• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.383-383
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• 2005

• Food Science and Biotechnology
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• 제14권1호
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• pp.147-151
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• 2005

Purified compound with intestinal immune system-modulating properties, GWE-2c, was isolated from methanol extract of Gelidium amansii by sequential procedures with silica gel column, LH-20 Sephadex gel column, and thin-layer chromatographies. In the presence of GWE-2c, strong immunoactivity in Peyers patch cell-mediated bone marrow cells was observed in vitro. In vivo intestinal immune-modulating activity was also enhanced by crude phenolic compound (GWE) of G. amansii in a dose-dependent manner. Investigation of production of several cytokines in Peyer's patch cells upon stimulation with GWE in vivo revealed the levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-6 increased. Results suggest that the phenolic compound from G. amansii represents immunopotentiator and biological response modifier at in vitro and in vivo levels.

• Journal of Microbiology and Biotechnology
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• 제32권2호
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• pp.195-204
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• 2022

Chinese chive (Allium tuberosum Rottler) has potential risks associated with pathogenic bacterial contamination as it is usually consumed raw. In this study, we investigated the microbiota of Chinese chives purchased from traditional markets and grocery stores in March (Spring) and June (Summer) 2017. Differences in bacterial diversity were observed, and the microbial composition varied across sampling times and sites. In June, potential pathogenic genera, such as Escherichia, Enterobacter, and Pantoea, accounted for a high proportion of the microbiota in samples purchased from the traditional market. A large number of pathogenic bacteria (Acinetobacter lwoffii, Bacillus cereus, Klebsiella pneumoniae, and Serratia marcescens) were detected in the June samples at a relatively high rate. In addition, the influence of the washing treatment on Chinese chive microbiota was analyzed. After storage at 26℃, the washing treatment accelerated the growth of enterohemorrhagic Escherichia coli (EHEC) because it caused dynamic shifts in Chinese chive indigenous microbiota. These results expand our knowledge of the microbiota in Chinese chives and provide data for the prediction and prevention of food-borne illnesses.

• 한국수산과학회지
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• 제53권6호
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• pp.842-850
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• 2020

The objective of this study was to evaluate the effect of the depuration process (artificial seawater sterilization using UV light) for extending the shelf life of raw oyster Crassostrea gigas and maintaining food quality. To confirm the effects of depuration, microbiological (viable cell count) and several physiochemical analyses (pH and glycogen levels in shucked oyster and pH, soluble protein, and turbidity in filling water) were carried out during the storage of raw oysters. The results showed that depuration could effectively extend the shelf life (2-3 days) of raw oysters with minimal change in food quality, including pH and glycogen content. Thus, the depuration process proposed in this study could successfully be applied to processing practices for other shellfish to extend their shelf life and contribute to the management of seafood safety issues.

• Journal of Microbiology and Biotechnology
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• 제30권1호
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• pp.44-53
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• 2020

Calcium is an element that performs many important functions in the human body. A study was conducted on the use of a pulsed electric field (PEF) to enrich cells of Lactobacillus rhamnosus B 442 in calcium ions. The highest concentration of calcium ions in bacterial cells (7.30 mg/g d.m.) was obtained at ion concentration of 200 ㎍/ml of medium and with the use of the following PEF parameters: field strength 3.0 kV/cm, exposure time 10 min, pulse width 75 ms and 20 h of culturing after which bacteria were treated with the field. Cell biomass varied in the range from 0.09 g/g d.m. to 0.252 g/g d.m., and the total number of bacteria ranged from 10¹⁰ CFU/ml to 10¹² CFU/ml. Microscope photographs prove that calcium ions were situated within the cells of the bacteria, and electroporation contributed to an increase in the effectiveness of the ion bioaccumulation process. Samples containing calcium and subjected to electroporation displayed intensive fluorescence. The significance of this research was the possibility of using probiotic bacteria enriched with calcium ions for the production of functional food in subsequent studies.

