• Geomechanics and Engineering
• /
• v.5 no.2
• /
• pp.87-97
• /
• 2013

In this paper, a novel fibrous material known as axially reinforced braided composite rods (BCRs) have been developed for reinforcement of soils. These innovative materials consist of an axial reinforcement system, comprised of longitudinally oriented core fibres, which is responsible for mechanical performance and, a braided cover, which gives a ribbed surface texture for better interfacial interactions with soils. BCRs were produced using both thermosetting (unsaturated polyester) and thermoplastic (polypropylene) matrices and synthetic (carbon, glass, HT polyethylene), as well as natural (sisal) core fibres. BCRs were characterized for tensile properties and the influence of core fibres was studied. Moreover, BCRs containing carbon fibre in the core composition were characterized for piezoresistivity and strain sensing properties under flexural deformation. According to the experimental results, the developed braided composites showed tailorable and wide range of mechanical properties, depending on the core fibres and exhibited very good strain sensing behavior.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.374-377
• /
• 2001

On the basis of high-osmotic tolerance and xylitol productivity, it was isolated a novel strain from soil of rice field. An isolated strain was tentatively designated as Candida sp. HY200, deduced from the systematic approaches of bacterial identification by Biolog $Microlog^{TM}$ and, revealed an interesting ability of flocculation during the cultivation. With respect to the osmotic-tolerance and flocculation ability, experiment was carried out to investigate the production of xylitol in high xylose concentration. When xylose concentration was 260 g/L, it was obtained 205 g/L xylitol with 79% of yield and 2.14 g/L ${\cdot}$ h of productivity Consequently, We convinced that Candida sp. HY200 stands a very favorable comparison with C. tropicalis.

• Korean Journal of Microbiology
• /
• v.24 no.3
• /
• pp.295-301
• /
• 1986

The bacteria, which were capable of producing ${\beta}-1$, 3-glucanase inducibly by utilizing cell wall of Aspergillus fumigatus as a sole carbon source, were isolated from soil in the campus of Kyungpook National University. Among them, the strain which produced the enzyme excellently was selected and identified to be Pseudomonas stutzeri KF 13 by morphological, cultural and physiological examination. The optimal conditions for the enzyme production from Pseudomonas stutzeri KF 13 were investigated. the enzyme production was reached maximum state shen the broth cultured for 72hr at $30^{\circ}C$. And the enzyme showed the highest activity in the medium containing 3.5% cell wall as an inducer, 15% yeast autolysate as a nitrogen source and 0.05% $MnSO_4$ at pH 7.5.

• Korean Journal of Microbiology
• /
• v.20 no.3
• /
• pp.105-112
• /
• 1982

The strain of Aspergillus, 6368A, producing acid protease showing high activity was isolated from soil, as a result of wide research about mold group. This strain was identified as a species of Aspergillus tubingensis by the investigation of morphological characteristics. The change of the enzyme production under the various media and culture condition was also studied. The optimum pH and stability of crude acid protease are 2.5, 2.0~4.5 and the optimum temeprature and thermal inactivation waas shown $50^{\circ}C,\;55^{\circ}C$, respectively. From the result of the study on the effects of metal ions, it was found that $MnCl_2,\;CoCl_2,\;CuCl_2,\;SrCl_2,\;and\;NiCl_2$ slightly increased the enzyme activity, on the other hand $ZnCl_2,\;CaCl_2,\;MgCl_2,\;SLS,\;and\;KMnO_4$ decreased it.

• Journal of Microbiology
• /
• v.40 no.1
• /
• pp.38-42
• /
• 2002

The strain KKI isolated from soil contaminated with polycyclic aromatic hydrocarbons was identified as Pseundomonas sp. based on analyses by MIDI and Biolog Identification System. Cellular and physiological responses of strain KKI to two-ring polycyclic aromatic hydrocarbon, naphthalene were evaluated using radiorespirometry, PLFAs and sequence analysis of Rieske-type iron sulfur center of dioxygenase. KKI was found to be able to rapidly mineralize naphthalene. Notably, KKI cells pregrown on phenanthrene were able to mineralize naphthalene much more rapidly than naphthalenepregrown cells. The total cellular fatty acids of KKI were comprised of eleven C-even and two C-odd fatty acids (fatty acids < 0.2% in abundance were not considered in this calculation). Lipids 12:0 2OH, 12:03 OH, 16:0, 18:1 6c, 18:0 increased for naphthalene-exposed cells, while lipids 18:1 7c1/15:0 ism 2OH, 17:0 cyclo, 18:1 7c, 19:0 cyclo decreased. Data from Northern hybridization using a naphthalene dixoygenase gene fragment cloned out from KKI as a probe provided the information that naphthalene dioxygenase gene was more highly expressed in cells grown on phenanthrene than naphthalene.

