• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.22-32
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• 2000

This paper describes the development of a precision 3-component load cell with plate beams which may be used for measuring forces Fx, Fy and moment Mz simultaneously in industry. The equations to predict the bending strains on the surface of the beams under forces or moment are derived, the attachment location of strain gages of each sensor is determined, and 3-component load cell is carried out. It reveals that the rated strain calculated from the derived equations are good agreement with the results from Finite Element Method analysis.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.121-126
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• 2004

Comamonas sp. strain DJ-12 is a 4-chlobiphenyl(4CB)-degrading bacterium that was reidentified from Pseudomonas sp. DJ-12. The genomic DNA was isolated from the strain DJ-12 and amplified by PCR with primers for cloning pcbABCD genes responsible for degradation of 4CB. The amino acid sequences deduced from the nucleotide sequences of pcbA1, pcbA2, pcbA3, pcbA4, pcbB, pcbC2, and pcbD2 genes showed 91, 87, 99, 87, 97, 90 and 87％ homologies with those of Pseudomonas sp. KKS102, respectively. The pcbC1D1 genes that are involved in the degradation of (4-chloro)1,2-dihydroxybiphenyl produced from 4CB by pcbAB gene products were previously reported in the recombinant plasmid pCU1 from Pseudomonas sp. DJ-12. However, the pcbC2D2 genes in the plasmid pCT4 and pCT5 cloned from Comamonas sp. DJ-12 in this study showed 51 and 62％ homologies with those of pcbC1D1 in their nucleotide sequences. The pcbC1D1 and pcbC2D2 genes were found by Southern hybridization to be located at different loci on the chromosome of DJ-12 strain. These results indicate that Comamonas sp. strain DJ-12 has two different sets of pcbCD genes responsible for deg-radation of (4-chloro)1,2-dihydroxybiphenyl.

• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.322-326
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• 1994

Bacillus thuringiensis strain BT-14 was isolated from alfalfa dust in Korea. The strain BT-14 produced one bipyramidal crystal and one spore in the cell. The biochemical characteristics of the strain BT-14 were similar to those of Bacillus thuringiensis subsp. kurstaki HD-l. Examination of its antibiotic resistance revealed that while the strain BT-14 was less resistant than BTK HD-l to ampicillin, gentamycin, neomycin and tobramycin, it was more resistant to amikacin than BTK HD-l. The $\delta$-endotoxin crystal of strain BT-14 consisted of a single protein with a high molecular weight of ca 135 KD on a 10% SDS-PACE. The strain BT-14 contained at least nine different plasmids with sizes of 2.9, 5.3, 5.8, 6.2, 9.4, 15.1, 18.1, 23.1 and 79 Kb. In insect bioassay, the isolated strain BT-14 showed lethality of 67% against Plutella xylostella larvae at dilution of 5$\times$$l0^{-4}$ (5$\times$l0 to 3$\times$$l0^2$ spores/ml), which is, almost equivalent to that of BTK HD-l.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.1057-1062
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• 2004

The entomopathogenic bacterium Bacillus thuringiensis is the most widely used biopesticide. Insecticidal proteins, coded by genes located in plasmids, form typical parasporal, crystalline inclusions during sporulation. We isolated a Bacillus thuringiensis strain having insecticidal activity against larvae of the house fly (M. domestica) from the soils at a pig farm in Korea, and named it Bacillus thuringiensis SM. The culture filtrate from Bacillus thuringiensis SM showed strong lethality (83.3%) against M. domestica larvae. The parasporal crystal is enclosed within the spores' outermost envelope, as determined by transmission electron microscopy, and exhibited a bipyramidal form. The crystal proteins of strain SM consisted of five proteins with molecular weights of approximately ~130, ~80, ~68, ~42, and ~27 kDa on a 10% SDS-PAGE (major band, a size characteristic of Cry protein). Examination of antibiotic resistance revealed that the strain SM showed multiple resistant. The strain SM had at least three different plasmids with sizes of 6.6, 9.3, and 54 kb. Polymerase chain reactions (PCRs) revealed the presence of cry1, cry4A2, and cry11A1 genes in the strain SM. The cry1 gene profile of the strain SM appeared in the three respective products of 487 bp [cry1A(c)], 414 bp [cry1D], and 238 bp [cry1A(b)]. However, the strain SM has not shown the cry4A2 md cry11A1 genes. In in vivo toxicity assays, the strain SM showed high toxicity on fly larvae (M. domestic) [with $LC_{50}$ of 4.2 mg/ml, $LC_{90}$ of 8.2 mg/ml].

