• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.475-481
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• 2013

By using ionic liquid 1-hexylpyridinium hexafluorophosphate ($HPPF_6$) based carbon ionic liquid electrode (CILE) as the substrate electrode, a $CoMoO_4$ nanorods and myoglobin (Mb) composite was casted on the surface of CILE with chitosan (CTS) as the film forming material to obtain the modified electrode (CTS/$CoMoO_4$-Mb/CILE). Spectroscopic results indicated that Mb retained its native structures without any conformational changes after mixed with $CoMoO_4$ nanorods and CTS. Electrochemical behaviors of Mb on the electrode were carefully investigated by cyclic voltammetry with a pair of well-defined redox peaks from the heme Fe(III)/Fe(II) redox center of Mb appeared, which indicated that direct electron transfer between Mb and CILE was realized. Electrochemical parameters such as the electron transfer number (n), charge transfer coefficient (${\alpha}$) and electron transfer rate constant ($k_s$) were estimated by cyclic voltammetry with the results as 1.09, 0.53 and 1.16 $s^{-1}$, respectively. The Mb modified electrode showed good electrocatalytic ability toward the reduction of trichloroacetic acid in the concentration range from 0.1 to 32.0 mmol $L^{-1}$ with the detection limit as 0.036 mmol $L^{-1}$ ($3{\sigma}$), and the reduction of $H_2O_2$ in the concentration range from 0.12 to 397.0 ${\mu}mol\;L^{-1}$ with the detection limit as 0.0426 ${\mu}mol\;L^{-1}$ ($3{\sigma}$).

• Membrane Journal
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• v.15 no.4
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• pp.255-271
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• 2005

polymer/layered silicate nanocomposite (PLSNs) is new type of materials, based on clays usually rendered hydrophobic through ionic exchange of the sodium interlayer cation with an onium cation. It could be prepared via various synthetic routes comprising exfoliation adsorption, in situ intercalative polymerization and melt intercalation. The whole range of polymer is used, i.e. thermoplastics, thermosets and elastomers as a matrix. Two types of structure may be obtained, namely intercalated nanocomposites where the polymer chains are sandwiched in between silicate layers and exfolicate nanocomposites where the separated, individual silicate layers are more or less uniformly dispersed in the polymer matrix. This new family of materials exhibits enhanced properties at very low filer level, usually inferior to 5wt$\%$, such as increased mechanical properties, increase in thermal stability and gas barrier properties and good flame retardancy. Gas permeability through the PLSNs films decreased due to increased tortuosity made by intercalation or exfoliation of clay in polymer.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.631-636
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• 1999

The thermostable endo-chitosanase gene from the isolated strain Bacillus sp. KFB-C108 was identified on the basis of a phylogenetic analysis of the 16S rRNA gene sequence, and was cloned into plasmid pUCl8 using E. coli $DH5\alpha$ as the host strain. Positive clones carrying recombinant plasmids (pKCHO I and pKCHO II) containing chitosanase activity were selected using the direct activity staining method. Detailed physical maps showed the two plasmid inserts were identical except that the KCHO II insert (2.6 kb) was 1.8 kb smaller than that of the KCHO I. The recombinant plasmids were analyzed to determine the essential region for chitosanase activity, and a 1.3-kb fragment (KCHO-6) was subcloned into pTrc99A using the EcoRI and BamHI sites to construct pTrc99A/KCHO-6(pTrEB13). The resulting plasmid exerted high chitosanase activity upon transformation of E. coli $DH5{\alpha}cells$, overproducing about 20 times more in the cloned cells than in the wild-type cells. The cloned chitosanase protein exhibited the same molecular weight and catalytic activity similar to those of Bacillus sp. KFB-C108. The cloned enzyme was an endo-type that produced a chitosan tetramer as the major reaction product; however, it produced no monomers or dimers.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.280-286
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• 2007

