• Korean Journal of Microbiology
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• v.33 no.4
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• pp.237-241
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• 1997

Lipase (EC 3.1.1.3) in the culture filtrate of Streptomyces coelicolor A3(2) was active on ${\alpha}$-naphthyl-butyrate as well as on various triacylglycerols with different lengths of acyl chains. The extracellular lipase was purified 15-fold by ammonium sulfate fractionation, Sephadex G-100, DEAE-Cellulose and Phenyl-Sepharose CL4B column chromatography with overall yield of 16%. It showed an molecular weight of 34.7 kDa by SDS-polyacrylamide gel electrophoresis. The enzyme activity with tributyrin as substrate was optimal at pH 8.0~9.0 and at $37^{\circ}C$. The enzyme activity decreased when the chain length of acyl group of triacyglycerol increased. A-factor, a hormone-like regulator of Streptomyces differentiation inhibited the lipase activity, which might corelate with the low enzyme activity in early exponential growth phase.

• Journal of Life Science
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• v.19 no.8
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• pp.1039-1046
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• 2009

The cytochrome P450s (P450s) metabolizing natural products are among the most versatile biological catalysts known in plants, but knowledge of the structural basis for their broad substrate specificity has been limited. The activity of p-coumarate 3-hydroxylase (C3H) is thought to be essential for the biosynthesis of lignin and many other phenylpropanoid pathway products in plants however, all attempts to express and purify the protein corresponding C3H gene have failed. As a result, no conditions suitable for the unambiguous assay of the enzyme are known. The detailed understanding of the mechanism and substrate-specificity of C3Hdemands a method for the production of active protein on the milligram scale. We have developed a bacterial expression and purification system for the plant C3H, which allows for the quick expression and purification of active wild-type C3H via introduction of combinational mutagenesis. The modified cytochrome P450 C3H ($C3H_{mod}$) could be purified in the absence of detergent using immobilized metal affinity chromatography and size exclusion chromatography following extraction from isolated membranes in a high salt buffer and catalytically activated. This method makes the use of isotopic labeling of C3H for NMRstudies and X-ray crystallography practical, and is also applicable to other plant cytochrome P450 proteins.

• Environmental Engineering Research
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• v.23 no.1
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• pp.36-45
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• 2018

The phosphogypsum (PG) is a byproduct of the phosphate fertilizers manufacture. The world production estimated to 200 million tons per year induces environmental threats and storage problems, which requires strict policies to limit pollution and encourage its valorization. This paper presents a purification process of the crude PG including treatment with a diluted sulfuric acid, floatation, filtration and washing. The purified PG is used to produce plaster. The process optimization was conducted using a full factorial design. The significant factors considered in the experimental study are temperature ($X_1$), volume of sulfuric acid solution ($X_2$) and PG quantity ($X_3$). The main effects and interaction effects of these factors on the responses of the % $P_2O_5$, % F, Total Organic Carbon (TOC) ($mg{\cdot}kg^{-1}$) and pH were analyzed. The optimum conditions for $X_1$, $X_2$ and $X_3$ were found to be $60^{\circ}C$, 3 L and 1 kg, respectively and the optimized pH values was found to be 6.2. Under these conditions, 60% of $P_2O_5$, 95% of Fluorine and 98% of TOC were removed from PG. The predicted values were found approximately the same as the experimental ones. The plaster produced with purified PG was found to have similar properties to that produced from natural gypsum.

• KSBB Journal
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• v.25 no.3
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• pp.205-214
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• 2010

Many successive liquid-liquid extractions occur enabling purification of the crude material to occur. In high performance counter-current chromatography (HPCCC), crude material is partitioned between two immiscible layers of solvent phases. The stationary phase (SP) is retained by hydrodynamic force field effect and the mobile phase (MP) is pumped through the column. Purification occurs because of the different solubility of the components in the liquid mobile and stationary phases. There are many key benefits of liquid stationary phases such as high mass and volume injection loadings, total sample recovery, and easy scale-up. Many researchers showed that predictable scale-up from simple test is feasible with knowledge of the stationary phase retention for the planned process scale run. In this review we review the recent advances in HPCCC research and also describe the key applications such as natural products and synthetics (small or large molecules).

