• The Plant Pathology Journal
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• v.34 no.3
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• pp.250-255
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• 2018

Pine wilt disease, caused by the nematode Bursaphelenchus xylophilus, is one of the most devastating conifer diseases decimating several species of pine trees on a global scale. Here, we report the draft genome of Raoultella ornithinolytica MG, which is isolated from mountain-cultivated ginseng plant as an bacterial endophyte and shows nematicidal activity against B. xylophilus. Our analysis of R. ornithinolytica MG genome showed that it possesses many genes encoding potential nematicidal factors in addition to some secondary metabolite biosynthetic gene clusters that may contribute to the observed nematicidal activity of the strain. Furthermore, the genome was lacking key components of avermectin gene cluster, suggesting that nematicidal activity of the bacterium is not likely due to the famous anthelmintic agent of wide-spread use, avermectin. This genomic information of R. ornithinolytica will provide basis for identification and engineering of genes and their products toward control of pine wilt disease.

• Korean Journal of Environmental Biology
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• v.38 no.2
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• pp.289-298
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• 2020

As part of the research program "2018 Rapid screening and identification of freshwater microorganisms using MALDI-TOF/MS library" freshwater samples were collected from a branch of the Nakdong River. Almost 300 antibiotic-resistant bacterial strains were isolated from freshwater samples and subsequently identified by 16S rRNA gene sequencing. Seventeen strains among the isolates shared high 16S rRNA gene sequence similarity (>99.0%) with known species that were not previously recorded in Korea, and each of the isolates also formed a robust phylogenetic clade with the closest species. These species were phylogenetically diverse, belonging to four phyla, seven classes, 10 orders, and 13 genera. At the genus and class level, the previously unrecorded species belonged to Rhodovarius, Xanthobacter, and Shinella of the class Alphaproteobacteria; Ottowia, Simplicispira, and Zoogloea of Betaproteobacteria; Pseudomonas, Acinetobacter, and Shewanella of Gammaproteobacteria; Arcobacter of Epsilonproteobacteria; Sphingobacterium of Sphingobacteriia; Trichococcus of Bacilli; and Leucobacter of Actinobacteria. The previously unrecorded species were further characterized by examining their gram-staining, colony and cell morphology, biochemical properties, and phylogenetic position.

• Journal of Veterinary Clinics
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• v.34 no.3
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• pp.161-164
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• 2017

Bovine respiratory disease (BRD) is one of the most important diseases in calves. It causes a huge economic loss in farms. BRD in calves is concentrated during winter because of the cold weather and lack of ventilation. However, BRD during summer in calves has continuously been a problem in farms. But there is no study about pathogens of summer pneumonia in calves and antimicrobial susceptibility in Korea. Therefore, aims of this study were to identify the pathogens and their antimicrobial susceptibility in calves with summer pneumonia. One hundred and one calves (2 weeks to 5 months after birth) with clinical sign of BRD from 5 farms were selected. After sampling by deep nasal swab, bacterial isolation and identification was conducted. Also, antimicrobial susceptibility test was performed. Pasteurella spp (49.4%), Staphylococcus spp (21.5%), Actinomyces spp (12.9%), E coli (10.7%), and Mannheimia haemolytica (5.3%) were isolated. The patterns of isolated pathogens from each farm were various. Also, the susceptibility of bacteria to antibiotics was showed a variety of patterns in each farm.

• Korean Journal Plant Pathology
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• v.14 no.2
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• pp.177-183
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• 1998

A DNA fragment which is involved in tolassin production was cloned to obtain a molecular marker of Pseudomonas tolaasii, a casual agent of bacterial brown blotch disease of oyster mushroom (Pleurotus ostreatus). Tolaasin is a lipodepsipeptide toxin and known as a primary disease determinant of the P. tolaasii. It is responsible for formation of white line in agar when P. tolaasii were cultured against white line reacting organisms (WLROs). White line negative mutants (WL-) were generated by conjugation between rifampicin resistant strain of P. tolaasii and E. coli carrying suicidal plasmid pSUP2021 : : Tn5. The ability of tolaasin production of the WL- mutants was examined by hemolysis test, pathogenicity test, and high pressure liquid chromatography (HPLC) analysis of culture filtrate. All of the WL- mutants were lost the ability of tolaasin production (Tol-). Genomic library of the Tol- mutant was constructed in pLAFR3 and the cosmid clone containing Tn5 was selected. DNA fragment fro franking region of Tn5 was cloned from the plasmid and used as a probe in Southern blot. DNA-DNA hybridization with the probe to total DNA from group of bacteria ecologically similar to P. tolaasii including WLORs, fluorescent Pseudomonads isolated from oyster mushroom, P. agarici, P. gingeri, and some of other species of Psedomonas showed that some of the tested bacteria do not have any hybridized band and others have bands sowing RFLP. The cloned DNA fragment or its nucleotide sequence will be useful in detection and identification of the P. tolaasii.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.2
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• pp.68-75
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• 2019

