• Food Science and Preservation
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• v.24 no.7
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• pp.885-890
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• 2017

For the construction of the microbial monitoring method, anti-Salmonella polyclonal antibodies (pAbs) were produced from a rabbit and purified by saturated ammonium sulfate precipitation and protein A affinity column. The reactivity of anti-Salmonella pAbs was compared to that of commercial ones by using an indirect ELISA. The specificity of anti-Salmonella pAbs was investigated using 20 Salmonella serotypes and 20 non-Salmonella strains. A capturing ability of anti-Salmonella pAbs was investigated by exposing antibody-immobilized gold biosensor to different concentration of Salmonella mixture. Anti-Salmonella pAbs were successfully produced and purified with an antibody concentration of 2.0 mg/mL The reactivity of purified anti-Salmonella pAbs was greater than that of commercial one at all tested concentrations. All Salmonella serotypes, except S. Diarizonae, showed excellent binding efficiency with purified anti-Salmonella pAbs. Moreover, the purified anti-Salmonella pAbs showed excellent specificity against all non-Salmonella strains. The anti-Salmonella pAbs immobilized on the gold biosensor demonstrated the successful capturing capability against Salmonella with a dose-response manner. Therefore, the anti-Salmonella pAbs exhibited sufficient reactivity, specificity, as well as capturing capability against Salmonella to be considered as a bio-recognition element.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.91-95
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• 1963

The basic studies of adsorption characteristics of collector on monazite were made by electrophoretic measurement and by determination of the adsorption of some typical flotation collectors. By above measurements made on monazite, it is concluded that $H^+\;and\;OH^-$ are identified to act as potential determining ions and thus the electrical properties of monazite is controlled by the pH of the solution. Therefore, anionic collectors are adsorbed on positively charged surfaces and cationic collectors on negatively charged surfaces, which in turn controls the effective flotation condition with respective collectors for this mineral. These results have been correlated with its flotation behavior obtained by Hallimond tube test.

• Nuclear Engineering and Technology
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• v.4 no.4
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• pp.306-321
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• 1972

Molecular reorientation in (NH$_4$)$_2$SO$_4$, has been studied by cold neutron scattering. For T=300$^{\circ}$K data, the isolated quasielastic spectra and form-factors at various scattering angles are compared with four reorientational models based on SKOLD theory. Front these, it is concluded that the NH$_4$ions are performing either 3-fold four axes or 2-fold three axes reorientation with $\tau$$_{c}$=2.0$\times$10$^{-11}$ sec. The temperature dependence of f. is studied over 100$^{\circ}$K-413$^{\circ}$K and for the high-temperature phase, the widths of composite spectra are compared with the results from NMR relaxation measurements. All the results have shown that the neutron scattering method is capable of giving detalis of the reorientational modes in solids and therefore some discussions are given on the application of this method. A study of the form-factor is applied for NH$_4$I (Phase I) by comparing the measurement with the calculation based on free rotation approximation and proposed a reorientation model of NH$_4$ ions in the octahedral potential cage with $\tau$$_{c}$$\leq$10$^{-12}$ sec. Also a brief theoretical prediction for the effect of reorientational motions on the inelastic spectrum is discussed.sed.

• Journal of Life Science
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• v.18 no.1
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• pp.103-108
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• 2008

An agar-degrading marine bacterium, strain AS-1 was isolated from the seawater. The strain AS-1 was identified as Sphingomonas paucimobilis (90% probability) by VITEK. The optimum medium for agarase activity of the isolated strain was determined to be marine medium, marine broth 2216 containing 0.1% agar as carbon source. An extracellular agarase was purified 104-fold from the culture supernatant by ammonium sulfate precipitation, ion exchange chromatography and gel filtration methods. The molecular weight of the purified enzyme was estimated to be 80 kDa by SDS-PAGE. The optimum pH and temperature for activity were 7.0 and $40^{\circ}C$, respectively. Antioxidative activity of the strain AS- was 72% in the supernatant cultured for 12 h. The culture supernatant of the strain AS-1 showed antibacterial activity against bacteria causing putrefaction and food poisoning such as Escherichia coli, Staphylococcus aureus and Proteus vulgaris. However, the cell growth of the lactic aicd forming strain, Lactobacillus plantarium was promoted by the treatment of 10% culture supernatant of an agar-degrading strain.