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.395-402
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• 2005

Biologically active recombinant human follicle stimulating hormone (rhFSH) was produced in Chinese hamster ovary cells and purified by a series of chromatographic steps. The chromatographic steps included anion-exchange chromatography (DEAE Sepharose F/F, Q Sepharose F/F), hydrophobic interaction chromatography (Source 15 PHE), and hydroxyapatite chromatography (Macro-Prep ceramic hydroxyapatite type I). A distinctive step of the purification process developed was the use of ZnCl$_2$ for the removal of non-glycosylated or lowly-glycosylated FSH and impurities through co-precipitation with Zn$^{2+}$. Purified rhFSH was identified and characterized by several physicochemical and biological methods such as gel electrophoresis, high-performance liquid chromatography, amino acid analysis, carbohydrate analysis, and biological activity. The overall yield of the purification was ~$30\%$. The rhFSH preparation obtained showed high purity (>$99\%$) and high in vivo potency (>16,000 IU/mg). Carbohydrate analysis suggested that the purified rhFSH contained approximately $40\%$ (w/w) carbohydrate with di­or tri-antennary structure on average, which is somewhat more heavily sialylated than commercially available rhFSH. In conclusion, the results of these analyses established an identity of the purified rhFSH with natural FSH from human pituitary glands, and furthermore, the purified rhFSH preparation showed higher in vivo potency and was slightly more heavily sialylated than commercially available rhFSH.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1307-1314
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• 2015

Leukemia inhibitory factor (LIF) is a member of the IL-6 cytokine family, having pleiotropic actions such as maintaining stem cell pluripotency and enabling blastocyst implantation. Because the action of LIF is mediated by a ligand-receptor interaction with the LIF receptor (LIF-R), an antagonist for LIF-R has been developed to inhibit LIF-induced signaling. In this study, we present a novel method for the production and purification of an antagonist to human LIF-R (hLA). His-tagged hLA was expressed in E. coli, and simple purification methods without any endopeptidase cleavage were designed. In addition, we determined the optimal temperature conditions for enhancing the production of soluble hLA. Finally, the bioactivity of His-tagged hLA was examined using STAT3 phosphorylation and receptivity of human endometrial ECC-1 cells. Our strategy provides a rapid and efficient method to produce biologically active recombinant hLA.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.89-95
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• 2021

As the influence of fine dust on society spreads gradually, the public's interest in indoor air is increasingly rising. Air-purifying plants are drawing keen attention due to their natural purifying function enabled by plant physiology. However, as their fine dust reduction mechanism is limited to adsorption only, vegetation bio-filters that optimize purification effects through integration with air-conditioning systems is rising as an alternative. In accordance with the relevant standard test methods, this study looked into the fine dust reduction assessment method by air-conditioning airflow volume that can be used for the industrial spread of vegetation bio-filters. In the case of PM₁₀ at 300 ㎍/m³, it was in the order of EG-B(3,500CMH, 29 min.) < EG-A (2,500CMH, 37 min.) < CG(0CMH, 64 min.) for reaching the maintenance level (100 ㎍/m³) of publicly used facilities. For reaching the WHO Guideline(50 ㎍/m³) requirement, it was in the order of EG-B (51 min.) < EG-A (160 min.) < CG (170 min.). In the case of PM_2.5, it was in the order of EG-B (26 min.) < EG-A (33 min.) < CG (57 min.) for reaching the maintenance level (50 ㎍/m³) of publicly used facilities. It was in the order of EG-B (48 min) < EG-A (140 min) < CG (158 min) for reaching the WHO Guideline (25 ㎍/m³) requirement. The findings from the analysis showed that fine dust can be reduced most efficiently when the system is operated at 3,500CMH level. The limitation of this study is that due to the absence of a way of assessing the stress of plants in vegetation bio-filters, generating optimal air-conditioning air flow of the relevant system and economics analysis against the existing facility-type air purification system have been clarified, which should be explored further though follow-up studies.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1663-1665
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• 2008

