• Journal of Sensor Science and Technology
• /
• v.15 no.4
• /
• pp.237-244
• /
• 2006

Atomic force microscope (AFM) has become a common tool for the structural and physical studies of biological macromolecules, mainly because it provides the ability to perform experiments with samples in a buffer solution. In this study, structure of proteins and nucleic acids has been studied in their physiological environment that allows native intermolecular complexes to be formed. Cr and Au were deposited on p-Si (100) substrate by thermal evaporation method in sequence with the thickness of $200{\AA}$ and $500{\AA}$, respectively, since Au is adequate for immobilizing biomolecules by forming a self-assembled monolayer (SAM) with semiconductor-based biosensors. The SAM, streptavidin and biotin interacted each other with their specific binding energy and their adsorption was analyzed using the Bio-AFM both in a solution and under air environment. A silicon nitride tip was used as a contact tip of Bio-AFM measurement in a solution and an antimony doped silicon tip as a tapping tip under air environment. Actual morphology could also be obtained by 3-dimensional AFM images. The length and agglomerate size of biomolecules was measured in stages. Furthermore, $R_{a}$ (average of surface roughness) and $R_{ms}$ (mean square of surface roughness) and surface density for the adsorbed surface were also calculated from the AFM image.

• Korean Journal of Microbiology
• /
• v.16 no.4
• /
• pp.170-179
• /
• 1978

By the successive enrichment culture, more than 250 methanol-utilizing bacteria were isolated from various samples such as soil, waste water and sewage. Two strains of which were selected and tentatively identified as Acinetobacter sp. and Pseudomonas sp. experiments were carried out to determine the growth conditions for the higher biomass yield and to demonstrate the difference to protein composition dependent upon carbon sources of these two species. the results were as follows ; 1. the optimum pH was determined as 8 in the both species. The optimum temperature in Acinetobacter sp. was $25^{\circ}C{\sim}30^{\circ}C$ and pseudomonas sp. was $30^{\circ}C-35^{\circ}C$. The optimum initial concentration of mthanol was determined as 1-2% in Acinetobacter sp. and 2-3% in pseudomonas sp. 2. The optimum concnetrations of nitrogen source, micro-elements, and vitamins such as biotin and thiamine-HCl in Acnetobactar sp. were 1g $(NH_4)_3SO4,\;1{\sim}3mg\;Mn^{++},\;4mg\;Fe^{++},\;10{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine-HCl per liter medium. In the Pseudomonas sp., 2g $(NH_4)_3SO4,\;1mg\;Mn^{++},\;trace\;amounts\;of\;Fe^{++},\;5{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine HCl per liter were effective. Maximum biomass yield was 2.5g/l in Acinetobacter sp. and 4.8g/l in Pseudomonas sp. 3. Protein composition of the two strains exhibited that alkai-labile protein was higher than alkali-stable protein. In Pseudomonas sp., the contents of acid soluble fraction and alkali-stable protein of the cells grown in the methanol medium were higher than in sucrose medium. On the other hand, in Acinetobacter sp., alkalilabile protein of the cells grown in sucrose medium was higher than in methanol medium.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.9 no.3
• /
• pp.166-170
• /
• 2004

Gluconobacter oxydans that produces the cellulose was isolated. In order to confirm the chemical features of cellulose, various spectrophtometeric analysis were carried out using electron microscopy, X-ray diffractogram, and CP/MAS $\^$13/C NMR. The purified cellulose was found to be identical to that of Acetobacter xylinum. For effective production of cellulose, the various carbon and nitrogen sources, mixture of calcium and magnesium ions, and biotin concentration were investigated in flask cultures. Among the various carbon sources, glucose and sucrose were found to be best for the production of cellulose, with maximum concentration of 2.41 g/L obtained when a mixture of 10 g/L of each glucose and sucrose were used. With regard to the nitrogen sources, when 20 g/L of yeast extract was used, the maximum concentration of bacterial cellulose was reached. The concentration of cellulose was increased with mixture of 2 mM of each Ca$\^$2+/ and Mg$\^$2+/. The optimum biotin concentration for the production of cellulose was in the range of 15 to 20mg/L. At higher biotin concentration (25-35mg/L). the bacterial cellulose production was lower.

• Korean Journal of Microbiology
• /
• v.32 no.2
• /
• pp.97-101
• /
• 1994

Fifteen strains of the nitrogen fixer Axospirillum were isolated from the rhizosphere of rice collected from Kyonggi-do and Chungcheongnam in Korea. They had strong acetylene-reducing activity of 400 of 900 nmol $C_2H_4$ per hour vial had a similar morphology in succinate-malate medium: vibrioid cells having a diameter of 1.0 ${\mu}m$ and a monopolar single flagellum in liquid media. According to their physiological and morphological characteristics, they were divided into two distinct groups, group I and group II. Group I strain were, unlike group II, distinguished by their ability to use glucose as a sole carbon source in nitrogen-free medium, requirement for biotin, and formation of wider, longer, and S-shaped cells in semisolid nitrogen-free malate medium. On the basis of their characteristics, strains belonging to group I were identified as Azospirillum lipoferum, while those belonging to group II were identified as Azospirillum brasilense.

• Analytical Science and Technology
• /
• v.9 no.1
• /
• pp.84-90
• /
• 1996

New hepatocyte specific copolymers, that have oligosaccharide and biotin residue on the side chain of styrene, were designed and synthesized to use as a multifunctional recognition. In order to measure initial adhesion efficiency, 1mL of copolymer solutions (0.01%, w/v) such as p(VLA-co-VBA) 90 : 10, p(VLA-co-VBA) 80 : 10 and PYLA as a standard were added to polystyrene petri dish, respectively. In the absence and presence of serum, hepatocyte solution of rat by method of Seglen was added. After 60 min, adhesion efficiency was 70%, that is similar to those of the absence of serum. Aggregation capacity between biotin residue in p(VLA-co-VBA) 70 : 30 and avidin was measured by using UV-transmittance.

