• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.424-429
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• 2008

To investigate the acid tolerance characteristics of the acid-resistant mutant, Leuconostoc paramesenteroides P-200, as a kimchi starter, this study examine proton permeability, ATPase activity, glycolysis activity, $Mg^{2+}$ release, and membrane fatty acid composition, and compared the data to that of its wild-type, L. paramesenteroides LP-W. In the proton permeability experiment, the LP-W and P-200 strains' average maximum half-time $(t_{1/2})$ values for pH equilibration through the cell membrane were approximately 5.7 and 9.3 min in 150mM KCl solution, and 4.2 and 8.3 min in 3% NaCl solution, respectively. Their values and pH levels for maximal specific ATPase activity showed that P-200 had greater activity than LPW. And the results of pH-dependent glycolysis activity showed that P-200 had greater activity than LP-W. Furthermore, after 2 hr at pH 4.0, LP-W and P-200 had percent magnesium release values of approximately 12% and 34%, respectively. A comparison of their membrane fatty acid compositions indicated that C18 and cyclo-C19 were the major different fatty acids between the two strains, and their contents of C18 and cyclo-C19 were 2.5% and not detected, respectively, in LP-W, and 6.4% and 11.4%, respectively, in P-200. These results indicate that the P-200 strain has significantly improved acid tolerance as compared to its wild type, LP-W.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.102-109
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• 1998

To investigate the increased acid tolerance of a acid-resistant mutant Leuconostoc mesenteroides M-100 improved as a kimchi starter, proton permeability, ATPase acitivity, glycolysis activity, $Mg^{2+}$ releasement, and membrane fatty acid composition were studied and comprised with its wild type Leuconostoc mesenteroides Mw. In the proton permeability experiment, the mininum values of the average half time ($t_{1/2}$) of pH equilibration through the cell membrane of the Mw and the M-100 were about 8.6 min and 9.2 min in 150 mM KCI solution, respectivily. In the 3% NaCl solution, the $t_{1/2}$ values of the Mw and the M-100 were 6min and 8.6 min, respectivily. The values and pHs of maximal specific activities of ATPase originated from the Mw and the M-100 were 0.6U at pH 5.5 and 0.8U at pH 5.5, respectivily. The result of pH dependence of glycolysis showed that the M-100 had higher activities than that of Mw except at pH 5.0. The releases of magnesium from the Mw and the M-100 were observed about 36.5% and 13% at pH 4.0 after 2 hours, respectivily. The results of comparison of membrane fatty acid composition of the Mw with the M-100 showed that $C_{12}$, $C_{14}$, $C_{18:1}$, and $C_{19:0cyclo}$ were major different fatty acids between two strains and the content of $C_{18:1}$, and $C_{19:0cyclo}$ were 23.4%, 10.2% in the Mw and 15.1%, 12.2% in the M-100. These results indicated that acid tolerance of the M-100 was significantly improved in comparison with its wild type Mw.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.275-282
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• 1998

To investigate the increased acid tolerance of a acid-resistant mutant Leuconostoc paramesenteroides P-100 improved as a kimchi starter, proton permeability, ATPase acitivity, glycolysis activity, $Mg^2$sup +/ releasement, and membrane fatty acid composition were studied and comprised with its wild type Leuconostoc paramesenteroides Pw. In the proton permeability experiment, the maximum values of the average half time (t$\_$1/2/) of pH equilibration through the cell membrane of the Pw and the P-100 were about 6.4 min and 7.8 min in 150 mM KCI solution, respectively. In the 3% NaCl solution, the t$\_$1/2/ values of the Pw and the P-100 were 5.5 min and 6.9 min, respectively. The values and pHs of maximal specific activities of ATPase originated from the Pw and the P-100 were 0.5 unit/mg protein and 0.78 unit/mg protein at pH 6.0, respectively. The result of pH dependence of glycolysis showed that the P-100 had higher activities than that of Pw except at pH 7.0. The releases of magnesium from the Pw and the P-100 were observed about 54.5% and 23.2% at pH 4.0 after 2 hours, respectively. The results of comparison of membrane fatty acid composition of the Pw with the P-100 showed that C$\_$8:0/, C$\_$9:0/, C$\_$10:0/, C$\_$11:0/, C$\_$18:0/, and C$\_$19:0,cyclo/ were major different fatty acids between two strains and the content of C$\_$18:1/, and C$\_$19:0,cyclo/ were 2.8%, N.D (not detected) in the Pw and 0.4%, 2.3% in the P-100. These results indicated that acid tolerance of the P-100 was significantly improved in comparison with its wild type Pw.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.246-253
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• 2017