• Food Science and Biotechnology
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• 제15권6호
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• pp.967-974
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• 2006

Cyclomaltodextrinases (CDases), maitogenic amylases, and neopullulanases share highly conserved primary structures and similar characteristics, and are thus classified into the same family. BLAST search has showed that a variety of bacterial strains harbor putative CDase family genes with several well-conserved motif amino acid sequences. In this study, four degenerate polymerase chain reaction (PCR) primer sets were designed for the detection of CDase genes, on the basis of their highly conserved amino acid blocks (WYQIFP, DGWRLD, LGSHDT, and KCMVW). The PCR detection conditions were optimized and the detection specificity of each for the primer sets was tested against the genomic DNAs isolated from 23 different Bacillus-associated species. Consequently, all tested primer sets evidenced successful amplification of specific PCR products in length, which share 55-98% amino acid sequence identity with known and putative CDases. The primers developed herein, therefore, can be applied for the easy and efficient detection and isolation of CDase family genes for the modification of functional food carbohydrates.

• Food Science and Biotechnology
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• 제14권4호
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• pp.441-445
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• 2005

Pinitol and chiro-inositol exert insulin-like effect by mediating post-receptor signaling pathway. Total chiro-inositol concentrations, including pinitol, chiro-inositol, and their derivatives, were determined in 115 natural and food materials to identify economical sources for mass production of pinitol. Carob pod, Bougainvillea, soy whey, and soybean oligosaccharides were rich sources of chiro-inositol. Pinitol was isolated from soy whey and carob pod, considered as economically viable sources, by chromatographic separation using activated carbon. Soy and carob pinitols had same chemical structure as that of reference pinitol based on HPLC and NMR results. Oral administration of soy pinitol and carob pinitol (10 mg/kg) significantly decreased blood glucose at 2-6 hr in streptozotocin-induced diabetic rats. These results suggest pinitol isolated from soy whey and carob pod could be beneficial in controlling blood glucose in animal model of diabetes mellitus.

• Preventive Nutrition and Food Science
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• 제14권1호
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• pp.29-36
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• 2009

To compare antioxidative and antiaging effects between yellow soybean (YS) and Chungkukjang (CK) in vivo system, male Sprague-Dawley rats (n=24) were fed the diets containing YS and CK for 8 weeks, respectively. The YS and CK groups showed the preventive effects on lipid and protein oxidations in liver and plasma. Hepatic SOD and GSH-peroxidase activities were significantly inhibited in CK group. Superoxide anion radicals in cytosol significantly lowered in YS and CK groups compared with control group. In addition, dietary YS and CK effectively inhibited formation of the lipofuscin, the indicator of aging in heart and eye, especially the CK group had a stronger preventive activity in eye. The results of this study showed that YS and CK diet effectively suppressed the superoxide anion radical formation and tissue oxidation.

• Food Science and Biotechnology
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• 제15권1호
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• pp.148-151
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• 2006

Multiplex PCR was performed to simultaneously detect eight different events of genetically modified (GM) maize. Specific primers were constructed from GA21, T25, TC1507, Mon810, Mon863, Event176, Bt11, and NK603 events of GM maize. Using this PCR method, specific GM maize was monitored in commercialized foods and feed.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1521-1526
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• 2007

A maltogenic amylase gene from Lactobacillus gasseri ATCC33323 (LGMA) was expressed in Lactococcus lactis MG1363 using the P170 expression system. The successful production of recombinant LGMA (rLGMA) was confirmed by the catalytic activity of the enzyme in liquid and solid media. The N-terminal amino acid sequencing analysis of the rLGMA showed that it was Met-Gln-Leu-Ala-Ala-Leu-, which was the same as that of genuine protein, meaning the signal peptide was efficiently cleaved during secretion to the extracellular milieu. The optimal reaction temperature and pH of rLGMA ($55^{\circ}C$ and pH 5, respectively) and enzymatic hydrolysis patterns on various substrates (${\beta}$-cyclodextrin, starch, and pullulan) supported that rLGMA was not only efficiently secreted from the Lactococcus lactis MG1363 but was also functionally active. Finally, the branched maltooligosaccharides were effectively produced from liquefied com starch, by using rLGMA secreted from Lactococcus lactis, with a yield of 53.1%.