• Journal of Life Science
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• v.14 no.2
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• pp.320-324
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• 2004

The objective of this study was investigate the characteristic of biosurfactant produced from the isolated strain. The strain was isolated from soil samples and identified as Bacillus sp. TBM 911-5 by physiological characteristics and the partial nucleotide sequence analysis of 16S rDNA. We measured the surface tension every 6 hours for 80 hours. The surface tension of the culture filtrate of Bacillus sp. TBM 911-5 was decreased to 29 mN/m. Biosurfactant concentration was determined by diluting the culture filtrate until the critical micelle concentration (CMC). The biosurfactant emulsified hydrocarbons, vegetable oil and crude oil. Using soybean oil as substrate, the maximum emulsification activity and stability was obtained from the biosurfactant. The biosurfactant produced from Bacillus sp. TBM 911-5 had strong properties as an emulsifying agent and an emulsion-stabilizing agent.

• Korean Journal of Plant Resources
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• v.35 no.2
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• pp.385-389
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• 2022

In this study, we measured the inhibitory activity of Pinus densiflora leaf (PDL) against excessive lipid accumulation in mouse preadipocyte, 3T3-L1 cells to investigate whether PDL exerts anti-obesity activity. Lipid accumulation and the protein level were measured using Oil red O staining assay and Western blot analysis, respectively. We observed that PDL inhibited excessive lipid accumulation and decreased the expression of CEBPα, PPARγ and perilipin-1 related to lipid accumulation in 3T3-L1 cells. Therefore, considering these results, PDL can be used as a potential agent for anti-obesity.

• Applied Biological Chemistry
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• v.44 no.2
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• pp.109-115
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• 2001

The foliar uptake of dimethomoiph induced by several nonionic surfactants was measured in order to study the correlations between the uptake rate of dimethomorph and the fungicidal activity to cucumber downy mildew. Dimethomorph was not absorbed in cucumber leaf in the absence of activator surfactant. And the curative effect of dimethomoiph WP to cucumber downy mildew was very low under the concentration of 250 ${\mu}g/ml$. But dimethomorph uptake was remarkably enhanced by addition of nonionic surfactants, such as polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, and polyoxyethylene stearyl ether. And the curative effect to cucumber downy mildew was enhanced with proportion to uptake rate of dimethomorph. The protective effect to cucumber downy mildew, however, tends to decrease with the increase of foliar uptake of dimethomorph. The uptake rate of dimethomorph to cucumber leaf was proportional to the content of polyoxyethylene cetyl ether in formulation, but was decreased with dilution.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.679-684
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• 2005

The objective of this study was investigate the characteristic of biosurfactant produced from the iso-lated strain. The strain was isolated from soli samples of Duck-Yu Mountain and it was identified as Bacillus atrophaeus DYL-130 by 16S rDNA and gyrA gene nucleotide sequence analysis. The surface ten-sion of culture filtrate of Bacillus atrophaeus DYL-130 decreased to 28 mN/m and its biosurfactant con-centration was determined by diluting the culture filtrate until the critical micelle concentration (CMC). The emulsifying activity and stability of crude biosurfactant was measured by using water-immiscible hydrocarbons and oils as substrate. The biosurfactant was purified by affinity chromatography and the surface activity of purified biosurfactant was measured by drop-collapsing method and it could be effectively emulsify toluene.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.358-364
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• 1989

A crystalline alkaline pretense- producing Streptomyce sp. YSA-130 was isolated from soil in alkaline medium(pH 10.5). The optimum culture condition of Streptomyce sp. YSA-130 for the production of alkaline protease was as follows; 2.0% soluble starch, 1.0% soytone, 0.3% $K_2$HPO$_4$, 0.02% MgSO$_4$.7$H_2O$, 0.8% Na$_2$CO$_3$, pH 10.5, 3$0^{\circ}C$, and 12 hr. The alkaline pretense from the culture broth of Streptomyce sp. YSA-130 was purified about 24 folds by ammonium sulfate precipitation , dialysis, DEAE-cellulose ion exchange chromatography, gel filtration on Sephadex G-15 and crystallization. Optimum temperature and pH of purified enzyme were 6$0^{\circ}C$, and 11.5. Temperature and pH stability of purified enzyme were 5$0^{\circ}C$, and 5.5-12.0. Calcium ion was effective to stabilize the enzyme at higher temperature. The molecular weight of the purified enzyme was approximately 30,000. The purified enzyme was inactivated by diisopropyl flurophosphate(DFP) but not affected by metal ion, EDTA, sulfhydryl reagent and stable detergent.

