• Journal of agriculture & life science
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• v.45 no.5
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• pp.63-71
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• 2011

This study was conducted to determine the effects of increasing the dietary levels of conjugated linoleic acid (CLA) which is produced from bio diesel by-products, on milk yield, milk composition, and blood metabolites of mid-lactating dairy cows. A total of 20 mid-lactating dairy cows ($631{\pm}25.0kg$) were assigned to one of four treatment groups and fed twice daily an equal amount of a basal diet ($NE_L$ 32 Mcal/d, CP 17%) contained 12kg/d of concentrate, 15kg/d of corn silage and 4kg/d of the hay mixture (tall fescue+orchard grass). Conjugated linoleic acid were fed for 2 weeks of adaptation periods and 4 weeks of collection periods at 0 (Control), 50 (T1), 100 (T2) and 150g/d (T3), respectively. By the increases of dietary CLA supplementation, milk yield and 4% fat corrected milk increased, whereas milk fat content decreased (p<0.05). The concentrations of stearic acid and oleic acid decreased with increasing dietary CLA supplementation, while the concentrations of total CLA increased (p<0.05). In conclusion, this study shown that the supplementation of dietary CLA manufactured from bio diesel by-products could improve milk yield and CLA concentrations of milk in mid-lactating dairy cows.

• Journal of Life Science
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• v.19 no.8
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• pp.1081-1087
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• 2009

In this study, the effects of feeding citrus peel on the nutritional composition of chicken meat were investigated. The samples consisted of chicken meats provided with only feed for laying hens without citrus peel (CP-0), and chicken meats fed with 1.0%, 1.5% and 2.0% citrus peel during the starter (initial period feed; 1${\sim}$9th day), the grower (middle period feed; 10${\sim}$24th day), and the finisher (latter period feed; 25${\sim}$36th day), respectively. There was no significant difference between CP-0 and CP-1 regardless of feeding citrus peel in terms of chicken's moisture, protein, fat, ash or caloric content. The cholesterol content was significantly lower in the CP-1 chicken meats than in the CP-0 chicken meats (p<0.05). The K P and Ca contents were significantly higher in the CP-1 chicken meats than in the CP-0 chicken meats (p<0.05), but there were no significant differences between CP-0 and CP-1, regardless of feeding citrus peet in terms of chicken meat's Na and Mg. There were no significant differences between CP-o and CP-1 regardless of feeding citrus peet in terms of chicken meat's vitamin A, xanthophyll, ${\beta}$-carotene, hesperidin or naringin, but vitamins $B_1$ and $B_2$ were significantly higher in the CP-1 chicken meats than in the CP-0 chicken meats (p<0.05). There were no significant differences between CP-0 and CP-1 regardless of feeding citrus peet in terms of chicken meat's amino acid composition - most of free amino acids and fatty acid composition - but L-glutamic acid was significantly higher in the CP-0 chicken meats than in the CP-1 chicken meats, and the DL-${\beta}$-amino isobutyric acid was significantly higher in the CP-1 chicken meats than in the CP-0 chicken meats (p<0.05).

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.457-461
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• 2018

Corpus luteum (CL) is a transient endocrinal tissue that undergoes repeated formation and regression during the estrous cycle. In this study, we hypothesized that the functional and structural mechanism of angiogenesis is similar between CL and tumor formation. First, we measured mRNA and protein expression of angiogenic receptors (vascular endothelial growth factor receptor-2, VEGFR2; Tie 2) in the early, middle, and late phase CL tissues during the estrous cycle. Ral-interacting protein of 76 kDa (RLIP76) and H-ras mRNA and protein were also expressed in the CL tissues. VEGFR2 and Tie 2 mRNA and protein were expressed in the early and middle phase CLs and decreased in the late phase. H-ras mRNA and protein were expressed in the early and middle phase CLs, but not in the late phase. RLIP76 mRNA was expressed in all phase CLs, and the protein expression was highest in early phase CLs. We suggest that RLIP76 and H-ras, an oncogenic gene, regulate the function of the CL during the estrous cycle, and the proteins will play an important role in the angiogenic mechanism of the CL.

