• Food Science and Preservation
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• v.14 no.2
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• pp.194-200
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• 2007

In order to enhance the functionality and storage period of traditional fermented foods, the strain CH-14, which To enhance the quality of traditional fermented foods, and to lengthen acceptable storage periods, a bacterial strain, CH-14, showing potent enzyme activities and antibacterial capabilities, was isolated and characterize4 The bacterium wn Gram-positive, catalase-positive, oxidase-negative, formed endospores, expressed flagella, was rod-shaped, and had dimensions of 0.5 0.7m and 3.5 4.2m. The bacterium CH-14 was identified as Bacillus subtilis using Bergey's Manual of Systematic Bacteriology, Bergey's Manual of Determinative Bacteriology, and an API 50 CHL Carbohydrate Test Kit. An optimum growth medium contained 2% (w/v) cellobiose as a carbon source, a mixture of 0.5% (w/v) yeast extract and 0.5% (w/v) peptone as nitrogen sources, and 0.05% (w/v) $MgSO_4{\cdot}7H_2O$. The optimal culture temperature and the optimal initial pH were in the ranges of 30 $45^{\circ}C$ and 4.5 10.0, respectively. Maximum production of the antibacterial substance occurred after 24h of culture. The minimum inhibitory concentrations of the antibacterial substance were 5mg bacterial dry weight/mL against E. coli and P. mirabilis, and 10 mg/mL against S. aureus, S. enteritidis and V. parahaemolyticus.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.242-247
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• 2019

Biological factors (e.g. microorganism activity) in wastewater treatment plant (WWTP) play essential roles for degradation and/or removal of organic matters. In this study, to understand the microbial functional roles in WWTP, we tried to isolate and characterize a bacterial strain from activated sludge sample. Strain S16 was isolated from the activated sludge of a municipal WWTP in Daejeon metropolitan city, the Republic of Korea. The cells were a Gram-stain-positive, non-motile, facultative anaerobe, and rod-shaped. Strain S16 grew at a temperature of $15{\sim}40^{\circ}C$ (optimum, $30^{\circ}C$), with 0~9.0% (w/v) NaCl (optimum, 1.0~2.0%), and at pH 5.5~9.0 (optimum, pH 7.0~7.5). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S16 was most closely related to the unique species Miniimonas arenae NBRC $106267^T$ (99.79%, 16S rRNA gene sequence similarity) of the genus Miniimonas. The cell wall contained alanine, glutamic acid, serine, and ornithine. Although the isolation source of the type strain NBRC $106267^T$ which considered as a marine microorganism is sea sand, that of strain S16 is terrestrial environment. It might raise an ecological question for habitat transition. Therefore, comparative genome analysis will be valuable investigation for shedding light on their potential metabolic traits and genomic streamlining.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.476-486
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• 2019

Objective : The functional information of $^{11}C$-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell $GammaPlan^{(R)}$ (LGP) and also investigated clinical application of these images in metastatic brain tumors. Methods : Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors. Results : Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images. Conclusion : The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.89-94
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• 2022

Triclosan (TCS) is an antimicrobial agent used in various human personal care products against both gram-positive and gram-negative bacteria. The purpose of this study was to evaluate the presence of TCS-resistant bacteria in sewage water in Peshawar, Khyber Pakhtunkhwa (KPK), Pakistan, for the first time. TCS-supplemented Luria Bertani (LB) agar was used to isolate TCS-tolerant bacteria. A total of 17 TCS-resistant isolates were randomly selected from a large pool of bacteria that showed growth on TCS-supplemented LB agar. Based on gram staining and physiochemical characteristics, the isolated strains were identified as Salmonella typhi (n = 6), Escherichia coli (n = 4), Citrobacter freundii (n = 4), Proteus mirabilis (n = 1), Enterobacter cloacae (n = 1), and Pseudomonas aeruginosa (n = 1). The Triclosan mean minimum inhibitory concentrations (MICs) for the isolates of Salmonella typhi, Escherichia coli, Citrobacter freundii, Proteus mirabilis, Enterobacter cloacae, and Pseudomonas aeruginosa were 23.66 ㎍ ml^-1, 18.75 ㎍ ml^-1, 42 ㎍ ml^-1, 32 ㎍ ml^-1, 64 ㎍ ml^-1, and 128 ㎍ ml^-1, respectively. The antibiogram revealed that all isolates were resistant to penicillin G (100%) and linezolid (100%), followed by ampicillin (94%), tetracycline (76%), tazobactam (76%), sulbactam/cefoperazone (64%), polymyxin PB (58%), amikacin (29.41%), aztreonam (29.41%), imipenem (5%), and gentamicin (5%). This is the first known study regarding the isolation of TCS-tolerant bacteria from sewage water in Peshawar, KPK, Pakistan. It was concluded that all the TCS-resistant isolates were multidrug resistant (MDR) gram-negative rod-shaped bacteria, mostly belonging to the Enterobacteriaceae family.