We evaluated a commercial biopreparation of plant growth-promoting rhizobacteria (PGPR) strains Bacillus subtilis GB03 and B. amyloliquefaciens IN937a formulated with the carrier chitosan (Bio Yield) for its capacity to elicit growth promotion and induced systemic resistance against infection by Cucumber Mosaic Virus (CMV) and Pseudomonas syringae pv. tomato DC3000 in Arabidopsis thaliana. The biopreparation promoted plant growth of Arabidopsis hormonal mutants, which included auxin, gibberellic acid, ethylene, jasmonate, salicylic acid, and brassinosteroid insensitive lines as well as each wild-type. The biopreparation protected plants against CMV based on disease severity in wild-type plants. However, virus titre was not lower in control plants and those treated with biopreparation, suggesting that the biopreparation induced tolerance rather than resistance against CMV. Interestingly, the biopreparation induced resistance against CMV in NahG plants, as evidenced by both reduced disease severity and virus titer. The biopreparation also elicited induced resistance against P. syringae pv. tomato in the wild-type but not in NahG transgenic plants, which degrade endogenous salicylic acid, indicating the involvement of salicylic acid signaling. Our results indicate that some PGPR strains can elicit plant growth promotion by mechanisms that are different from known hormonal signaling pathways. In addition, the mechanism for elicitation of induced resistance by PGPR may be pathogen-dependent. Collectively, the two-Bacilli strain mixture can be utilized as a biological inoculant for both protection of plant against bacterial and viral pathogens and enhancement of plant growth.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.229-237
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• 2018

Medical silicone tubes are generally used as implants for the treatment of nasolacrimal duct stenosis. However, side effects such as allergic reactions and bacterial infections have been reported following the silicone tube insertion, which cause surgical failure. These drawbacks can be overcome by modifying the silicone tube surface using a functional coating. Here, we report a biocompatible and superhydrophilic surface coating based on a polysaccharide multilayer nanofilm, which can load and release antibacterial and anti-inflammatory agents. The nanofilm is composed of carboxymethylcellulose (CMC) and chitosan (CHI), and fabricated by layer-by-layer (LbL) assembly. The LbL-assembled CMC/CHI multilayer films exhibited superhydrophilic properties, owing to the rough and porous structure obtained by a crosslinking process. The surface coated with the superhydrophilic CMC/CHI multilayer film initially exhibited antibacterial activity by preventing the adhesion of bacteria, followed by further enhanced antibacterial effects upon releasing the loaded antibacterial agent. In addition, inflammatory cytokine assays demonstrated the ability of the coating to deliver anti-inflammatory agents. The versatile nanocoating endows the surface with anti-adhesion and drug-delivery capabilities, with potential applications in the biomedical field. Therefore, we attempted to coat the nanofilm on the surface of an ophthalmic silicone tube to produce a multifunctional tube suitable for patient-specific treatment.

• Journal of Radiation Industry
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• v.4 no.4
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• pp.373-379
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• 2010

Cellulose, chitin, chitosan and hyaluronic acid are well known as polysaccharides. These polysaccharides have many effects on cell growth and differentiation. Cell activation increases with increasing the polysaccharides concentration. In this study, gelatin scaffold containing microorganism fermented cellulose, citrus gel were prepared by using irradiation technique. Physical properties of the scaffolds were investigated as a function of the concentrations of gelatin and citrus gel and the cell attachment, cell morphology and inflammation of the scaffolds also were characterized for regeneration of skin tissue.

• Advances in nano research
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• v.4 no.1
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• pp.1-14
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• 2016

Superparamagnetic iron oxide nanoparticles (Nps), composed of magnetite, $Fe_3O_4$, or maghemite, ${\gamma}-Fe_2O_3$, core and biocompatible polymer shell, such as dextran or chitozan, have recently found wide applications in magnetic resonance imaging, contrast enhancement and hyperthermia therapy. For different diagnostic and therapeutic applications, current attempt is focusing on the synthesis and biomedical applications of various ferrite Nps, such as $CoFe_2O_4$ and $MnFe_2O_4$, differing from iron oxide Nps in charge, surface chemistry and magnetic properties. This study is focused on the synthesis of manganese ferrite, $MnFe_2O_4$, Nps by most commonly used chemical way pursuing better control of their size, purity and magnetic properties. Co-precipitation syntheses were performed using aqueous alkaline solutions of Mn(II) and Fe(III) salts and NaOH within a wide pH range using various hydrothermal treatment regimes. Different additives, such as citric acid, cysteine, glicine, polyetylene glycol, triethanolamine, chitosan, etc., were tested on purpose to obtain good yield of pure phase and monodispersed Nps with average size of ${\leq}20nm$. Transmission electron microscopy (TEM), X-ray diffraction, energy dispersive X-ray spectroscopy (EDX), $M\ddot{o}ssbauer$ spectroscopy down to cryogenic temperatures, magnetic measurements and inductively coupled plasma mass spectrometry were employed in this study.