• Journal of Life Science
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• v.8 no.1
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• pp.60-66
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• 1998

The mototic and meiotic chromosomal characteristics of ICR mice were investigated with G-and C-banding techniques. For the puposes, the chromosomal preparations were made with the modified air-drying method of Imal et al. Chromosomal analysis using testis could be observed mitotic as well as meitotic chromosomal behaviors, and the centromeric regions of all chromosomes including X chromosome were strongly stained in C-banded preparations. Nineteen autosomal bivalents and a single uniequal terminally associated X-Y bivalent in normal cells were observed during the late prophase and the metaphase of the meiosis I. The mean frequencies of previously dissociated X-Y chromosomes in the primary apermatocytes of the control group were 7.45%, but the frequencies of X-Y dissociation in the alkylating agents-treated group were about 3-4 times higher than that in the control group. Application of C-banding in meiotic stages could be certainly distinguish between vibalent type and univalents type of sex chromosomes.

• Microbiology and Biotechnology Letters
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• v.14 no.2
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• pp.175-179
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• 1986

In order to develope a protoplast fusion of the genus Cellulomonas having high assimilibility of cellulose, the optimum conditions for the protoplast formation of Cellulomonas flavigena NCIB 12901 was investigated and observed by means of Scanning Electron Microscope. The results suggested that the susceptibility of the cell wall by lysozyme treatment on protoplast formation was considerably depend on the cultural periods of the cells. Cells of C. flavigena at mid exponential phase could more efficiently convert to protoplast cells than those at late exponential phase did. The rate of the protoplast formation was 95%, even though the rate was over 99.9% on counting by indirect method after osmotic shock treatment, when cells of the organism at mid exponential phase were treated with lysozyme (400$\mu\textrm{g}$/$m{\ell}$) for 6 hours and observed by SEM. In the evaluation of protoplast formation of the genus Cellulomonas, direct method of the observation under Scanning Electron Microscope was much more reliable than the counting method of protplasts after osmotic shock treatment. Because defferences between the number of spheroplast and protoplast were not able to be figured out on counting the number of protoplast after osmotic shock treatment.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.247-259
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• 2008

Terminal-restriction fragment length polymorphism (T-RFLP) analysis, one of rapid culture-independent microbial community analysis methods, was used to determine the lactic acid bacterial complexity and dynamics during kimchi fermentation at $15^{\circ}C$ and $4^{\circ}C$. At both temperatures, the common presence of Leuconostoc mesenteroides, Lc. inhae, Lc. kimchi, Weissella koreensis, W. cibaria, Lactobacillus sakei, Lb. curvatus, Lb. plantarum, Lb. paraplantarum, Lb. pentosus, and Lb. brevis was predicted. Lc. citreum and Enterococcus faecalis were detected at $15^{\circ}C$ and $4^{\circ}C$, respectively. W. koreensis predominated during the mid stage of kimchi fermentation whereas lactobacilli were dominants during later stage. Lb. sakei and Lb. curvatus became dominants regardless of fermentation temperature but the growth of Lb. plantarum, Lb. paraplantarum, Lb. pentosus, and Lb. brevis was restricted at psychrophilic temperature. Some species of leuconostocs were maintained until the later stage of kimchi fermentation.