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1266-1272
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• 2019

A bacterial strain, labeled $UR11^T$, was isolated from green alga Ulva pertusa collected from Jeju Island, Korea. $UR11^T$ was identified as a gram-negative, rod-shaped, motile by gliding and aerobic bacterial strain with yellow colonies on R2A plates. The strain $UR11^T$ grew over at a temperature range of $10^{\circ}C$ to $30^{\circ}C$ (optimally at $25^{\circ}C$), a pH range of 6.0-11 (optimally at pH 7.0) and a Nacl range of 0.5-5% Nacl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain $UR11^T$ was a member of the genus Flavobacterium. Strain $UR11^T$ shared close similarity with F. jejuensis $EC11^T$ (98.0%) F. jumunjinense $HME7102^T$ (96.1%), F. haoranii $LQY-7^T$ (95.3%), F. dongtanense $LW30^T$ (95.1%), and F. ahnfeltiae 10Alg $130^T$(94.9%). The major fatty acids (>5%) were $iso-C_{15:0}$ (33.9%), $iso-C_{15:1}$ G (12.4%), $iso-C_{17:0}$ 3-OH (9.0%), $isoC_{16:0}$ (7.0%) and $iso-C_{15:0}$ 3-OH (6.3%). The major polar lipids were phosphatidylethanolamine, seven unknown aminolipids, two unknown aminopolarlipids and two unknown lipids. DNA-DNA hybridization value was 58% at strain $UR11^T$ with F. jejuensis $EC11^T$. Based on phenotypic, chemotaxonomic and phylogenetic evidence, strain $UR11^T$ represents a novel species of the genus Flavobacterium, for which the name Flavobacterium jocheonensis sp. nov. is proposed. The type strain is Flavobacterium jocheonensis is $UR11^T$ (=KCTC $52377^T$ =JCM $31512^T$).

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1536-1541
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• 2018

A yellowish, flexirubin-pigment-producing strain $I3-3^T$ was isolated from river water in Iksan, the Republic of Korea. The strain was gram-negative, aerobic, non-motile, showed catalase and oxidase activities, and could grow at a temperature range of $10-35^{\circ}C$, pH 5.0-10 and 0-2.0% (w/v) of NaCl. The major fatty acids were iso-$C_{15:0}$, iso-$C_{17:0}$ 3-OH and summed feature 3 (comprising $C_{16:1}{\omega}7c$ and/or $C_{16:1}{\omega}6c$). The isolate contained phosphatidylethanolamine, one aminolipid, and two unidentified lipids as the major polar lipids. Menaquinone-6 (MK6) was the major respiratory quinone. The G+C content of the genomic DNA of strain $I3-3^T$ was 35.6%. Comparison of the 16S rRNA gene sequence with the sequences of the closely related type strains showed highest sequence similarity of 96.95% and 96.93% to Flavobacterium nitrogenifigens $NXU-44^T$ and Flavobacterium compostarboris $15C3^T$, respectively. Based on phenotypic and phylogenetic distinctiveness, strain $I3-3^T$ is considered as a member of novel species within the genus Flavobacterium, for which Flavobacterium amnigenum sp. nov. is proposed. The type strain is $I3-3^T$ (=KCTC $52884^T$ =NBRC $112871^T$).

• Applied Biological Chemistry
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• v.39 no.1
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• pp.60-66
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• 1996

To investigate a possible application of three strains of lactic acid bacteria(strain No. 49. No. 61. No. 75) from kimchi in milk fermentation industry, the optimal condition for production of intracellular ${\beta}-galactosidase$ from Lactobacillus(L.) plantarum and its enzymatic properties were examined. The preferable carbon source of the medium for strain No. 49 in production of ${\beta}-galactosidase$ was MRS broth with 1.0% lactose instead of dextrose of pH 65. for strain No. 75 with 1.0% galactose and for strain No. 61 with 3.0% lactose at pH 7.5, respectively. The maximum enzyme production from strain No. 49, No. 75 was observed after 48 hours culture at $30^{\circ}C$ in a medium containing the appropriate carbon source, from strain No. 61 after 48 hours culture at room temperature. The optimum temperature for ${\beta}-galactosidase$ activity from L. plantarum was $60^{\circ}C$ for strain No. 49, $37^{\circ}C$ for strain No. 61 and $50^{\circ}C$ for strain No. 75, respectively. The heat stability of enzyme activities for all three strains remained 90% at $45^{\circ}C$. The optimal pH was pH 6.5 and enzyme activities were most stable at pH for all three bacteria.