• Korean Journal of Microbiology
• /
• v.33 no.1
• /
• pp.38-42
• /
• 1997

For the purpose of obtaining microorganisms producing high amount of erythritol, the screening test was carried out. Productivity of erythritol was analyzed by paper chromatography and HPLC' methods. Among more than two hundred isolates, one strain(KJX1) was selected as an erythritol prtducer from thc soil of corn shock. The isolated strain was identified as Pmicilliurn sp. KJ81 from the morphological and physiological characteristics. Penicillium sp. KJ81 showed white to green colony color, two- to three-stage branching conidiophcvc and flask-shaped phialides.

• Microbiology and Biotechnology Letters
• /
• v.6 no.4
• /
• pp.161-165
• /
• 1978

Out of 11 organic acid producing strains isolated from fruits, soil, and air, one strain was selected for the study of the citric acid fermentation using Sakaguchi's medium. The organism was identified as Aspergillus niger. When Asp.niger was shaked at 3$0^{\circ}C$ in a cotton plugged 500 mι Erlenmeyer flask with 100 ml of Sakagnchi's medium containing 10% of glucose (Difco), 0.6% of peptone, and mineral, citric acid were produced at the level of 17 gram per liter in 14 days. The citric acid was also produced at the level of 35 gram per liter after the improvements of Sakaguchi's medium-the adaptation, peptone addition, aeration, methanol addition, and glucose addition.

• Microbiology and Biotechnology Letters
• /
• v.19 no.2
• /
• pp.122-127
• /
• 1991

A bacterial strain NO. 32 which produced thermostable ${\alpha}$-amylase was isolated from soil and identified to genus of Bacillus. To enhance ${\alpha}$-amylase productivity, a successive mutation of Bacillus sp. No. 32 was attempted with treatment of N-methyl-N'-nitro-N-nitrosoguanidine (NTG). The resulting mutant, Bacillus sp. No. 32H417, which is risistant to refampicin and deficient in spore formation, produced about 90-fold high level of ${\alpha}$-amylase when compared with parental strain. The properties of the enzyme for thermostability were investigated. The optimal temperature and pH for enzyme reaction were 95$^{\circ}C$ and pH6.5, respectively, in the presence of 0.3mM $Ca^{2+}$ as an effective stabilizer.

• The Plant Pathology Journal
• /
• v.27 no.3
• /
• pp.242-248
• /
• 2011

Several soil bacteria were found to degrade N-Acylhomoserine lactones (NAHLs), thereby interfering with the bacterial quorum sensing system. In this research, fifteen strains of NAHL degrading rhizobacteria were isolated from potato rhizosphere. Based on phenotypic characteristics and 16S rDNA sequence analyses, the strains were identified as members of genera Bacillus, Streptomyces, Arthrobacter, Pseudomonas and Mesorhizobium. All tested isolates were capable to degrade both synthetic and natural NAHL produced by Pectobacterium carotovorum subsp. carotovorum (Pcc) strain EMPCC. In quorum quenching experiments selected isolates, especially Mesorhizobium sp., were markedly reduced the pathogenicity of Pcc strain EMPCC in potato tubers and totally suppressed tissue maceration on potato tubers. These led to consider the latter as a useful biocontrol agent against Pectobacterium spp.

• Journal of Microbiology and Biotechnology
• /
• v.8 no.6
• /
• pp.645-649
• /
• 1998

A glycolipid type of biosurfactants was obtained from a strain which had been isolated from soil. The cell was identified as Pseudomonas aeruginosa from taxonomic characteristics and was designated as YPJ80. Thin layer chromatography and deoxyhexose detection tests were done to verify the type of biosurfactant. Critical micelle concentration (CMC) of the surfactant was observed to be 50 ppm and the minimum surface tension was 30.1 mN/m. As an emulsifier, YPJ80 biosurfactant was superior to emulsan in the emulsification of crude Arabian light oil.