• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2012년도 학술발표논문집
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• pp.139-144
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• 2012

• Journal of the Korean Wood Science and Technology
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• 제33권2호통권130호
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• pp.24-28
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• 2005

Monte Carlo simulation was performed on theoretical models of plywood warp for southern yellow pine plywood originating from the United States. The objective of the investigation was to determine which plywood layers was more warp sensitive to veneers that were manufactured to an undesired thickness. This study found that for a balanced panel (a panel of equal target thickness for each of five layers) manufactured veneers of undesired thickness would experience minimal warp. The veneers of undesired thickness placed in the center of the plywood panel also provided a minimum change of plywood warp properties. The panel warp was very sensitive to surface veneers constructed with undesired thickness. Conversely, this study confirms that monitoring of veneer thickness and proper allocations within the plywood lay-up were critical.

• Journal of Microbiology and Biotechnology
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• 제33권6호
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• pp.831-839
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• 2023

Tylosin is a potent veterinary macrolide antibiotic produced by the fermentation of Streptomyces fradiae; however, it is necessary to modify S. fradiae strains to improve tylosin production. In this study, we established a high-throughput, 24-well plate screening method for identifying S. fradiae strains that produce increased yields of tylosin. Additionally, we constructed mutant libraries of S. fradiae via ultraviolet (UV) irradiation and/or sodium nitrite mutagenesis. A primary screening of the libraries in 24-well plates and UV spectrophotometry identified S. fradiae mutants producing increased yields of tylosin. Mutants with tylosin yield 10% higher than the wild-type strain were inoculated into shake flasks, and the tylosin concentrations produced were determined by high-performance liquid chromatography (HPLC). Joint (UV irradiation and sodium nitrite) mutagenesis resulted in higher yields of mutants with enhanced tylosin production. Finally, 10 mutants showing higher tylosin yield were re-screened in shake flasks. The yield of tylosin A by strains UN-C183 (6767.64 ± 82.43 ㎍/ml) and UN-C137 (6889.72 ± 70.25 ㎍/ml) was significantly higher than that of the wild-type strain (6617.99 ± 22.67 ㎍/ml). These mutant strains will form the basis for further strain breeding in tylosin production.

• 한국동물위생학회지
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• 제30권1호
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• pp.115-123
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• 2007

The therapeutic effect of honeybee venom collected using be venom collector on bovine mastitis was investigated. Mastitic cows from four farms were selected in the Yang-pyeong areas. Chronic mastitic cows were injected with the various concentrations of honey-bee venom per day. There was a significant difference in the reduction rates of somatic cell counts (SCC) according to treatment concentration and method of bee venom. The milk SCC were significantly decreased in all concentrations of bee venom 3 days after treatment. The reduction rates of SCC in treatment of 3, 6, 12 and 24mg honeybee venom were 20, 43, 63.3 and 65.8% respectively. Honeybee venom treatment consisted of two methods, a syringeful and a Bovivet Spenstift. The treatment with Bovivet Spenstift was more effective in the reduction rates of SCC compared with the syringeful. Thirty two out of 53 quarters were cured by Bovivet Spenstift with 12mg bee venom per day for 14 days. The venom cure rates of bovine mastitis by Escherichia coli, Stapylococcus aureus, Gram positive bacteria and Gram negative bacteria were 33.3, 75, 75 and 43.8% respectively. These results suggested that bee venom treatment (by Bovivet Spenstift with 12mg) might be effective for treatment of bovine mastitis.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2011년도 추계학술발표회
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• pp.290-291
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• 2011

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2012년도 심포지엄 및 춘계학술발표회
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• pp.293-294
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• 2012

• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1287-1298
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• 2024

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that is currently difficult to treat effectively. Both Bacillus natto (BN) and ginseng-soluble dietary fiber (GSDF) are anti-inflammatory and helps sustain the intestinal barrier. In this study, the protective effects and mechanism of the combination of B. natto JLCC513 and ginseng-soluble dietary fiber (BG) in DSS-induced UC mice were investigated. Intervention with BG worked better than taking BN or GSDF separately, as evidenced by improved disease activity index, colon length, and colon injury and significantly reduced the levels of oxidative and inflammatory factors (LPS, ILs, and TNF-α) in UC mice. Further mechanistic study revealed that BG protected the intestinal barrier integrity by maintaining the tight junction proteins (Occludin and Claudin1) and inhibited the LPS/TLR4/NF-κB pathway in UC mice. In addition, BG increased the abundance of beneficial bacteria such as Bacteroides and Turicibacter and reduced the abundance of harmful bacteria such as Allobaculum in the gut microbiota of UC mice. BG also significantly upregulated genes related to linoleic acid metabolism in the gut microbiota. These BG-induced changes in the gut microbiota of mice with UC were significantly correlated with changes in pathological indices. In conclusion, this study demonstrated that BG exerts protective effect against UC by regulating the LPS/TLR4/NF-κB pathway and the structure and metabolic function of gut microbiota. Thus, BG can be potentially used in intestinal health foods to treat UC.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.616-625
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• 2005

