• Asian-Australasian Journal of Animal Sciences
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• v.33 no.12
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• pp.1948-1956
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• 2020

Objective: The purpose of this study was to reveal the metabolic shift in the fungus cocultured with the methanogen (Methanobrevibacter thaueri). Methods: Gas chromatography-mass spectrometry was used to investigate the metabolites in anaerobic fungal (Pecoramyces sp. F1) cells and the supernatant. Results: A total of 104 and 102 metabolites were detected in the fungal cells and the supernatant, respectively. The partial least squares-discriminant analysis showed that the metabolite profiles in both the fungal cell and the supernatant were distinctly shifted when co-cultured with methanogen. Statistically, 16 and 30 metabolites were significantly (p<0.05) affected in the fungal cell and the supernatant, respectively by the co-cultured methanogen. Metabolic pathway analysis showed that co-culturing with methanogen reduced the production of lactate from pyruvate in the cytosol and increased metabolism in the hydrogenosomes of the anaerobic fungus. Citrate was accumulated in the cytosol of the fungus co-cultured with the methanogen. Conclusion: The co-culture of the anaerobic fungus and the methanogen is a good model for studying the microbial interaction between H₂-producing and H₂-utilizing microorganisms. However, metabolism in hydrogenosome needs to be further studied to gain better insight in the hydrogen transfer among microorganisms.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.812-818
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• 2001

Alginate and alginate-derived oligomannuronate enhanced penicillin production in shake flask and fermentor cultures of Penicillium chrysogenum Wis 54-1255 (containing a single copy of the penicillin gene cluster) and in the high producter strain P. chrysogenum AS-P-99 (containing multiple copies of the penicillin gene cluster). Alginate was not used as a single carbon source by P. chryogenum. The stimulatory effect on penicillin production was observed in a defined medium and, to a lower extent, in a complex production medium containing corn steep liquor. Alginate-supplemented cells showed higher transcript levels of the three penicillin biosynthetic genes, pcbAB, pcbC, and penDE, than cells grown in the absence of alginate. The promoters of the pcbAB, pcbC, and penDE genes were coupled to the reporter lacZ gene and introduced as monocopy constructions in P. chrysogenum Wis 54-1225 npe10 by targeted integration in the pyrG locus; the reporter ${\beta}$-galactosidase activity expressed from the three promoters was stimulated by alginate added to the culture medium of the transformants. These results indicate that the stimulation of penicillin production by alginate was derived from an increase in the transcriptional activity of the penicillin biosynthesis genes. The induction by alginate of the transcription of the three penicillin biosynthetic genes is good example of the coordinated induction of secondary metabolism genes by elicitors of plant (or microbial) origin.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.845-852
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• 2001

A microorganism producing fibrinolytic enzyme was isolated from Korean traditional soybean paste and identified as Bacillus sp. KDO-13. The fibrinolytic enzyme was purified to homogeneity by ammonium sulfate fractionation, ion-exchange chromatography on DEAE-celluose, and gel chromatography on Sephadex G-100 of the culture supernatant of Bacillus sp. KDO-13. The molecular weight of the purified enzyme was estimated to be 44,000 by SDS-PAGE. The optimum pH and temperature for the enzyme activity were pH 8.0 and $50{\circ}C$, respectively. The enzyme activity was relatively stable at pH 7.0-9.0 and temperature below $50{\circ}C$. the activity of the enzyme was inhibited by $AI^{3+}$ and $Hg^{2+}$, but activated by $Co^{2+}$\;and\;Ni^{2+}. In addition, the enzyme activity was potently inhibited by EDTA and 0-phenanthroline. The purified enzyme could completely hydrolyze a fibrin substrate within 6 h in vitro, and had a low $K_m$ value for fibrin hydrolysis. It was concluded that the purified enzyme was a metalloprotease with relatively high specificity for fibrinolysis, and thus, could be applied as an effective thrombolytic agent.