• Research in Plant Disease
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• v.27 no.4
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• pp.180-186
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• 2021

Typical bacterial symptoms, water-soaking brown and black leaf spots with yellow halo, were observed on watermelon seedlings in nursery and field of Gyeongnam and Jeonnam provinces. Bacterial isolates from the lesion showed strong pathogenicity on watermelon and zucchini. One of them was rod-shaped with 4 polar flagella by observation of transmission electron microscopy. They belonged to LOPAT group 1. The phylogenical trees with nucleotide sequences of 16S rRNA and multi-locus sequencing typing with the 4 house-keeping genes (gapA, gltA, gyrB, and rpoD) of the isolates showed they were highly homologous to Pseudomonas syringae pv. syringae and grouped together with them, indicating that they were appeared as P. syringae genomospecies group 1. Morphological, physiological, and genetical characteristics of the isolates suggested they are P. syringae pv. syringae. We believe this is the first report that P. syringae pv. syringae caused leaf spot disease on watermelon in the Republic of Korea.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.188-194
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• 2023

Microbacterium elymi KUDC0405^T was isolated from the rhizosphere of Elymus tsukushiensis from the Dokdo Islands. The KUDC0405^T strain was Gram-stain-positive, non-spore forming, non-motile, and facultatively anaerobic bacteria. Strain KUDC0405^T was a rod-shaped bacterium with size dimensions of 0.3-0.4 × 0.7-0.8 ㎛. Based on 16S rRNA gene sequences, KUDC0405^T was most closely related to Microbacterium bovistercoris NEAU-LLE^T (97.8%) and Microbacterium pseudoresistens CC-5209^T (97.6%). The dDDH (digital DNA-DNA hybridization) values between KUDC0405^T and M. bovistercoris NEAU-LLE^T and M. pseudoresistens CC-5209^T were below 17.3% and 17.5%, respectively. The ANI (average nucleotide identity) values among strains KUDC0405^T, M. bovistercoris NEAU-LLE^T, and M. pseudoresistens CC-5209^T were 86.6% and 80.7%, respectively. The AAI (average amino acid identity) values were 64.66% and 64.97%, respectively, between KUDC0405^T and its closest related type strains. The genome contained 3,596 CDCs, three rRNAs, 46 tRNAs, and three non-coding RNAs (ncRNAs). The genomic DNA GC content was 70.4%. The polar lipids included diphosphatydilglycerol, glycolipid, phosphatydilglycerol, and unknown phospholipid, and the major fatty acids were anteiso-C_17:0 and iso-C_16:0. Strain KUDC0405^T contained MK-12 as the major menaquinone. Based on genotypic, phylogenetic, and phenotypic properties, strain KUDC0405^T should be considered a novel species within the genus Microbacterium, for which we propose the name M. elymi sp. nov., and the type strain as KUDC0405^T (=KCTC 49411^T, =CGMCC1.18472^T).

• Journal of Dairy Science and Biotechnology
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• v.41 no.4
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• pp.191-202
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• 2023

In this study, lactic acid bacteria (LAB) was isolated from blueberries. The isolated LAB were rod-shaped and gram-positive, as shown using gram staining. In addition, the identified bacteria showed high homology to Lactiplantibacillus argentoratensis. The culture supernatant was isolated from L. argentoratensis and its antibacterial activity against the pathogenic bacteria Salmonella and Escherichia was analyzed. Culture supernatants of L. argentoratensis significantly inhibited the growth of Salmonella. Enteritidis NCCP 16947, Salmonella Typhimurium NCCP 16960, and Salmonella. Thompson NCCP 11704. Interestingly, the higher the concentration of the culture supernatant, the more significant was the antibacterial activity. Additionally, the culture supernatant of L. argentoratensis showed significant antibacterial activity against Escherichia strains. To determine whether the antibacterial substance is stable to heat and pH, the LAB culture supernatant was heat-treated under 65℃ for 30 min, 75℃ for 15 min, 85℃ for 10 min, and 100℃ for 5 min. Measurement of antibacterial activity against pathogenic strains by adding 5% of heat-treated culture medium showed the same antibacterial activity as before heat treatment. However, in a test where the pH of the culture supernatant was adjusted to 7.0 from 3.73, no antibacterial activity was observed.

• Journal of Microbiology and Biotechnology
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• v.34 no.7
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• pp.1475-1483
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• 2024

