• Journal of Microbiology
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• v.40 no.4
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• pp.340-343
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• 2002

A PCB degrader, Ralstonia eutropha H850 was shown to induce bphC gene encoding 2,3-dihydroxy-biphenyl-1,2-dioxygenase in a carvone-amended pure culture in our previous study (Park et al.,1999). The present study was carried out to examine how plant terpenes, as natural substrates, would cause an expression of a PCB degradative gene in soil that was amended with terpenes. The population of Ralstonia eutropha H850 was maintained at least around 10$\^$8/ (CFU/g fresh soil) in the soil amended with carvone or limonene in the presence of succinate as a growth substrate at 50 th day. The gene expression was monitored by RT-PCR using total RNA directly extracted from each soil and bphC gene primers. The bphC gene expression of the seeded strain H850 was observed in the soil amended with biphenyl (4 days) but not with succinate, carvone and limonene. These results indicate that terpenes widely distributed in nature could be a potential inducing substrate for effective PCB biodegration in the soil but their bioavailability and specific induction behavior should be taken into account before PCB bioremediation implementation.

• KSBB Journal
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• v.26 no.5
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• pp.365-373
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• 2011

Effective Microorganisms (EM), a fermented medium developed by Professor Higa at the University of the Ryukyus, is a mixed culture containing dozens of microorganisms which are beneficial to nature including people, animals, plants and many microbial species in environment. EM is known to contain more than 80 kinds of anaerobic or aerobic microbes including photosynthetic bacteria, lactic acid bacteria, yeast, actinomycetes, fungi and so on, with yeast, lactic acid bacteria and photosynthetic bacteria as the main species of EM. Antioxidant effect generated by the concert of complex coexistence and coprosperity among these microbes is considered to be the main source of EM benefits. Currently, EM is earning an increasing attention with applications in agriculture, forestry, animal husbandry, fisheries, environment and medicine among others. At the same time, however, a quantitative interpretation of EM system based on a mixed culture model needs efforts from biochemical engineers for efficient production and further promotion of EM. In this paper, we describe the functions of major microbes in EM and current researches and applications of EM in agriculture, forestry, animal husbandry, fisheries, environment and medicine.

• Membrane Journal
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• v.8 no.2
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• pp.69-76
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• 1998

Membrane technologies have been used frequently in industries, taking advantage of that it is energy-saving and employable in relatively large scale. The fact that a non-mass separating agent is used in mild conditions without phase change in membrane separation makes it a method of choice in the recovery of biological materials. Recently, the development of noble separating modules has been solving the inherent problems in membrane separation, the fouling and the concentration polarization. In addition, membrane separation has broadened its applications from the conventional crude separation to the purificational use by the advent of the new and functional membrane materials. The role of membrane technologies is expected to be enormous in the production and recovery of biological products, considering the excellent applicability of membrane in the fields of integrated separation and in-situ separation, the two trends in modem bioseparation.

• Journal of Microbiology
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• v.41 no.4
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• pp.349-352
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• 2003

Recent studies have shown that some of the PCB (polychlorinated biphenyl)-degraders are able to effectively degrade PCB in the presence of monoterpenes, which act as inducers for the degradation pathway. Rhodococcus sp. T104, an effective PCB degrader, has been shown to induce the degradation pathway by utilizing limonenes, cymenes, carvones, and pinenes as sole carbon sources which can be found in the natural environment. Moreover, the strain T104 proved to possess three separate oxidation pathways of limonene, biphenyl, and phenol. Of these three, the limonene can also induce the biphenyl degradation pathway. In this work, we report the presence of three distinct genes for aromatic oxygenase, which are putatively involved in the degradation of aromatic substrates including biphenyl, limonene, and phenol, through PCR amplification and denaturing gradient gel electrophoresis (DGGE). The genes were differentially expressed and well induced by limonene, cymene, and plant extract A compared to biphenyl and/or glucose. This indicates that substrate specificity must be taken into account when biodegradation of the target compounds are facilitated by the plant natural substrates.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1751-1757
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• 2007

Elastin-like polypeptides (ELPs) undergo a reversible inverse phase transition upon a change in temperature. This thermally triggered phase transition allows for a simple and rapid means of purifying a fusion protein. Recovery of ELPs-tagged fusion protein was easily achieved by aggregation, triggered either by raising temperature or by adding salt. In this study, levansucrase has been used as a model enzyme in the development of a simple one-step purification method using ELPs. The levansucrase gene cloned from Pseudomonas aurantiaca S-4380 was tagged with various sizes of ELPs to functionally express and optimize the purification of levansucrase. One of two ELPs, ELP[V-20] or ELP[V-40], was fused at the C-terminus of the levansucrase gene. A levansucrase-ELP fusion protein was expressed in Escherichia coli $DH5{\alpha}$ at $37^{\circ}C$ for 18 h. The molecular masses of levansucrase-ELP[V-20] and levansucrase-ELP[V-40] were determined as 56 kDa and 65 kDa, respectively. The phase transition of levansucrase-ELP[V-20] occurred at $20^{\circ}C$ in 50 mM Tris-Cl (pH 8) buffer with 3 M NaCl added, whereas the phase transition temperature ($T_t$) of levansucrase-ELP[V-40] was $17^{\circ}C$ with 2 M NaCl. Levansucrase was successfully purified using the phase transition characteristics of ELPs, with a recovery yield of higher than 80%, as verified by SDS-PAGE. The specific activity was measured spectrophotometrically to be 173 U/mg and 171 U/mg for levansucrase-ELP[V-20] and levansucrase-ELP[V-40], respectively, implying that the ELP-tagging system provides an efficient one-step separation method for protein purification.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.35-39
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• 2006

