• Journal of Life Science
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• v.20 no.4
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• pp.487-495
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• 2010

A microorganism hydrolyzing carboxymethylcellulose (CMC) was isolated from seawater, identified as Psychrobacter aquimaris by analysis of 16S rDNA sequences, and named P. aquimari LBH-10. This strain produced an acidic carboxymethylcellulase (CMCase), which hydrolyzed carboxymethylcellulose (CMC), cellobiose, curdlan, filter paper, p-nitrophenyl-$\beta$-D-glucopyranoside (pNPG), pullulan, and xylan, but there was no detectable activity on avicel and cellulose. The optimal temperature for CMCase produced by P. aquimari LBH-10 was $50^{\circ}C$ and more than 90% of its original activity was maintained at broad temperatures ranging from 20 to $50^{\circ}C$ after 24 hr. The optimal pH of the CMCase was 3.5, and more than 70% of its original activity was maintained under acidic conditions between pH 2.5 and 7.0 at $50^{\circ}C$ after 24 hr. The optimal pH of CMCase produced by P. aquimaris LBH-10 seems to be lower than those produced by any other bacterial and fungal strain. $CoCl_2$, EDTA, and $PbCl_2$ at a concentration of 0.1 M enhanced CMCase-produced P. aquimaris LBH-10, whereas $HgCl_2$, KCl, $MnCl_2$, $NiCl_2$, and $SrCl_2$ inhibited it.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.70-75
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• 2013

Seven medicinal plant extracts were tested for antifungal activities against six species of the major turfgrass pathogenic fungi (Colletotrichum graminicola, Pythium spp., Rhizoctonia cerealis, Rhizoctonia solani AG1-1, Rhizoctonia solani AG2-2, and Sclerotinia homoeocarpa) using paper disk diffusion method. Three medicinal plant extracts, including Pinus densiflora showed antifungal activities. In suppression of mycelium growth test, on medium adding P. densiflora extract showed that inhibition rate of mycelium growth were above 80% in 10 mg/10 ml concentration of the extract. The inhibition rate of Pythium spp. was 100% and C. graminicola was 84.3% in 10 mg/10 ml concentrations of P. densiflora extract, respectively. In particularly, the inhibition rate of Pythium spp. was 89.5% in 2 mg/10 ml concentrations of P. densiflora extract. As a result, P. densiflora extract showed high antifungal activity to Pythium spp. and C. graminicola of the turfgrass pathogen in in vitro test.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.272-278
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• 2015

Colletotrichum gloeosporioides is one of the most serious pathogens of persimmon in Korea. In 2013, 67 isolates of C. gloeosporioides were isolated from infected fruits, leaf and twigs of persimmon (Diosprosi kaki) at Sangju, Gyeongsangbukdo and fungal responses against five fungicides (prochloraz manganese complex, tebuconazole, mancozeb+myclobutanil, fluquinconazole+prochloraz, and tebuconazole+tolyfluanid) were evaluated by their growth on the fungicide-medium. All isolates were inhibited mycelium growth on the medium with each recommended application concentration of flied. $EC_{50}$ (${\mu}g/ml$) of tebuconazole was from 0.02 to 1.04 and average was 0.31. $EC_{50}$ (${\mu}g/ml$) of prochloraz manganese complex was 0.02~0.23 average was 0.078. Average $EC_{50}$ values (${\mu}g/ml$) of Fluquinconazole+Prochloraz (FP) was 0.029. On the basis $EC_{50}$ (${\mu}g/ml$), the correlation coefficient (r) between tebuconazole and prochloraz manganese complex, prochloraz manganese complex and FP, tebuconazole and FP were 0.42, 0.44 and 0.27, respectively.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.309-312
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• 2013

Fungal cell walls consist of various glucans and chitin. Fungi produce chitinases for their growth and development. The inky cap, Coprinellus congregatus, produces at least two different chitinases during its life cycle. Chitinase 1 (chi1) is expresses throughout its life cycle while chitinase 2 (chi2) is expressed at the mushroom autolysing phase. The cloned cDNA of chi1 is successfully expressed as a fusion protein with c-myc in Pichia pastoris, and purified by the affinity chromatography. The optimum pH and temperature of Chi1 was pH 8.0 and $35^{\circ}C$, respectively when 4-nitrophenyl N,N',N"-triacetyl-${\beta}$-D-chitotrioside was used as the substrate. The $K_m$ value and $V_{max}$ for the substrate was 0.780 mM and 0.10 OD $min^{-1}unit^{-1}$, respectively. The addition of purified Chi1 resulted in total growth inhibition against several plant pathogenic fungi such as Alternaria alternata, Fusarium graminearum and Trichoderma harzianum at the concentration of 60 ${\mu}g/ml$.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.4
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• pp.561-566
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• 2008