• KSBB Journal
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• v.24 no.5
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• pp.453-457
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• 2009

Contamination of marine environment with hazardous and toxic chemicals is more common these days. Bioremediation is the application of microorganism or microbial processes to degrade environmental contaminant. Because of low water solubility and volatility of diesel, bioremediation is more efficient than physical and chemical methods. The objective of this study is biodegradation of diesel in sea water by using Rhodococcus fascians which is isolated petroleum-contaminated soil. R. fascians was cultured on sea water containing diesel to determine the diesel degradability. Changes in biodegradability of diesel with various inoculum sizes, diesel concentrations, initial pH, and culture temperature were analyzed by TPH analysis using gas chromatography. The inoculum size 2% was effective for biodegrdation of diesel in sea water by R. fascians. When diesel concentration was 5%, the growth of cell was inhibited by the toxicity of diesel. The optimal temperature and initial pH for degradation of diesel in sea water were $27^{\circ}C$ and pH 8.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.547-559
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• 2007

Bacillus thuringiensis (Bt) was first described by Berliner [10] when he isolated a Bacillus species from the Mediterranean flour moth, Anagasta kuehniella, and named it after the province Thuringia in Germany where the infected moth was found. Although this was the first description under the name B. thuringiensis, it was not the first isolation. In 1901, a Japanese biologist, Ishiwata Shigetane, discovered a previously undescribed bacterium as the causative agent of a disease afflicting silkworms. Bt was originally considered a risk for silkworm rearing but it has become the heart of microbial insect control. The earliest commercial production began in France in 1938, under the name Sporeine [72]. A resurgence of interest in Bt has been attributed to Edward Steinhaus [105], who obtained a culture in 1942 and attracted attention to the potential of Bt through his subsequent studies. In 1956, T. Angus [3] demonstrated that the crystalline protein inclusions formed in the course of sporulation were responsible for the insecticidal action of Bt. By the early 1980's, Gonzalez et al. [48] revealed that the genes coding for crystal proteins were localized on transmissible plasmids, using a plasmid curing technique, and Schnepf and Whiteley [103] first cloned and characterized the genes coding for crystal proteins that had toxicity to larvae of the tobacco hornworm, from plasmid DNA of Bt subsp. kurstaki HD-1. This first cloning was followed quickly by the cloning of many other cry genes and eventually led to the development of Bt transgenic plants. In the 1980s, several scientists successively demonstrated that plants can be genetically engineered, and finally, Bt cotton reached the market in 1996 [104].

• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1604-1613
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• 2018

Lactobacillus rhamnosus GG (LGG) is a probiotic commonly used in fermented dairy products. In this study, RNA-sequencing was performed to unravel the effects of acid stress on LGG. The transcriptomic data revealed that the exposure of LGG to acid at pH 4.5 (resembling the final pH of fermented dairy products) for 1 h or 24 h provoked a stringent-type transcriptomic response wherein stress response- and glycolysis-related genes were upregulated, whereas genes involved in gluconeogenesis, amino acid metabolism, and nucleotide metabolism were suppressed. Notably, the pilus-specific adhesion genes, spaC, and spaF were significantly upregulated upon exposure to acid-stress. The transcriptomic results were further confirmed via quantitative polymerase chain reaction analysis. Moreover, acid-stressed LGG demonstrated an enhanced mucin-binding ability in vitro, with 1 log more LGG cells (p < 0.05) bound to a mucin layer in a 96-well culture plate as compared to the control. The enhanced intestinal binding ability of acid-stressed LGG was confirmed in an animal study, wherein significantly more viable LGG cells (${\geq}2log\;CFU/g$) were observed in the ileum, caecum, and colon of acid-stressed LGG-treated mice as compared with a non-acid-stressed LGG-treated control group. To our knowledge, this is the first report showing that acid stress enhanced the intestine-binding ability of LGG through the induction of pili-related genes.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.230-232
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• 2005