• Journal of Microbiology and Biotechnology
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• v.31 no.10
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• pp.1446-1454
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• 2021

Herein, we cloned and expressed an endo-β-1,4-glucanase gene (celA1805) from Bacillus subtilis B111 in Escherichia coli. The recombinant celA1805 contains a glycosyl hydrolase (GH) family 8 domain and shared 76.8% identity with endo-1,4-β-glucanase from Bacillus sp. KSM-330. Results showed that the optimal pH and temperature of celA1805 were 6.0 and 50℃, respectively, and it was stable at pH 3-9 and temperature ≤50℃. Metal ions slightly affected enzyme activity, but chemical agents generally inhibited enzyme activity. Moreover, celA1805 showed a wide substrate specificity to CMC, barley β-glucan, lichenin, chitosan, PASC and avicel. The K_m and V_max values of celA1805 were 1.78 mg/ml and 50.09 µmol/min/mg. When incubated with cellooligosaccharides ranging from cellotriose to cellopentose, celA1805 mainly hydrolyzed cellotetrose (G4) and cellopentose (G5) to cellose (G2) and cellotriose (G3), but hardly hydrolyzed cellotriose. The concentrations of reducing sugars saccharified by celA1805 from wheat straw, rape straw, rice straw, peanut straw, and corn straw were increased by 0.21, 0.51, 0.26, 0.36, and 0.66 mg/ml, respectively. The results obtained in this study suggest potential applications of celA1805 in biomass saccharification.

• Korean Journal of Veterinary Service
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• v.44 no.3
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• pp.141-148
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• 2021

The objective of this research was to evaluate the immune response to Salmonella Gallinarum experimentally infected layers fed with Guanosine 5'-monophosphate-chelated calcium and iron feed additives. Hy-Line brown, 34 week-olds layers were assigned to 3 groups; Group 1: basal diet feed, Group 2 (CaFe-GMP): basal diet feed mixed with chelated calcium and iron, and Group 3 (Fe-OCHT): basal diet feed mixed with chitosan for 4 weeks. There were challenged with 1.0×10⁸ CFU/mL of the cultured Salmonella Gallinarum (SG) by oral administration on 28th feeding days. After SG challenge, Flow cytometric profiles showed that the CD4+/CD8+ T lymphocyte activation of Group 2 was much higher than Group 1 and Group 3 (P<0.05). In addition, the levels of interleukin-2 (13.37 mg/dl) and interferon-γ (2.35 mg/dl) in Group 2 were higher than Group 1 and Group 2. Populations of Lactic acid bacteria (3.5×10¹⁰ CFU/g) from cecum was highest observed in group 2. Re-isolation of SG from cecum in group 2 (8×10⁵ CFU/g) was lower than group 1 (1.83×10¹⁰ CFU/g). The result of this study demonstrated that CaFe-GMP feed additive may be one of the potential candidates to control salmonellosis and functional feeds in layers.

• Journal of Microbiology and Biotechnology
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• v.29 no.5
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• pp.721-730
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• 2019

The probiotic Lactobacillus acidophilus KBL409 was encapsulated with alginate (Al) and alginate-chitosan (Al/Chi) through extrusion method. The sizes and zeta potentials of microspheres were measured to confirm encapsulation. To evaluate the protective effect of microspheres against gastrointestinal fluids, all the samples were exposed to simulated gastric fluids (SGFs, pH 1.5) at $37^{\circ}C$ for 1 or 2 h, followed by incubation with simulated intestinal fluids (SIFs, pH 6.5) for 2 h. The mucoadhesive ability of microspheres was evaluated using the intestinal epithelial cell line HT29-MTX. To extend the shelf-life of probiotics, lyoprotectants such as disaccharide and polysaccharide were mixed with free or encapsulated cells during the freeze-drying process. The size of the microspheres demonstrated a narrow distribution, while the zeta potentials of Al and Al/Chi-microspheres were $-17.9{\pm}2.3$ and $20.4{\pm}2.6mV$, respectively. Among all the samples, Al/Chi-encapsulated cells showed the highest survival rate even after exposure to SGF and SIF. The mucoadhesive abilities of Al and Al/Chi-microspheres were higher than 94%, whereas the free L. acidophilus showed 88.1% mucoadhesion. Ten percent of sucrose showed over 80% survival rate in free or encapsulated cells. Therefore, L. acidophilus encapsulated with Al and Al/Chi-microspheres showed higher survival rates after exposure to the gastrointestinal tract and better mucoadhesive abilities than the free cells. Also, sucrose showed the highest protective effect of L. acidophilus during the freeze-drying process.