• Steel and Composite Structures
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• v.30 no.6
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• pp.551-565
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• 2019

A total of 36 carbon steel and stainless steel bolted connections subjected to shear loading at different strain rates was experimentally investigated. The connection specimens were fabricated from carbon steel grades 1.20 mm G500 and 1.90 mm G450, as well as cold-formed stainless steel types EN 1.4301 and EN 1.4162 with nominal thickness 1.50 mm. The connection tests were conducted by displacement control test method. The strain rates of 10 mm/min and 20 mm/min were used. Structural behaviour of the connection specimens tested at different strain rates was investigated in terms of ultimate load, elongation corresponding to ultimate load and failure mode. Generally, it is shown that the higher strain rate on the bolted connection specimens, the higher ultimate load was obtained. The ultimate loads were averagely 2-6% higher, while the corresponding elongations were averagely 8-9% higher for the test results obtained from the strain rate of 20 mm/min compared with those obtained from the lower strain rates (1.0 mm/min for carbon steel and 1.5 mm/min for stainless steel). The connection specimens were generally failed in plate bearing of the carbon steel and stainless steel. It is shown that increasing the strain rate up to 20 mm/min generally has no effect on the bearing failure mode of the carbon steel and stainless steel bolted connections. The test strengths and failure modes were compared with the results predicted by the bolted connection design rules in international design specifications, including the Australian/New Zealand Standard (AS/NZS4600 2018), Eurocode 3 - Part 1.3 (EC3-1.3 2006) and North American Specification (AISI S100 2016) for cold-formed carbon steel structures as well as the American Specification (ASCE 2002), AS/NZS4673 (2001) and Eurocode 3 - Part 1.4 (EC3-1.4 2015) for stainless steel structures. It is shown that the AS/NZS4600 (2018), EC3-1.3 (2006) and AISI S100 (2016) generally provide conservative predictions for the carbon steel bolted connections. Both the ASCE (2002) and the EC3-1.4 (2015) provide conservative predictions for the stainless steel bolted connections. The EC3-1.3 (2006) generally provided more accurate predictions of failure mode for carbon steel bolted connections than the AS/NZS4600 (2018) and the AISI S100 (2016). The failure modes of stainless steel bolted connections predicted by the EC3-1.4 (2015) are more consistent with the test results compared with those predicted by the ASCE (2002).

• KSBB Journal
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• v.31 no.1
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• pp.58-65
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• 2016

In this study, Arthrobacter scleromae SYE-3, which was isolated from indigenous plant in a subtropical region, Neigeria, with plant growth promoting activity was evaluated to determine the optimal culture condition. A bacterial strain SYE-3 had the IAA productivity ($89.15{\pm}0.36mg/L$) and ACC deaminase activity ($0.20{\pm}0.06$ at 72 hours). Also, optimal culture conditions such as temperature and pH of strain SYE-3 were $20^{\circ}C$ and 10 in LB medium, respectively. Strain SYE-3 had up to 3% salt tolerance in the LB medium. Plant growth promoting ability of strain SYE-3 using yam (Dioscorea japonica Thunb.) was evaluated. As a result, strain SYE-3 had showed very powerful effect on the increase of the shoot length and root biomass of yam (190.0% and 282.41% increase for 112 days, respectively). These results indicated that Arthrobacter scleromae SYE-3 can serve as a promising microbial resource for the biofertilizers of subtropical crops.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1327-1336
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• 2014

Bacillus amyloliquefaciens strain NJZJSB3 has shown antagonism of several phytopathogens in vitro, especially Sclerotinia sclerotiorum. Both the broth culture and cell suspension of strain NJZJSB3 could completely protect the detached leaves of canola (Brassica napus) from S. sclerotiorum infection. In pot experiments, the application of strain NJZJSB3 cell suspension ($10^8CFU/ml$) decreased the disease incidence by 83.3%, a result similar to commercially available fungicide (Dimetachlone). In order to investigate the potential biocontrol mechanisms of strain NJZJSB3, the nonvolatile antifungal compounds it produces were identified as iturin homologs using HPLC-ESI-MS. Antifungal volatile organic compounds were identified by gas chromatography-mass spectrometry. The detected volatiles toluene, phenol, and benzothiazole showed antifungal effects against S. sclerotiorum in chemical control experiments. Strain NJZJSB3 also produced biofilm, siderophores and cell-wall-degrading enzymes (protease and ${\beta}$-1,3-glucanase). These results suggest that strain NJZJSB3 can be a tremendous potential agent for the biological control of sclerotinia stem rot.