Objective: Present study explores the effect of hot summer period on the glycolytic rate of early post-mortem meat quality of Ghungroo and Large White Yorkshire (LWY) pig and comparative adaptability to high temperature between above breeds by shifting the expression of stress related genes like mono-carboxylate transporters (MCTs) and heat shock proteins (HSPs). Methods: Healthy pigs of two different breeds, viz., LYW and Ghungroo (20 from each) were maintained during hot summer period (May to June) with a mean temperature of about $38^{\circ}C$. The pigs were slaughtered and meat samples from the longissimus dorsi (LD) muscles were analyzed for pH, glycogen and lactate content and mRNA expression. Following 24 h of chilling, LD muscle was also taken from the carcasses to evaluate protein solubility and different meat quality measurements. Results: LWY exhibited significantly (p<0.01) higher plasma cortisol and lactate dehydrogenase concentration than Ghungroo indicating their higher sensitivity to high temperature. LD muscle from LWY pigs revealed lower initial and ultimate pH values and higher drip loss compared to Ghungroo, indicating a faster rate of pH fall. LD muscle of Ghungroo had significantly lower lactate content at 45 min postmortem indicating normal postmortem glycolysis and much slower glycolytic rate at early postmortem. LD muscle of LWY showed rapid postmortem glycolysis, higher drip loss and higher degrees of protein denaturation. Ghungroo exhibited slightly better water holding capacity, lower cooking loss and higher protein solubility. All HSPs (HSP27, HSP70, and HSP90) and MCTs (MCT1, MCT2, and MCT4) in the LD muscle of pigs inclined to increase more in Ghungroo than LWY when exposed to high temperature. Conclusion: Effect of high temperature on the variation of HSPs and MCTs may play a crucial role in thermal tolerance and adaptation to different climatic conditions, pH regulation, muscle acidification, drip loss, protein denaturation and also in postmortem meat quality development.

• Korean Journal of Poultry Science
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• v.6 no.1
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• pp.24-30
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• 1979

1. The effects of heat stress (38$^{\circ}C$), cold stress (4$^{\circ}C$) and extreme cold stress (-20$^{\circ}C$) before slaughter on the tenderness and postmortem glycolysis if the excised chicken breast muscle were studied Heat stress significantly (p 0.05) increased the toughness of breast muscle. Though statistically not significant, cold stress also adversely affected the tenderness. The heat-stressed birds showed higher zero hr glycogen higher zero hr pH and significantly (p 0.05) love. ultimate pH then the controls. The cold-stressed birds showed intermediate values in these parameters. Highly significant correlations. were observed between shear value and each of these three parameters. Glycolysis rate ana final moisture content were minor factors which affected the muscle tenderness to a limited extent. The slightly elevated lactate-dehydrogenase and creatine phosphokinase activities in serum and breast muscle of stressed birds failed to account for any variations in tenderness. 2. Chicken breast and thigh muscles were subjected to different environmental temperatures to determine if the phenomenon of cold shortening exists in chicken muscle. For both breast and thigh muscles, minimum shortening was observed in the 4-10$^{\circ}C$t range. Muscles held at 0$^{\circ}C$ showed a slightly higher extent of shortening than at 4$^{\circ}C$; where as muscles held at above 20$^{\circ}C$ showed a severe shortening effect. It was concluded that no apparent cold shortening was detected in chicken muscle except at 0$^{\circ}C$ and even at 0$^{\circ}C$ and even at 0$^{\circ}C$ the extent of shortening was of a small magnitude compared to bovine muscles. Since high temperature induces a much greater shortening, muscle temperature must be lowered to below 20$^{\circ}C$ as early as possible to prevent excessive muse]e shortening.

• Applied Biological Chemistry
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• v.30 no.4
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• pp.364-370
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• 1987

The $O_2^-$ level of the extract from young rice leaves, which was cold treated for 2 days and then placed at room temperature for a period of time significantly higher than that from tissues untreated. $O_2^-$ level in leaves was practically unchanged during cold treatment for 48 hours. But it started to increase to arrive at maximum in 8 hours, once the plants were placed under room temperature. The abnormal production of $O_2^-$ in mitochondria during postchilling process was interpreted as a biochemical consequence of accumulation of glycolysis product(s) in cytosol and/or NADH in mitochondrial matrix due to disruption of catabolic balance at low temperature. Mitochondria isolated from the chilling injured tissue was found to have lost considerably their respiratory activity. This fact may imply the involvement of intramitochondrial accumulation of $O_2^-$ in the inactivation of electron transport chain system. The observation that mitochondria in the presence of the $O_2^--producing$ enzymatic system (Xanthine/Xanthine oxidase) lost their respiratory activity supports this inference. It was also found in this work that Superoxide dismutase (SOD) is a substrate inducible enzyme, and that SOD is a possible protective agent in plant cell against chilling injury.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1369-1373
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• 2014

