• Food Science of Animal Resources
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• v.22 no.4
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• pp.289-293
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• 2002

This study was conducted to investigate changes of pH, meat color, cooking loss, shear force and sensory evaluation on Hanwoo meat fed with supplemental fig fermentation(SFF) during storage period. A total of 10 Hanwoo bulls were subjected to one of two treatment diets (control and 10% SFF) from live weight of 400kg far 6 months. After slaughter, longissimus muscles were removed, zipper-wrapped and stored at 4$\^{C}$ for 21 days. The pH, meat color, cooking loss, shear force and sensory evaluation of the samples were measured at 1, 3, 9, 15, 21 days of storage. There were no differences in pH, meat objective color(Hunter L, a and b) and cooking loss (%) of longissimus muscles between control and SFF treatment during storage. Shear force values of longissimus muscle from SFF treatment showed lower level in 1, 3 and 9 days and tended to decrease during storage. No differences in odor and appearance of sensory evaluation were observed between control and SFF treatment during storage. The taste induced by SFF was increased(f<0.05) at 1, 3 and 9 days of storage. These results indicate that the SFF may improve meat quality of Hanwoo during storage.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.240-247
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• 2010

Pseudomonas aeruginosa is a Gram (-) opportunistic human pathogen causing a wide variety of infections on lung, urinary tract, eyes, and burn wound sites and quorum sensing (QS), a cell density-sensing mechanism plays an essential role in Pseudomonas pathogenesis. In order to investigate the importance of QS in the Pseudomonas infections of Korean patients, we isolated 189 clinical strains of P. aeruginosa from the patients in Pusan Paik Hospital, Busan, South Korea. The QS signal production of these clinical isolates was measured by signal diffusion assay on solid media using reporter strains. While most clinical strains (79.4%) produced the QS signals as similar level as a wild type strain, PAO1 did, where LasR, the initial QS signal sensor-regulator was fully activated, a minority of them (4.2%) produced much less QS signals at the level to which LasR failed to respond. Similarly, while 72.5% of the clinical isolates produced QS signals enough to activate QscR, an another QS signal sensor-regulator, some few of them (9%) produced the QS signals at much lower level where QscR was not activated. For further analysis, we selected 74 clinical strains that were obtained from the patients under suspicion of Pseudomonas infection and investigated the total protease activity that is considered important for virulence. Interestingly, significant portion of them showed very low protease activity (44.6%) or no detectable protease activity (12.2%). When the biofilm-forming ability that is considered very important in chronic infection was examined, most isolates showed lower biofilm-forming activity than PAO1. Similarly, significant portion of clinical isolates showed reduced motility (reduced swarming activity in 51.4% and reduced twitching activity in 41.9%), or non-detectable motility (swarming-negative in 28.4% and twitching-negative in 28.4%). Our result showed that the clinical isolates that produced QS signals at the similar level to wild type could have significantly reduced activities in the protease production, biofilm formation, and motility, and some clinical isolates had unique patterns of motility, biofilm formation, and protease production that are not correlated to their QS activity.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.233-239
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• 2010

Four genes (yqfR, yfmL, ydbR, deaD) were identified as putative DEAD-box RNA helicase genes in the genomic sequence of Bacillus subtilis by homology search. To understand the function of these genes, each of the genes was deleted and the constructed strains were tested for their growth charateristics at different temperatures. The growth rate of ydbR deletion mutant ($T_d$=53 min) was a little bit reduced at $37^{\circ}C$ as compared to that of wild type strain (CU1065). But the growth rate of other three (yqfR, yfmL, deaD) deletion mutants ($T_d$=30-40 min) is nearly equal to the growth rate of wild type ($T_d$=32 min). On the other hands, the growth rate of deletion mutants were reduced at $22^{\circ}C$ in order of yqfR ($T_d$=151 min), yfmL ($T_d$=214 min), ydbR ($T_d$=343 min), which showed cold-sensitive phenotype. The deletion mutant of deaD ($T_d$=109 min) grew equally as compared to the growth rate ($T_d$=102 min) of the wild type at $22^{\circ}C$ and did not show cold-sensitive growth. Double, triple and quadruple deletion mutants of these genes were constructed, and growth rate of these mutants were measured at various temperature conditions ($22^{\circ}C$, $37^{\circ}C$, $42^{\circ}C$) using LB broth. Multiple deletion mutations showed more severe cold-sensitive growth than single deletion mutations, and double deletion of ydbR and yfmL ($T_d$=984 min) showed most cold-sensitive growth than any other double mutants. Such a cold-sensitive growth of these mutations is quite similar to the result of csdA or srmB deletion in E. coli and suggested that physiological role of ydbR and yfmL is related with ribosome assembly.