• Biomedical Science Letters
• /
• v.2 no.2
• /
• pp.275-282
• /
• 1996

The authors inquired into what reactions comprise the response of mice(as a model) CD3, CD4 and CD8 monoclonal antibodies in spleen tissue when injected intraperitoneally by antigens of Clonorchis sinensis. The author is objective was focused on investigating the property of cellular immunity for liver fluke. In particular, the results of having examined the phenotype of the tissue of spleen were revealed as follows: a certain length of time after having been intraperitoneally injected with antigens of Clonorchis sinensis and Freund's adjuvant, the tissue of spleen was embedded and immunohistochemically stained by the avidin-biotin complex method. A strong reaction in response to CD3, while a feeble reaction resulted from CD4 and CD8. The tissue region showed a positive reaction to all antibodies, especially from capsules, vascular areas, white pulps and membrane of blood cells.

• Microbiology and Biotechnology Letters
• /
• v.2 no.3
• /
• pp.141-147
• /
• 1974

The cultural conditions for L-glutamate production were investigated using Brevibacterium flavum nov. sp. D2209B, the most productive strain among 5 strains reported in preceeding paper. A temperature of 3$0^{\circ}C$ and a medium volume of 30 ml per 500-flask were selected as standard culture conditions. And the following results were obtained. 1. When the concentration of acetate in the medium was below 30 g per litre, the maximum amount of L-glutamate was accumulated. 2. KH$_2$PO$_4$, MgSO$_4$, FeCI$_3$ and MnCI$_2$ were required for the L-glutamate poduction, but the concentration of those inorganic salts little effected. 3. Signifcant amount of L-glutamate was accutnulated in the limited biotin concentration less than 0.3 ug per litre. 4. The addition of malic acid or succinic acid enhanced the accumulation. 5. The L-glutamate accumulation was related to the incubation time of seed; the amount of L-glutamate accumulated was maximum by inoculating 16-20 hour incubated seed. 6. In the medium containing sufficient amount of biotin for growth, L-glutamate accumulation was stimulated by the addition of penicillin at appropreate time during incubation.

• Biomedical Science Letters
• /
• v.2 no.2
• /
• pp.257-265
• /
• 1996

Simple stain and electron microscopic in situ hybridization is studied and applied for the identification of rabbit haemorrhagic disease viral RNA in a unicrylated preparation of the liver after innoculation of rabbit haemorrhagic disease virus. Hybridization for detection of viral RNA in unicryl embedded tissues using complementary 84 bases oligonucleotide probe labelled by biotin CE-phosphoramidite compared with 4717∼4800 sequences of rabbit haemorrhagic disease virus, modified hybridization protocol and antibiotin antibody-l0nm gold as signal marker. The best results were obtained in 0.02% glutaraldehyde, Unicryl resin cell block, biotinylated oligonucleotide probes, antibiotin-l0nm gold. In this report, RHD viral RNA was distributed widely within the mitochondria and nucleus of liver cell by electron microscopic in situ hybridization. In situ hybridization has become a standard method for localizing DNA or RNA sequences in tissue or celt preparation. In situ hybridization is detected the virus genome in the cells and tissue as specifically compared with others nucleic acid hybridization method.

• Biomedical Science Letters
• /
• v.2 no.2
• /
• pp.249-255
• /
• 1996

In this paper, a in situ hybridization(ISH) has been used to investigate the yield of viral RNA expression from each organ tissues. It is studied to establish a rapidly, specific diagnostic method detecting rabbit haemorrhagic disease virus(RHDV) RNA in 10% formalin-fixed, paraffin-em-bedded tissues of naturally RHDV-infected rabbits using oligonucleotide probe to be made by RHDV total sequences. Biotin was used as the oligonucleotide probe marker. in situ hybridization is detected the virus genome in the cells and tissue as specifically compared with others nucleic acid hybridization method. All ISH procedure of RHDV were completed to Mi-croProbe$^{TM}$ capillary action system within 1-2 hours. In this report, RHDV was distributed widely in the cytoplasm of liver cell and the cortex of kidney but lung tissue and medulla of kidney were showed to positive reaction at locally. Although not entirely free of technical limitations, nucleic acid identification holds advantages over other diagnostic tests, including exquisite sensitivity, specificity, interchangeability and speed. It is expected that, in the immediate future viral nucleic acid detection will be a prominent part of the methods used in histopathology.

• Microbiology and Biotechnology Letters
• /
• v.3 no.3
• /
• pp.147-156
• /
• 1975

The possibility of using tapioca pellets as a raw material in glutanmic acid fermentation by Microcuccus glutamicus is shown. The ground pellets were diluted with water to 20％ solid level and treated with $\alpha$-anylase prepared from a thermophilic Actinomycetes strain culture for 90 min at 85$^{\circ}C$ under pH 6.0. The liquefied solution was further saccharified with commercial glucoamylase for 36 hours under the reaction conditions of 55$^{\circ}C$ and pH 5.0. The inhibitory effect of excess biotin content, 16 $\mu\textrm{g}$ Per liter of the hydrolzate, could be reduced effectively by adding 10 IU of penicillin per ml of the medium after five hours of the fermentation. The maximum glutamic acid yield of 38.5 g/l was obtained after 60 hours of shaking culture at 28-3$0^{\circ}C$.