Two experiments were conducted to evaluate nutritive value of cell mass from lysine production (CMLP) as a protein supplement for ruminants. In each experiment, animals were fed a diet containing 40% of forages and 60% of concentrates, mainly composed of rice straw and ground corn, respectively, to meet the maintenance requirements, and the diets were formulated to supply equal amounts of energy and nitrogen among treatments. In order to investigate the effect of CMLP on ruminal fermentation (Experiment 1), three Korean native goats weighing $26.1{\pm}1.4kg$ were allotted into individual cages with a $3{\times}3$ Latin square design. Each animal was fed one of three protein sources (CMLP, soybean meal (SBM), and urea). Rumen pH, bacterial and fungal counts, volatile fatty acid concentrations and acetate to propionate ratio were not significantly different among treatments. Concentration of propionate, however, was higher in SBM treatment (14.1 mM) than in CMLP (8.7 mM) or urea (9.3 mM) treatments. There was significantly more branch-chain volatile fatty acid production in CMLP (1.9 mM) and SBM (1.8 mM) treatments than in urea (1.3 mM) treatment. The number of protozoa was the highest in urea treatment, followed by CMLP and SBM treatment with significant differences. A metabolic trial (Experiment 2) was conducted to measure in vivo nutrient digestibility and nitrogen retention in Korean native goats fed CMLP and SBM. Two heavy ($35.0{\pm}1.2kg$) and two light ($25.0{\pm}0.9kg$) Korean native goats, caged individually, were used in this experiment. A heavy and a light animal were paired and supplemented with either CMLP or SBM. The animals fed CMLP showed a trend of lower total tract digestibility in all the nutrients measured; however, there was no statistical significance except for digestibility of ether extract. Nitrogen digestibility of CMLP was estimated to be about 7% units lower than that of SBM. There was a tendency for lower nitrogen retention in CMLP treatment (35.9%) compared to SBM treatment (42.3%). In summary, CMLP can be a good protein source for ruminant animals from nutritional and economic perspectives and may replace some, if not all, of SBM in a diet without losing nitrogen utilization efficiency. Further research is warranted for investigating the effect of CMLP fed with easily fermentable forage and the effective level of CMLP for replacing SBM.

• Journal of Applied Biological Chemistry
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• v.52 no.1
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• pp.28-32
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• 2009

The bacterial toxin, tolaasin, causes brown blotch disease on the cultivated mushrooms by collapsing fungal and fruiting body structure of mushroom. Cytotoxicity of tolaasin was evaluated by measuring hemolytic activity because tolaasins form membrane pores on the red blood cells and destroy cell structure. While we investigated the inhibitions of hemolytic activity of tolaasin by $Zn^{2+}$ and $Cd^{2+}$, we found that $Ni^{2+}$ is another antagonist to block the toxicity of tolaasin. $Ni^{2+}$ inhibited the tolaasin-induced hemolysis in a dose-dependent manner and its Ki value was $\sim10$ mM, implying that the inhibitory effect of $Ni^{2+}$ is stronger than that of $Cd^{2+}$. The hemolytic activity was completely inhibited by $Ni^{2+}$ at the concentration higher than 50 mM. The effect of $Ni^{2+}$ was reversible since it was removed by the addition of EDTA. When the tolaasin-induced hemolysis was suppressed by the addition of 20 mM $Ni^{2+}$, the subsequent addition of EDIA immediately initiated the hemolysis. Although the mechanism of $Ni^{2+}$ -induced inhibition on tolaasin toxicity is not known, $Ni^{2+}$ could inhibit any of fallowing processes of tolaasin action, membrane binding, molecular multimerization, pore formation, and massive ion transport through the membrane pore. Our results indicate that $Ni^{2+}$ inhibits the pore activity of tolaasin, the last step of the toxic process.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.124-129
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• 2020