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.272-279
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• 2010

KNF-1002, a new fungicide candidate, is very effective for protecting crops against plant diseases, but its curative activity against barley powdery mildew is negligible due to its weak penetrability into plant leaf. To select the most efficient activator and, at the same time, spreade-sticker, foliar uptake and deposit of aqueous spray formulations containing non-ionic or anionic surfactants and fatty acid alkyl esters as an adjuvant were assessed by using Congo Red method. In the absence of activator, only 0.1% of the applied active ingredient was absorbed by barley leaves 24 h after spraying with an aqueous acetone containing KNF-1002 100 mg/L. But, non-ionic surfactants (500 mg/L), such as heptaethylene glycol monooctadecenyl ether (OE-7), dodecaethylene glycol monohexadecyl ether (CE-12), so facilitated KNF-1002 uptake that the uptake was increased up to 48.5%. To wheat plant, the addition of surfactants in spray solution of KNF-1002 also increased the foliar uptake and deposition of active ingredient, but its efficiency varied according to the kind of fatty alcohol moiety of polyoxyethylene surfactant. KNF-1002 formulations containing nonaethylene glycol monododecyl ether (LE-9) as an activator and spreader-sticker showed remarkable increases of fungicidal activity against barley powdery mildew.

• Research in Plant Disease
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• v.15 no.3
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• pp.222-229
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• 2009

A Pseudomonas strain SG3 producing biosurfactant and showing antifungal and insecticidal activities was isolated from agricultural soil severely contaminated with machine oils. The antagonistic bacterium inhibited mycelial growth of all of the tested fungal pathogens. The fermentation broth of SG3 also effectively suppressed the development of various plant diseases including rice blast, tomato gray mold, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose. An antifungal substance was isolated from the fermentation broth of SG3 by ethyl acetate partitioning, silica gel column chromatography and preparative HPLC under the guide of bioassay. The chemical structure of the antifungal substance was determined to be rhamnolipid B by mass and NMR spectral analyses. The antifungal biosurfactant showed a potent in vivo antifungal activity against gray mold and late blight on tomato plants. In addition, rhamnolipid B inhibited mycelial growth of B. cinerea causing tomato gray mold and zoospore germination and mycelial growth of P. infestans causing tomato late blight. Pseudomonas sp. SG3 producing rhamnolipid B could be used as a new biocontrol agent for the control of plant diseases occurring on tomato plants.

• The Korean Journal of Pesticide Science
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• v.5 no.2
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• pp.51-57
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• 2001

Controlling effect of several surfactants on barley powdery mildew (pathogen : Erysiphae graminis) and those influence on fungicidal activity by tank-mixing with commercialized fungicides were investigated in greenhouse test with barley seedlings. While protective activity of PNPP showed 90% at $1,000{\mu}g/mL$, that of LN 13.0 91.2%, tile best among 8 surfactants used in curative test. With $500{\mu}g/mL$, LN 13.0 showed 4% of disease percentage on the first leaf of narley continuously 4 days after the curative application. Excent for PNPP, the other surfactants, including NP 13.0, LN 13.0, and PAS, showed good inhibitory activity against spore germination in water agar medium amended with those surfactants. PAS, which showed very poor effect against barley powdery mildew in greenhouse test, strongly inhibited spore germination. Fungicide of triadimefon and triforine showed no controlling activity against Erysiphae graminis in narley seedlings, but they highly controlled powdery mildew in case of addition with $500{\mu}g/mL$ of LN 13.0 and Tween 20. SP 13.0, NP 13.0, LN 13.0 and DBC showed severe phytotoxicity in first leaf of barley seedlings, but Tween 20, SLIS, PAS, and PNPP not at $1,000{\mu}g/mL$.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.655-662
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• 1992

Pectate lyase produced by recombinant strain containing pectate lyase gene from alkalitolerant Bacillus sp. YA-14 was succesively purified with 257.6 purification folds and a 10.2% yields by the affinity method, eM-cellulose column chromatography followed by gel filtration on Sephadex G-I00 column. The optimal pH and temperature for pectate lyase activity were 10.0 and $60^{\circ}C$, respectively. The enzyme was stable between pH 4.0 and 10.0, and up to $50^{\circ}C$. The molecular weight of this enzyme was estimated to be 43,000 daltons by SDS-PAGE. Amino acid analysis showed that the enzyme contained more polar and basic amino acids, especially serine, glycine and tyrosine, than that of various pectate lyase from other strains. The N-terminal amino acid sequence was Ala-Asp-Leu-Gly-His-Gln-Thr.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.93-97
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• 1991

The enzymatic properties of purified CGTase from alkalophilic Bacillus sp. YC-335 have been examined. Apparent Vmax values of the enzyme in transferring glycosyl residues ${\alpha}-,\;{\beta}-and\;{\gamma}-cyclodextrin(CD)$ to sucrose were $16.13,\;21.8\;and\;9.8{\mu}moles/min/mg\;protein$, respectively and Km values of the corresponding CD were 1.68, 0.33 and 0.37 mM, respectively. A number of saccharides, specially starch hydrolyzates such as glucose and maltose, could activate the dextrinizing activity of the enzym. However, the dextrinizing activity was inhibited by ${\beta}-CD$. It was found from Lineweaver-Burk plot that the inhibition of CGTase by ${\beta}-CD$ was noncompetitive. High performance liquid chromatographic analysis showed that the enzyme has three kinds of activity ; transglycosylation and disproportionation as well as cyclization.