This study was performed to understand temperature effect on retention behavior of fructose and glucose as sugars and lactic acid and acetic acid as organic acids on poly (4-vinylpyridine) resin. The pulse tests were performed to understand temperature effect on retention time of sugars and the results were not shown large change. As it was able to predict with PVP resin not to be used for sugar separation generally, the results were shown poor resolution for separation of sugars and temperature effect on the resolution change of sugars also was not large. On the other hand, in the case of organic acids on PVP resin, the pulse tests were shown temperature effect on the retention behavior was very large. So, the frontal analyses were performed to understand quantitative adsorption behavior of organic acids at 35 and $65^{\circ}C$. These adsorption characteristics of organic acids with PVP resin system can be used to preparative chromatographic process such as SMB (simulated moving bed).

• Korean Chemical Engineering Research
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• v.43 no.6
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• pp.715-721
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• 2005

The SMB chromatography is used to obtain high purification of fructooligosaccharides (FOS), the mixture of kestose and nystose. SMB operation condition is usually determined by triangle theory or standing wave design when reactions do not occur within columns during experiment. Some of the reactions in columns may considerably affect experimental results. FOS can be hydrolyzed and converted into glucose and fructose during operation. To include the effect of reaction, the concentrations of each component at steady state after hydrolysis were used in simulation. The obtained simulation values are well matched with experimental results except sucrose. For sucrose, the experimental results were different from expected one due to the existence of an intermediate component. FOS is easily hydrolyzed and converted into glucose and fructose in more acidic condition and at higher temperature. Hydrolysis reaction can be prevented by the pretreatment of separation resin with NaOH as well as operation under lower temperature.

• Korean Chemical Engineering Research
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• v.43 no.6
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• pp.722-727
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• 2005

Dow99Ca350 (Dowex monosphere 99Ca/350 separation resin), MFG-220, and Finex CS-10GC are ion-exchange resins, and primarily used to separate sugars, and all of these resins have poly styrene DVB backbone, and sulfonyl group. These resins are already used to separate sugars continuously at sugar industry at constant temperature. These resins are used in experiments for understanding temperature effect on retention or adsorption behavior. Using Dow99Ca350, swelling test, porosity test, pulse test, and frontal analysis at various temperatures were performed. In the cases of MFG-220, and Finex CS-10GC, the effect of temperature variation was verified by pulse test. The experimental results are shown that Dow99Ca350, MFG-220, and Finex CS-10GC, which are commercial resins for sugar separation, are stable to temperature variation because the maximum change of retention time of fructose, and glucose are 1.76, and 3.37％ respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.61-66
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• 2001

The aim of this study was to examine how plant terpenoids, as natural growth substrates or inducers, would affect the biodegradation of PCB congeners. Various PCB degraders that could grow on biphenyl and several terpenoids were tested for their PCB degradation capabilities. Degradation activities of the PCB congeners, 4,4-dichlorobiphenyl (4,4-DCBp) and 2,2-dichlorobiphenyl (2,2-DCBp), were initially monitored through a resting cell assay technique that could detect their degradation products. The PCB degraders, Pseudomonas ((S)-(-) limonene, p-cymene and $\alpha$-terpinene) whereas Arthrobacter sp. B1B could not grow on the terpenoids as a sole carbon source. The B1B strain grown on biphenyl exhibited good degradation activity for 4,4-DCBp and 2,2-DCBp, while the activity of strains P166 and T104 was about 25% that of the B1B strain, respectively. Concomitant GC analysis, however, demonstrated that strain T104, grown on (S)-(-) limonene, p-cymene and $\alpha$-terpinene, could degrade 4,4-DCBp up to 30%, equivalent to 50% of the biphenyl induction level. Moreover, strain T104 grown on (S)-(-) limonene, could also degrade 2,2-DCBp up to 30%. This indicates that terpenoids, widely distributed in nature, could be utilized as both growth and/or inducer substrate(s) for PCB biodegradation in the environment.

• KSBB Journal
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• v.22 no.4
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• pp.179-184
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• 2007

This study introduces the characteristics and some applications of repetitive polypeptides, especially to the biomaterial, tissue engineering scaffolds, drug delivery system, and DNA separation systems. Since some fibrous proteins, which consist of repeating peptide monomers, have been reported that their physical properties are changed dramatically by means of temperature alteration or pH shifting. For that reason, fibrous protein-mimetic polypeptides, which are produced by the recombinant technology, can be applied to the diverse biological fields. Repetitive polypeptides can also be used in the bioseparation area such as DNA sequencing, because they make DNA separation possible in free-solution electrophoresis by conjugating DNA fragments to them. Moreover, artificial synthesis of repetitive polypeptides helps to demonstrate the correlations between mechanical properties and structures of natural protein polymer, which have been proven that repetitive domains are affected by the sequence of the repeating domains and the number of repeating subunits. Repetitive polypeptides can be biologically synthesized using some special cloning methods, which are represented here. Recursive directional ligation (RDL) and controlled cloning method (CCM) have been proposed as excellent cloning methods in that we can control the number of repetition in the multimerization of polypeptides and the components of repetitive polypeptides by either method.