• Journal of Life Science
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• v.25 no.2
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• pp.180-188
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• 2015

The bacterial strain isolated from Kimchi showed antibacterial activity against Micrococcus luteus IAM 1056. The selected strain was identified as Lactococcus lactis by 16S rRNA nucleotide sequence analysis and named as Lactococcus sp. KD 28. The treatment of culture supernatant with proteinase K removed antibacterial activity, indicating its proteinaceous nature, a bacteriocin. This bacteriocin was sensitive to hydrolytic enzymes such as ${\alpha}$-chymotrypsion, trypsin, proteinase K, lipase, ${\alpha}$-amylase and subtilisin A. The bacteriocin was highly thermostable and resistant to heating at $80^{\circ}C$ for up to an hour but 50 % of the total activity was remained at $100^{\circ}C$ for 30 min. The pH range from 2.0 to 8.0 had no effect on bacteriocin activity and it was not affected by solvents such as acetonitrile, isopropanol, methanol, chloroform and acetone up to 50% concentration. The bacteriocin showed antibacterial activity against M. luteus IAM 1056, Lactobacillus delbrueckii subsp. lactis KCTC 1058, Enterococcus faecium KCTC 3095, Bacillus cereus KCTC 1013, B. subtilis KCTC 1023, Listeria ivanovii subsp. ivanovii KCTC 3444, Staphylococcus aureus subsp. aureus KCTC 1916, B. megaterium KCTC 1098 and B. sphaericus KCTC 1184. The bacteriocin was purified through ammonium sulfate concentration, SP-Sepharose chromatography and RP-HPLC. The molecular weight was estimated to be about 3.4 kDa by tricine-SDS-PAGE analysis.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.148-154
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• 2003

Moraxella sp. CK-l is known to inhibits the growth of Anabaena cylindrica, a cyanobacterium. It has been documented that the ability of this growth inhibition of Anabaena cylindrica was attributed to extracellular autolysin from Moraxella sp. CK-l. However, it remains to be elucidated identification and characterization of autolysin have yet been elucidated. In this study, we tried to purify and identify autolysin secreted from Moraxella sp. CK-l. Cells were grown in a complex liquid medium (BGC-11) and culture supernatants were collected, followed by ammonium sulfate fractionation. Fractions were further separated with anion exchange column, Mono-Q, in FPLC system and analyzed by SDS/PAGE. The fraction containing high autolysin activity showed a single distinct protein peak in anion column and molecular mass of about 17 kDa in SDS/PAGE. Nterminal amino acid sequencing of the protein was analyzed, of which result showed the homology with some proteases, including extracellular serine protease, Dichelobacter nodosus.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.1
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• pp.75-86
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• 1994

Garbage composting was studied in a controlled batch reactor with the addition of cooked rice as a biodegradable carbon source to find the effect of C/N ratio control on composting. And composting of bulking agents such as sawdust and wheat straw were tested with the addition of ammonium sulfate as a nitrogen source. As expected, biodegradation of the garbage having low C/N ratio was improved to some extent when foreign carbon was added. But bulking agents used in this study exerted slightly biodegradable carbon potential, indicating that the estimation of the dose of additional carbon considering desirable C/N ratio was not reasonable when lignocellulosic bulking material was added to garbage. It was found that the optimum moisture content increased with sawdust addition meaning the C/N ratio increment. Considering the above results, it was suggested that 78g sawdust per 100g garbage should be mixed to make C/N ratio to 25 and moisture content to 56% for effective composting of the garbage studied in this paper.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.92-97
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• 1988