The formation of insoluble aggregation of the recombinant kringle fragment of human apolipoprotein(a), rhLK8, in endoplasmic reticulum was identified as the rate-limiting step in the rhLK8 secretion in Saccharomyces cerevisiae. To analyze the protein secretion pathway, some of yeast genes closely related to protein secretion was rationally selected and their oligomer DNA were arrayed on the chip. The expression profiling of these genes during the induction of rhLK8 in fermentor fed-batch cultures revealed that several foldases including pdi1 gene were up-regulated in the early induction phase, whereas protein transport-related genes were up-regulated in the late induction phase. The coexpression of pdi1 gene increased rhLK8-folding capacity. Hence, the secretion efficiency of rhLK8 in the strain overexpressing pdi1 gene increased by 2-fold comparing in its parental strain. The oligomer DNA chip arrayed with minimum number of the genes selected in this study could be generally applicable to the monitoring system for the heterologous protein secretion and expression in Saccharomyces cerevisiae. With the optimization of fed-batch culture conditions and the alteration of genetic background of host, we obtained extracellular rhLK8 at higher yields than with Pichia pastoris systems, which was a 25-fold increased secretion level of rhLK8 compared to the secretion level at the initiation of this study.

• The Journal of Korean Society of Virology
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• v.30 no.3
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• pp.179-187
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• 2000

The etiology of rheumatic arthritis (RA) is associated with a number of genetic and environmental factors, but is not definitively elucidated. Recently, more attention has been paid to the possibility of microbial etiology in the pathogenesis of RA, because many different infectious agents have been reported to precede the onset or exacerbation of RA. Adenovirus (ADV) may be one cause of persistent or recurrent inflammatory arthritis. Varicella zoster virus (VZV) arthritis is detected frequently in RA patients treated with low dose methotrexate. The demonstration of simultaneous presence of both viral agents of specific viral nucleic acid in synovial fluids from synovitis patients would provide more direct evidence for arthritis etiological relationship, but there are no confirmed results. Therefore, we studied the ability of adenovirus and VZV to establish coinfection and persistent infection in synovial fluid from synovitis patients. The presence of viral agents in the synovial fluid demonstrated by isolation of cell culture, enzyme immunoassay and nested-PCR. The synovial fluids were also investgated for the presence of viral nucleic acid by nested-PCR using specific primer. ADV produced 220 bp and VZV produced 447 bp by each nested-PCR with specific primers. We detected 4/6 cases (66.7%) with persistent infection of ADV and 5/6 cases (83.3%) of VZV with 13 synovial fluids (between 7 to 52 day intervals) from synovitis patients by monoclonal ErA and nested-PCR. 21/28 cases (75%) with coinfection of adenovirus and VZV with synovial fluids from synovitis patients by nested-PCR. ADV and VZV coinfection and persistent infection of synovial fluids may provide a chronic antigenic stimuli to the immune system therefore provoking a continuing inflammatory response and caused the possibility of synovitis and arthritis.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1188-1192
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• 2003

Chitinase producing bacteria, Arthrobacter nicotianae CH4 and A. nicotianae CH13, were isolated from small crabs by an enrichment culture using chitin as the sole carbon source. Crude chitinases from the two isolated strains, A. nicotianae CH4 and A. nicotianae CH13, were stable in the pH range of $3.0{\sim}9.0$ and in the temperature range of $20{\sim}60^{\circ}C$. The reducing sugar $(GlcNAc)_1$, or $(GlcNAc)_4$, corresponding to over 98% of the enzyme reaction products, was obtained. The production of functional $(GlcNAc)_1$ and $(GlcNAc)_4$ from A. nicotianae CH13 and A. nicotianae CH4, respectively, from the chitinases was useful. The chitinase system of A. nicotianae CH13 was supposed to be endo- and exo-chitinase, and N-acetylglucosaminidase.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.254-257
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• 2012

The different microbial species were isolated from soy bean paste samples. A yeast strain NASS-2 was effective to decrease odor activity on pig excreata was identified as Pichia farinosa based on nucleotide sequences of 18S ribosomal DNA and Internal transcribed space (ITS). The extracellular fraction of P. farinosa NASS-2 was effective to decrease odor activity of pig excrements. Optimal medium component for decreasing order activity on odor material composed of soluble starch 2.0% (w/v) and yeast extract 0.8% (v/v). The decrease of odor material was maximum at $28^{\circ}C$ for 72 hours with pH 5.5. When the P. farinosa NASS-2 culture broth was treated to pig excrements, the removal efficiency was an average concentration with 1.38 ppm of ammonia gas.