Acyl-coenzyme A: cholesterol acyltransferase (ACAT) catalyzes cholesterol esterification and plays an important role in the intestinal absorption of cholesterol, hepatic production of lipoproteins, and accumulation of cholesteryl ester within cells. During the course of screening to find ACAT inhibitors from microbial sources, the present authors isolated pyripyropene A from Penicillium griseofulvum F1959. Pyripyropene A, an ACAT2-specific inhibitor, has already been produced from Aspergillus fumigatus. Yet, Aspergillus fumigatus is a pathogen and only produces a limited amount of pyripyropene A, making the isolation of pyripyropene A troublesome. In contrast, Penicillium griseofulvum F1959 was found to produce approximately 28 times more pyripyropene A than Aspergillus fumigatus, plus this report also describes the ideal conditions for the production of pyripyropene A by Penicillium griseofulvum F1959 and its subsequent purification.

• Journal of Soil and Groundwater Environment
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• v.16 no.5
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• pp.24-30
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• 2011

Tidal flats which are ecologically sensitive, are hard to remediate once they are contaminated by oil spill accidents. Traditional oil remediation measures focus on removal efficiency, and their improper implementation can adversely affect crude oil contaminated coastal areas and greatly disrupt the structure and functions of crude oil contaminated tidal flats. In this study, the oil degradation due to the implementation of remediation measures naturally enhanced using air and natural oil sorbents was evaluated in the lower strata of tidal flats. The effects of air and natural oil sorbents on oil degradation for two concentration levels (< 500 ppm and > 500 ppm) were tested at artificially contaminated tidal flats. Fifty days after these treatments, the natural oil sorbent treatment showed the lowest total petroleum hydrocarbon (TPH) concentration ($4.46{\pm}1.47%$) at the low concentration level, whereas both air and natural oil sorbent treatments showed high degradation efficiencies at the high concentration level ($29.30{\pm}4.39%$). Although the phosphatase activity decreased for all treatments, there was no significant difference between the decreases for the different treatments; on the other hand, B-glucosidase activities were high for both air and natural oil sorbent treatments. Although degradation efficiencies decreased as the concentration increased, the air provision and natural oil sorbent treatment could be an effective ecological restoration measure for oil contaminated tidal flats while minimizing the environmental impact of the remediation efforts.

• Advances in environmental research
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• v.9 no.3
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• pp.215-232
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• 2020

Crude oils are essential source of energy. It is majorly found in geographical locations beneath the earth's surface and crude oil is the main factor for the economic developments in the world. Natural crude oil contains unrefined petroleum composed of hydrocarbons of various molecular weights and it contains other organic materials like aromatic compounds, sulphur compounds, and many other organic compounds. These hydrocarbons are rapidly getting degraded by biosurfactant producing microorganisms. The present study deals with the isolation, purification, and characterization of biosurfactant producing microorganism from oil-contaminated soil. The ability of the microorganism producing biosurfactant was investigated by well diffusion method, drop collapse test, emulsification test, oil displacement activity, and blue agar plate method. The isolate obtained from the oil contaminated soil was identified as Bacillus subtilis. The identification was done by microscopic examinations and further characterization was done by Biochemical tests and 16SrRNA gene sequencing. Purification of the biosurfactant was performed by simple liquid-liquid extraction, and characterization of extracted biosurfactants was done using Fourier transform infrared spectroscopy (FTIR). The degradation of crude oil upon treatment with the partially purified biosurfactant was analyzed by FTIR spectroscopy and Gas-chromatography mass spectroscopy (GC-MS).