Cysteinylglycinase was partially purified from Proteus mirabilis by consecutive procedure. The specific activity was increased about 16-fold to that of cell-free extract. The enzyme was found rather unstable on ammonium sulfate precipitation ann the precipitated enzyme protein became partially insoluble during dialysis. The precipitated enzyme was found to be solubilized by treatment of 4% Triton X-100 effectiviely, The optimum temperature and pH of the enzyme activity were 35$^{\circ}C$ and 7.3, respectively. After heat treatment of the enzyme at 5$0^{\circ}C$ for 30 min, it lost the activity to 70%. The enzyme was stable at pH 7.0-8.0. The molecular weight of the cysteinylglycinase was found to be about 190,000 by Sephadex G-150 gel filtration. The enzyme was activated by the addition of Mn$^{2+}$ and $Mg^{2+}$ ions. The maximal activation was obtained in preincubation with $Mg^{2+}$ ion for 30 min. The enzyme catalyzed the hydrolysis of various dipeptides and tripeptides. The Km and Vmax values for cysteinylglycine were 1.60 mM and 0.24 m unit/ mg, respectively.

• Journal of Microbiology and Biotechnology
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• v.23 no.2
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• pp.225-236
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• 2013

Among several bacteria examined, an antibacterial-producing Lactobacillus strain with probiotic characteristics was selected and identified based on 16S rRNA gene sequencing. Subsequent purification and mode of action of the antibacterial compounds on target cells including E. coli were investigated. Maximum production of the antibacterial compound was recorded at 18 h incubation at $30^{\circ}C$. Interestingly, antibacterial activity remained unchanged after heating at $121^{\circ}C$ for 45 min, 24 h storage in temperature range of $70^{\circ}C$ to room temperature, and 15 min exposure to UV light, and it was stable in the pH of range 2-10. The active compounds were inactivated by proteolytic enzymes, indicating their proteinaceous nature, and, therefore, referred to as bacteriocin-like inhibitory substances. Isolation and partial purification of the effective agent was done by performing ammonium sulfate precipitation and gel filtration chromatography. The molecular mass of the GFC-purified active compound (~3 kDa) was determined by Tris-Tricine SDS-PAGE. To predict the mechanisms of action, transmission electron microscopy (TEM) analysis of ultrathin sections of E. coli before and after antibacterial treatment was carried out. TEM analysis of antibacterial compounds-treated E. coli demonstrated that the completely altered bacteria appear much darker compared with the less altered bacteria, suggesting a change in the cytoplasmic composition. There were also some membrane-bound convoluted structures visible within the completely altered bacteria, which could be attributed to the response of the E. coli to the treatment with the antibacterial compound. According to the in vivo experiments oral administration of L. plantarum HKN01 resulted in recovery of infected BALB/c mice with Salmonella enterica ser. Typhimurium.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.201-208
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• 2010

The $SO_2$ and $NO_x$ removal with an activated coke catalyst was conducted by a two-stage reaction which first $SO_2$ was oxidized to $H_2SO_4$ and then $NO_x$ was reduced to $N_2$. But if unreacted sulfur dioxide entered in the second stage, the $NO_x$ reduction was hindered by the reaction with ammonia. In this study, experimental investigations by using lab-scale column apparatus on the product and the reactivity of $SO_2$ with ammonia over coke catalyst which was activated with sulfuric acid was carried out through ultimate analysis DTA, TGA and SEM of catalyst before and after the reaction. Also, the effect of reaction emperature on the reactivity of $SO_2$ with ammonia was determined by means of breakthrough curves with time. The obtained results from this study were summarized as following; Activated cokes were decreased carbon component and increased oxygen and sulfur components in comparison with original cokes. The products over coke catalyst were faced fine crystal of $(NH_4)_2SO_4$, which results in the pressure loss of reacting system. The order of general reactivity in terms of the reaction temperature after breakthrough for $SO_2$ was found to be $150^{\circ}C$ > $200^{\circ}C$ > $100^{\circ}C$. This was related to adsorption amounts of ammonia on the activated cokes.