Sorghum (Sorghum bicolor L.) is an annual crop belonging to Poaceae, and is the fifth-largest crop after maize, wheat, rice, and barley. This study was conducted to establish an efficient seed sterilization method to manage fungal or bacterial infections of germinating sorghum seeds. Two varieties of sorghum seeds (BTx623 and SAP317) were treated with benomyl-thiram and thiophanate-methyl triflumizole which are known to be effective disinfectants for sorghum seeds. For SAP317, the highest germination rate was accomplished with 24-hour treatment of both chemicals at a 200× dilution rate. For BTx623, the highest germination rate was observed after 24-hour treatment at a 200×/400× dilution rate for benomyl-thiram and control/200× for thiophanate-methyl triflumizole. Consequently, the optimal treatment for the seed disinfection in sorghum seeds may be at the dilution rate of 200× or 400× for 24 hours.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.321-329
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• 2014

This experiment was conducted to establish an analytical method for residues of amisulbrom, as recently developed an oomycete-specific fungicide showing inhibition of fungal respiration, in crops using HPLC-UVD/MS. Amisulbrom residue was extracted with acetonitrile from representative samples of five raw products which comprised apple, green pepper, kimchi cabbage, potato and hulled rice. The extract was diluted with 50 mL of saline water and directly partitioned into dichloromethane to remove polar co-extractives in the aqueous phase. For the hulled rice sample, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized Florisil column chromatography. On an octadecylsilyl column in HPLC, amisulbrom was successfully separated from sample co-extractives and sensitively quantitated by ultraviolet absorption at 255 nm with no interference. Accuracy and precision of the proposed method was validated by the recovery test on every crop samples fortified with amisulbrom at 3 concentration levels per crop in each triplication. Mean recoveries ranged from 85.3% to 105.6% in five representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation (LOQ) of amisulbrom was 0.04 mg/kg as verified by the recovery experiment. A confirmatory method using LC/MS with selected-ion monitoring technique was also provided to clearly identify the suspected residue. The proposed method was sensitive, reproducible and easy-to-operate enough to routinely determine the residue of amisulbrom in agricultural commodities.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.176-181
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• 2010

Brown patch (Rhizoctonia solani AG1-1), dollar spot (Sclerotinia homoeocarpa), pythium blight (Pythium spp.), anthracnose (Colletotrichum graminicola), yellow patch (Rhizoctonia cerealis) and Zoysia patch (Rhizoctonia solani AG2-2) are the major turfgrasses diseases in Korea. In this study, 23 medicinal plant extracts were tested for antifungal activities against turfgrass pathogenic fungi. In paper disk diffusion method, 12 medicinal plant extracts, including Sophora flavescens, showed antifungal activity. Also, in the test of antifungal activity on media contained the extracts of S. flavescens, Curcuma longa, Rheum undulatum, Coptis chinensis and Asiasarum sieboldi showed above 80% inhibitory effects on the mycelial growth in 110 mg/10 ml concentration of the extracts. S. flavescens, in particularly, showed antifungal activity against the six turfgrass pathogenic fungi. The inhibition rate of S. homoeocarpa was 100% in 10 mg/10 ml, 5 mg/10 ml and 2 mg/10 ml concentrations of C. longa extract. In case of Pythium spp., the extracts of S. flavescens, R. undulatum and C. chinensis showed 100 % inhibition rate on the test media.

• Applied Biological Chemistry
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• v.18 no.3
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• pp.177-182
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• 1975

The analysis of Jerusalem artichoke showed that it contains 12.09% of Inulin. The results obtained from the examination of the conditions for fructose production by cultivating Pencillum sp 1 in the Jerusalem articoke medium were as follows: 1. The optimum amount of water added to Jerusalem artichoke was 2.5 $\ell$ of distilled water per ㎏ of fresh Jerusalem artichoke. It this case, the concentration of Inulin was 4% (w/v). 2. The optimum temperature was $30^{\circ}C$, the initial optimum pH was 5.0 and the optimum cultural period was 72 hours. 3. Shaking culture with 50 ml of the medium and 120 oscills/min in 500 ml shaking flask was most effective as the culture method. 4. 0.1% of $NH_4H_2PO_4$ as a nitrogen source, 0.001 of $FeSO_47H_20$ and 0.001% of $MgSO_47H_2$ as metal salts were most effective. 5. Fructose production continued to increase for 72 hours under the optimum conditions for cultivation and the highest production rate to the Inulin was 95.25%.