Chronic recurrent multifocal osteomyelitis (CRMO) is one of the most severe form of chronic non-bacterial osteomyelitis (CNO), which could result in bone and related tissue damage. This autoinflammatory bone disorder (ABD) is very difficult for its clinical diagnosis because of no diagnostic criteria or biomarkers. CRMO in the jaw must be suspected in the differential diagnosis of chronic and recurrent bone pain in the jaw, and a bone biopsy should be considered in chronic and relapsing bone pain with swelling that is unresponsive to treatment. The early diagnosis of CRMO in the jaw will prevent unnecessary and prolonged antibiotic usage or unnecessary surgical intervention. The updated researches for the identification of genetic and molecular alterations in CNO/CRMO should be studied more for its correct pathophysiological causes and proper treatment guidelines. Although our trial consisted of reporting items from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), there are very few articles of randomized controlled trials. This article was summarized based on the author's diverse clinical experiences. This paper reviews the clinical presentation of CNO/CRMO with its own pathogenesis, epidemiology, recent research studies, and general medications. Treatment and monitoring of the jaw are essential for the clear diagnosis and management of CNO/CRMO patients in the field of dentistry and maxillofacial surgery.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.81-88
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• 2022

Acetic acid bacteria (AAB) are versatile organisms involved in the production of variety of fermented foods, such as vinegar and kombucha, and products of biotechnological relevance, such as bacterial cellulose. In the present study, Malatya apricot, a variety with protected designation of origin (PDO), and vinegar samples produced using various fruits were used to isolate AAB. The 19 AAB isolates obtained were typed using (GTG)5 fingerprinting, and the ones selected were identified by sequencing either 16S rDNA alone or in combination with 16S-23S rRNA internal transcribed spacer region or ligA gene. While all apricot isolates (n = 10) were Gluconobacter cerinus, vinegar isolates (n = 9) were composed of Komagataeibacter saccharivorans, Acetobacter syzygii, and possible two new species of AAB, Komagataeibacter sp., and Gluconobacter sp. (GTG)5 fingerprinting showed the presence of several genotypes of G. cerinus in the apricot samples. Screening for some technologically relevant properties, including thermotolerance, ethanol tolerance, and cellulose production capability, showed that all Komagataeibacter and some Gluconobacter isolates could tolerate the temperature of 35℃, and that vinegar isolates could tolerate up to 8% ethanol. One isolate, Komagataeibacter sp. GUS3 produced bacterial cellulose (1 g/l) and has the potential to be used for cellulose production.

• Journal of Microbiology and Biotechnology
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• v.34 no.9
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• pp.1867-1875
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• 2024

Identification of the biochemical metabolic pathway for lignin decomposition and the responsible degradative enzymes is needed for the effective biotechnological valorization of lignin to renewable chemical products. In this study, we investigated the decomposition of kraft lignin by the soil bacterium Pseudomonas kribbensis CHA-19, a strain that can utilize kraft lignin and its main degradation metabolite, vanillic acid, as growth substrates. Gel permeation chromatography revealed that CHA-19 decomposed polymeric lignin and degraded dehydrodivanillin (a representative lignin model compound); however, the degradative enzyme(s) and mechanism were not identified. Quantitative polymerase chain reaction with mRNAs from CHA-19 cells induced in the presence of lignin showed that the putative genes coding for two laccase-like multicopper oxidases (LMCOs) and three dye-decolorizing peroxidases (DyPs) were upregulated by 2.0- to 7.9-fold compared with glucose-induced cells, which indicates possible cooperation with multiple enzymes for lignin decomposition. Computational homology analysis of the protein sequences of LMCOs and DyPs also predicted their roles in lignin decomposition. Based on the above data, CHA-19 appears to initiate oxidative lignin decomposition using multifunctional LMCOs and DyPs, producing smaller metabolites such as vanillic acid, which is further degraded via ortho- and meta-ring cleavage pathways. This study not only helps to better understand the role of bacteria in lignin decomposition and thus in terrestrial ecosystems, but also expands the biocatalytic toolbox with new bacterial cells and their degradative enzymes for lignin valorization.

• Korean Journal of Veterinary Research
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• v.48 no.1
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• pp.89-92
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• 2008

The pirarucu, Arapaima gigas (body weight = 18.3 kg and total length = 102 cm) which had been reared in one of the private commercial aquaria for exhibition was found dead and submitted for diagnostic examination. A pure bacterial culture was isolated from the kidney, which was enlarged, and contained fluids. Result of the bacterial identification yielded Serratia fonticola. This paper describes the first isolation of S. fonticola from pirarucu.

• Journal of Microbiology
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• v.42 no.1
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• pp.9-13
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• 2004

Culture-independent approaches, based on 16S rDNA sequences, are extensively used in modern microbial ecology. Sequencing of the clone library generated from environmental DNA has advantages over fingerprint-based methods, such as denaturing gradient gel electrophoresis, as it provides precise identification and quantification of the phylotypes present in samples. However, to date, no method exists for comparing multiple bacterial community structures using clone library sequences. In this study, an automated method to achieve this has been developed, by applying pair wise alignment, hierarchical clustering and principle component analysis. The method has been demonstrated to be successful in comparing samples from various environments. The program, named CommCluster, was written in JAVA, and is now freely available, at http://chunlab.snu.ac.kr/commcluster/.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.345-348
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• 2002

A rapid spectrophotometric method for detecting the mucinase complex was developed. Bovine submaxillary mucin is cleaved by commercial mucinase between the oligosaccharide chain and the side chain of peptide linkage, thereby liberating the N-acetyl neuraminic acid (NANA). The release of NANA resulted in an increase of absorbance at 280 nm. The susceptibility to NANA by the new method was found to be at least 10-fold more sensitive than the thiobarbituric acid method. Moreover, the quantification of NANA released from mucin by commercial neuraminidase and partially purified Vibrio parahaemolyticus mucinase showed a good linear correlation in proportion to the concentration of the enzyme used. These results demonstrate that the rapid identification of mucin degradation can be determined by a spectrophotometric assay, thereby providing a new, fast, and sensitive method for assaying the bacterial mucinase complex.