• Microbiology and Biotechnology Letters
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• v.17 no.2
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• pp.94-99
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• 1989

Seven gtrains of Lactobacillus produce bacteriocin being active for Lacidophilus. All strains producing bacteriocin were found to be L. acidophilus except with one strain of L. gasseri. The maximum activity of bacteriocin produced by Lactobacillus strains was obtained at a middle or late stage of the log phase, or a early stage of the stationary phase. After the maximum was reached, however, the activity was rapidly decreased. The bacteriocins were inactivated easily by the treatment with proteolytic enzymes but not with nucleolytic enzymes, suggesting that the bacteriocin was proteinaceous. The bacteriocins were different from the other previously reported lactobacillus bacteriocin in their flexibility to the treatment at 10$0^{\circ}C$. Bacteriocins of L. acidophilus ATCC 9857 and 4357 decreased in activity by the treatment with diethylether, presumably the bacteriocin contained of a lipid component. It sums likely that L. acidophilus A4 bacteriocin adsorb to a regularly arrayed layer of the cell wall.

• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.327-333
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• 1988

For optimal production of recombinant human interleukin-2 (IL-2) in E. coli the effect of fermentation conditions on cell growth, IL-2 production, and stability of recombinant cells were investigated. Among the complex nutrients tested in this work, yeast extract, peptone and corn steep liquor were found to be effective for recombinant cell growth. The recombinant cells were maintained stably under repression condition (3$0^{\circ}C$), but the stability of recombinant cells were drastically reduced upon induction of IL-2 expression (42$^{\circ}C$) even under the selection pressure. Addition of antibiotics to the culture medium resulted in the cell growth inhibition without significant improvement in recombinant stability. When the expression of IL-2 gene was induced at different growth phases, highest IL-2 production was achieved by the induction of IL-2 at the middle-exponential growth phase. It was found that the production of IL-2 significantly inhibited the cell growth and the ex-pression of other genes in the plasmid.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.251-257
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• 1986

Optimum conditions for the protoplast formation and regeneration of Lactobacillus casei have been searched for. L. casei cells were converted to protoplast by treating with 10$\mu\textrm{g}$/$m{\ell}$ of mutanolysin in 20mM potassium phosphate buffer (pH6.8) containing 6mM CaCl$_2$, 6mM MgCl$_2$ and 1M sucrose. Maximum number of protoplasts was obtained when cells were taken from Tomochika's medium containing 0.5% glycine at the middle to late logarithmic growth phase. Regeneration was efficiently accomplished on the regeneration medium containing 6mM CaCl$_2$, 6mM MgCl$_2$, 0.8M sucrose and 10% of horse serum. The efficiently of the cell wall regeneration from protoplasts was 2-5% after 3-4 days of incubation at 3$0^{\circ}C$.

• Journal of Life Science
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• v.14 no.2
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• pp.235-238
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• 2004

The possibility for developing multistage culture system to cultivate larvae by computer simulation with basic experiments was investigated. This culture system was composed of 3 stages. At the 1st stage, Chlorella sp. were cultivated and at 2nd stage Chlorella sp. were supplied to rotifer (Brachionus plicatilis), and rotifer were supplied to larvae at the 3rd stage. In this study, Chlorella sp. were cultivated by batch culture to search for the possibility of continuous feeding to rotifer at 2 nd stage. The maximum specific growth rate ($\mu$$_{max}$) of Chlorella sp. at the logarithmic phase was 0.56 [1/day]. Rotifer was cultivated by fed-batch culture at the feeding rate of Chlorella sp., $10^3$, $10^4$, $10^{5}$ and $10^{6}$ [cells/rotiferㆍh] to search for the relation between the feeding rate of Chlorella sp. and the growth rate of rotifer. As the results, the minimum feeding rate of Chlorella sp. was 2.8 ${\times}$ $10^4$ [cells/rotiferㆍday] in the multistage culture system, then the change of rotifer concentration at 2nd stage was simulated by computer. The required amount of rotifer for the growth of larvae was also increased as the growth of larvae. On the 9th day of the culture, the rotifer uptake rate of larvae was 250 [cells/rotiferㆍday]. Based on these basic experiments and results, It was suggested that the possibility of multistage culture system to cultivate larvae with continuous feeding of Chlorella sp. and rotifer.r.