It is likely that maltose could provide a good substrate for the bacteria in the intestine, when the pathogenic bacteria invade and colonize in human gut. For better understanding of this organism's maltose metabolism, a mutant that was not able to grow with maltose as a sole carbon source was screened from a library of mutants constructed by a random transposon mutagenesis. By a transposon-tagging method, malPQ genes encoding a maltodextrin phosphorylase and a 4-${\alpha}$-glucanotransferase, were identified and cloned from Vibrio vulnificus. The deduced amino acid sequences of malPQ from V. vulnificus were 48 to $91\%$ similar to those of MalP and MalQ reported from other Enterobacteriaceae. Functions of malPQ genes were assessed by the construction of mutants whose malPQ genes were inactivated by allelic exchanges. When maltose was used as the sole carbon source, neither malP nor malQ mutant was able to grow to a substantial level, revealing that the MalP and MalQ are the only enzymes for metabolic utilization of maltose. The malQ mutant exhibited decreased adherence toward intestinal epithelial cells in vitro, but there was no difference in the $LD_{50}s$ of the wild-type and the malQ mutant in mice. Therefore, it appears that MalQ is less important in the pathogenesis of V. vulnificus than would have been predicted by considering maltose as a most common sugar in the intestine, but not completely dispensable for virulence in mice.

• Food Science and Biotechnology
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• 제14권6호
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• pp.860-865
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• 2005

A gene for a putative glucoamylase, stg, of a hyperthermophilic archae on Sulfolobus tokodaii was cloned and expressed in Escherichia coli. The recombinant glucoamylase (STGA) had an optimal temperature of $80^{\circ}C$ and was extremely thermostable with a D-value of 17 hr. The pH optimum of the enzyme was 4.5. Being different from fungal glucoamylases, STGA hydrolyzed maltotriose (G3) most efficiently. Gel permeation chromatography and sedimentation equilibrium analytical ultracentrifugation analysis showed that the enzyme existed as a dimer. STGA was stable enough to hydrolyze liquefied com starch to glucose in 4 hr at $90^{\circ}C$ with a yield of95%. Comparison of the $k_{cat}$ values for the hydrolysis and the reverse reaction at $75^{\circ}C$ and $90^{\circ}C$ indicated that glucose production by STGA was more efficient at $90^{\circ}C$ than $75^{\circ}C$. Therefore, STGA showed great potential for application to the industrial glucose production process due to its high thermostability.

• Food Science and Biotechnology
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• 제15권5호
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• pp.817-819
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• 2006

8-Quinolinol and other quinolinol derivatives were evaluated with regard to their growth-inhibitory effects against intestinal bacteria, using the paper disk-agar diffusion method. The observed growth responses varied according to the chemicals and dosages used, as well as the bacterial species tested. 8-Quinolinol showed a significant inhibitory effect against Clostridium difficile, C. perfringens, and Escherichia coli, at 5, 2, 1, and 0.5 mg/disk, and also exhibited a very strong inhibitory effect at 0.25 mg/disk. At low concentrations, 8-quinolinol had strong inhibitory effects against C. perfringens at 0.1 and 0.05 mg/disk; 8-quinolinol also manifested a moderate inhibitory effect against C. perfringens at 0.025 mg/disk. Furthermore, 8-quinolinol revealed moderate and weak growth inhibition against C. difficile and E. coli at concentrations of 0.1 and 0.05 mg/disk, respectively, but 2-quinolinol, 4-quinolinol, and 6-quinolinol evidenced no growth inhibition against B. bifidum, B. longum, C. difficile, C. perfringens, E. coli, or L. casei. The inhibitory effects of 8-quinolinol against C. difficile, C. perfringens, and E. coli lead to its consideration as a possible therapeutic modality for the treatment of diseases associated with harmful intestinal bacteria.