culture filtrate of S-PFHR 6 had no such activity. In the soil which treated with antagonist propagule or culture filtrate, the chlamydospore germination rate was lower than that in natural soil. The addition of glucose and asparagine to antagonist propagule treated soil did not enhanced the chlamydospore germination.

• The Korean Journal of Mycology
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• v.9 no.3
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• pp.141-145
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• 1981

Germination of the single-basidiospore of Agaricus bisporus, mycelial characteristics of the single spore culture and its fruit body formation were studied. Germination of the single basidiospore was the best on water agar. Of 6372 spores isolated, 1622 spore were germinated and the germination rate was 26 percent. Cultures from single basidiospores showed two distinct mycelial types on the compost extract sucrose agar: one was the strandy type and the other was the fluffy. The strandy type culture produced more sporophores than the fluffy. Of 778 strandy isolates screened, nine cultures yielded 5 percent higher than the origine. No. 1567 and 1708 were selected for the commercial cultivation.

• Korean journal of applied entomology
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• v.20 no.1 s.46
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• pp.1-5
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• 1981

Effect of crude saponin and raw ginseng juice on root rot pathogens such as Fusarium solani and Erwinia carotovora for there growth or spore germination was investigated. Macroconidial germination of F. solani was decreased as the incrasee of the crude saponin concentration. especially, percentage of the germination was remarkably reduced when the concentration was more than 500ppm. The spore production of F. solani was also reduced as the increase of the crude saponin concentration and this phenomenon was particularly profound on a solid medium. Mycelial growth was decreased when the crude saponin was added, while the effect of the concentration was not apparently significant. The higher concentration of raw ginseng juice is, the more the growth of F. solani. Growth of E. carotovora was enhanced by crude ginseng saponin and raw ginseng juice. The crude ginseng saponin stimulated the growth of E. carotovora as the increase of the concentration, while more growth of the bacteria obtained at $1\%$ raw ginseng juice added.