Three Gram-stain-positive, aerobic, rod-shaped, and non-motile bacteria, labelled as W11^T, SW19^T, and YR1^T, were isolated from soil, and performed their polyphasic taxonomic investigation. The phylogenetic and 16S rRNA gene sequence analysis showed that strains W11^T, SW19^T, and YR1^T belonged to the genera Agromyces, Rathayibacter, and Nocardioides, respectively. Strain W11^T was closely affiliated with Agromyces cavernae SYSU K20354^T (98.1%), strain SW19^T showed the closest affiliation with Rathayibacter rubneri ZW T2_19^T (97.0%), and strain YR1^T was most closely related to Nocardioides marmorisolisilvae KIS18-7^T (98.0%). The genome sizes of strains W11^T, SW19^T, and YR1^T were 4,181,720 bp, 4,740,677 bp, and 4,228,226 bp, respectively, with DNA G+C contents of 70.5%, 64.2%, and 69.7%, respectively. Average nucleotide identity and digital DNA-DNA hybridization values of W11^T, SW19^T, and YR1^T with their respective reference species were <79.6% and <23.6%, respectively. The predominant cellular fatty acids detected in strain W11^T were anteiso-C_15:0, iso-C_16:0, and anteiso-C_17:0. In strain SW19^T, they were summed feature 9 (C_16:0 10-methyl and/or iso-C_17:1ω 9c), anteiso-C_17:0, and anteiso-C_15:0. Strain YR1^T exhibited C_18:1ω 9c, C_18:0 10-methyl, TBSA, and anteiso-C_15:0 as its major cellular fatty acids. Overall, the polyphasic taxonomic comparisons indicated that strains W11^T, SW19^T, and YR1^T represent novel species within the genera Agromyces, Rathayibacter, and Nocardioides, respectively. Accordingly, we propose the names Agromyces silvae sp. nov., with the type strain W11^T (=KCTC 49818^T =NBRC 115999^T), Rathayibacter soli sp. nov., with the type strain SW19^T (=KCTC 49860^T =NBRC 116108^T), and Nocardioides terrisoli sp. nov., with the type strain YR1^T (=KCTC 49863^T =NBRC 116165^T).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.461-475
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• 2006

In this paper, it is described about the tri-band mobile antenna system design to provide broadband multimedia and direct broadcasting services using goo-stationary Koreasat 3, simultaneously operated in Ka/K/Ku band. The radiating part of the antenna system with a fan beam characteristic in the elevation plane is composed of the quasi-offset dual shaped reflector and the tri-band feeder. The tri-band feeder is also composed of the Ka/K dual band feeder with the protruding dielectric rod, the circular polarizer, the ortho-mode transducer and the circular-polarized Ku band feed array. Especially, the Ka/K dual band circular polarizer was realized firstly using the comb-type structure. For fast satellite-tracking on the movement, the Ku band feed array has the structure of the $2{\times}2$ active phased array which can make electrical beams. And, the circular-polarized characteristic in the feed array was improved by $90^{\circ}$ rotating arrangement of four radiating elements polarized circularly by a $90^{\circ}$ hybrid coupler, respectively. Four beam forming channels to make electrical beams at Ku band are divided into the main beam channel and the tracking beam channel in the output, and noise temperature characteristics of each channel were analyzed on the basis of the contributions of internal sub_units. From the fabricated antenna system, the output power at $P_{1dBc}$ of Ka_Tx channel was measured more than 34.1 dBm and the measured noise figures of K/Ku_Rx channels were less than 2.4 dB and 1.5 dB, respectively, over the operating band. The radiation patterns with co- and cross-polarization in the tri-band were measured using a near-field measurement in the anechoic chamber. Especially, Ku radiation patterns were measured after correcting each initial phase of active channels with partial radiation patterns obtained from the independent excitation of each channel. The antenna gains measured in Ka/K/Ku band of the antenna system were more than 39.6 dBi, 37.5 dBi, 29.6 dBi, respectively. And, the antenna system showed good system performances such as Ka_Tx EIRP more than 43.7 dBW and K/Ku_Rx G/T more than 13.2 dB/K and 7.12 dB/K, respectively.

• Applied Microscopy
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• v.31 no.4
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• pp.333-345
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• 2001

The mature sperms of three species of cephalopods (Octopus minar, Octopus ocellatus, Todarodes pacificus) were observed by electron microscopy. The results obtained are as follows: The sperm lengths of Octopus minor and Octopus ocellatus of octopods are long and they are about $390{\mu}m$ and $125\sim130{\mu}m$, respectively, but the sperm length of Todarodes pacificus is short and about $35{\mu}m$. The sperm of Octopus minor has a helical acrosome and a head bent a little like a banana while Octopus ocellatus of octopod has a twisted acrosome and a long rod-shaped head. A number of horizontal stripes are observed as a periodic structure in their subacrosome cavities and dense plugs are formed in the cavities of their heads. On the other hand, the acrosome of Todarodes pacificus is circular cap-shaped, and its head is long and oval. It is notable that two small cavities were observed in its basal acrosome. Juxtanuclear acrosomal materials of high electron density filled the subacrosomal cavity. In the middle piece of mature sperms of Octopus minor and Octopus ocellatus, the mitochondria form the mitochondrial sleeve, but the numbers of mitochondria differ between the species so that they are $11\sim12$ and $8\sim9$, respectively. Meanwhile, in the middle piece of mature sperms of Todarodes pacificus, the mitochondria are separated from the axoneme, forming a mitochondrial spur in which $10\sim13$ mitochondria and some electron dense materials concentrate. The axoneme of Octopus minor, Octopus ocellatus and Todarodes pacificus are of 9+2 type in common, surrounded by 9 coarse fibres. A number of glycogen were observed only in the axoneme of Todarodes pacificus. The coarse fibres were found as far as the main piece of sperm tail in Octopks minor and Todarodes pacificus, while to the end piece of sperm tail in Octopus ocellatus.