• Journal of Life Science
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• v.24 no.6
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• pp.618-625
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• 2014

Rice flour is used in many food products. However, dough made from rice lacks extensibility and elasticity, making it less suitable than wheat for many food products such as bread and noodles. The high-molecular weight glutenin subunits (HMW-GS) of wheat play a crucial role in determining the processing properties of the wheat grain. This paper describes the development of marker-free transgenic rice plants expressing a wheat Glu-Dy10 gene encoding the HMG-GS from the Korean wheat cultivar 'Jokyeong' using Agrobacterium-mediated co-transformation. Two expression cassettes, consisting of separate DNA fragments containing Glu-1Dy10 and hygromycin phosphotransferase II (HPTII) resistance genes, were introduced separately into Agrobacterium tumefaciens EHA105 for co-infection. Each EHA105 strain harboring Glu-1Dy10 or HPTII was infected into rice calli at a 3: 1 ratio of Glu-1Bx7 and HPTII. Among 290 hygromycin-resistant $T_0$ plants, we obtained 29 transgenic lines with both the Glu-1Dy10 and HPTII genes inserted into the rice genome. We reconfirmed the integration of the Glu-1Dy10 gene into the rice genome by Southern blot analysis. Transcripts and proteins of the Glu-1Dy10 in transgenic rice seeds were examined by semi-quantitative RT-PCR and Western blot analysis. The marker-free plants containing only the Glu-1Dy10 gene were successfully screened in the $T_1$ generation.

• Journal of Life Science
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• v.29 no.5
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• pp.545-554
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• 2019

The phytochemical compounds of Pueraria, a medicinally important leguminous plant, include various isoflavones that have weak estrogenic activity and a potential role in preventing chronic disease, cancer, osteoporosis, and postmenopausal syndrome. However, the major isoflavones are derivatives of puerarin and occur mainly as unabsorbable and biologically inactive glycosides. The bioavailability of the glucosides can be increased by hydrolysis of the sugar moiety using ${\beta}$-glucosidase. In this study, we investigated the antioxidant effects of a Pueraria extract after fermentation by Lactobacillus rhamnosus BHN-LAB 76. The L. rhamnosus BHN-LAB 76 strain was inoculated into Pueraria powder and fermented at $37^{\circ}C$ for 72 hr. The total polyphenol content of the Pueraria extract increased by about 134% and the total flavonoid content increased around 110% after fermentation with L. rhamnosus BHN-LAB 76 when compared to a non-fermented Pueraria extract. Superoxide dismutase-like activities, DPPH radical scavenging, and ABTS radical scavenging increased by approximately 213%, 190%, and 107%, respectively, in the fermented Pueraria extract compared to the non-fermented Pueraria extract. Fermentation of Pueraria extracts with L. rhamnosus BHN-LAB 76 is therefore possible and can effectively increase the antioxidant effects. These results can be applied to the development of improved foods and cosmetic materials.

• Tuberculosis and Respiratory Diseases
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• v.65 no.3
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• pp.177-182
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• 2008

Background: Isoniazid (INH, H) is a key drug of the standard first-line regimen for the treatment of tuberculosis (TB), yet some reports have suggested that treatment efficacy was maintained even though INH was omitted from the treatment regimen. Methods: One hundred forty C57BL/6 mice were infected with the H37Rv strain of M. tuberculosis with using a Glas-Col aerosol generation device, and this resulted in depositing about 100 bacilli in the lung. Four weeks after infection, anti-TB treatment was initiated with varying regimens for 4-8 weeks; Group 1: no treatment (control), Group 2 (4HREZ): 4 weeks of INH, rifampicin (R), pyrazinamide (Z) and ethambutol (E), Group 3: 1HREZ/3REZ, Group 4: 4REZ, Group 5: 4HREZ/4HRE, Group 6: 1HREZ/3REZ/4RE, and Group 7: 4REZ/4RE. The lungs and spleens were harvested at several time points until 28 weeks after infection, and the colony-forming unit (CFU) counts were determined. Results: The CFU counts increased steadily after infection in the control group. In the 4-week treatment groups (Group 2-4), even though the culture was negative at treatment completion, the bacilli grew again at the 12-week and 20-week time points after completion of treatment. In the 8-week treatment groups (Groups 5-7), the bacilli did not grow in the lung at 4 weeks after treatment initiation and thereafter. In the spleens of Group 7 in which INH was omitted from the treatment regimen, the culture was negative at 4-weeks after treatment initiation and thereafter. However, in Groups 5 and 6 in which INH was taken continuously or intermittently, the bacilli grew in the spleen at some time points after completion of treatment. Conclusion: TThe exclusion of INH from the standard first-line regimen did not affect the treatment outcome in a murine model of TB in the early stage of disease. Further studies using a murine model of chronic TB are necessary to clarify the role of INH in the standard first-line regimen for treating TB.