Objectives: To study application of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) with $^{18}F$-FDG PET/CT for predicting prognosis of esophageal squamous cell cancer (ESC) patients. Methods: Eighty-six patients with ESC staged from I to IV were prospectively enrolled. Cisplatin-based chemoradiotherapy (CCRT) or palliative chemoradiotherapy were the main treatment methods and none received surgery. $^{18}F$-FDG PET/CT scans were performed before the treatment. SUVmax, MTV, and TLG were measured for the primary esophageal lesion and regional lymph nodes. Receiver operating characteristic curves (ROCs) were generated to calculate the P value of the predictive ability and the optimal threshold. Results: MTV and TLG proved to be good indexes in the prediction of outcome for the ESC patients. An MTV value of 15.6 ml and a TLG value of 183.5 were optimal threshold to predict the overall survival (OS). The areas under the curve (AUC) for MTV and TLG were 0.74 and 0.70, respectively. Kaplan-Meier analysis showed an MTV less than 15.6 ml and a TLG less than 183.5 to indicate good media survival time (p value <0.05). In the stage III-IV patient group, MTV could better predict the OS (P < 0.001), with a sensitivity and specificity of 0.80 and 0.67, respectively. Conclusions: Pre-treatment MTV and TLG are useful prognostic factors in nonsurgical ESC.

• Journal of Gastric Cancer
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• v.20 no.1
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• pp.60-71
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• 2020

Purpose: The utility of 18-fluordesoxyglucose positron emission tomography ([¹⁸F]-FDG-PET) combined with computer tomography or magnetic resonance imaging (MRI) in gastric cancer remains controversial and a rationale for patient selection is desired. This study aims to establish a preclinical patient-derived xenograft (PDX) based [¹⁸F]-FDG-PET/MRI protocol for gastric cancer and compare different PDX models regarding tumor growth and FDG uptake. Materials and Methods: Female BALB/c nu/nu mice were implanted orthotopically and subcutaneously with gastric cancer PDX. [¹⁸F]-FDG-PET/MRI scanning protocol evaluation included different tumor sizes, FDG doses, scanning intervals, and organ-specific uptake. FDG avidity of similar PDX cases were compared between ortho- and heterotopic tumor implantation methods. Microscopic and immunohistochemical investigations were performed to confirm tumor growth and correlate the glycolysis markers glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) with FDG uptake. Results: Organ-specific uptake analysis showed specific FDG avidity of the tumor tissue. Standard scanning protocol was determined to include 150 μCi FDG injection dose and scanning after one hour. Comparison of heterotopic and orthotopic implanted mice revealed a long growth interval for orthotopic models with a high uptake in similar PDX tissues. The H-score of GLUT1 and HK2 expression in tumor cells correlated with the measured maximal standardized uptake value values (GLUT1: Pearson r=0.743, P=0.009; HK2: Pearson r=0.605, P=0.049). Conclusions: This preclinical gastric cancer PDX based [¹⁸F]-FDG-PET/MRI protocol reveals tumor specific FDG uptake and shows correlation to glucose metabolic proteins. Our findings provide a PET/MRI PDX model that can be applicable for translational gastric cancer research.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.488-494
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• 2013

The anti-diabetic effect of green tea fermented by cheonggukjang was evaluated using KK-$A^y$ mice, an animal model of type 2 diabetes mellitus. Over a 90 day testing period, food and water intake decreased significantly in the group fed fermented green tea (FGT) and a group fed commercially available health functional food (PC), when compared with a diabetic control group (DC). The blood glucose levels of FGT mice were lower than in DC mice throughout the test period and were similar to the levels in PC after 60 days. Levels of Hemoglobin A1c (HbA1c) levels and insulin resistance were lower in mice of the FGT group than in mice of the DC group. DNA microarray analysis showed that administration of FGT increased the abundance of 12 mRNA transcripts related to diabetes. Whereas FGT increased hexokinase transcripts related to glycolysis more than 37 fold, levels of Pdx1 (pancreatic and duodenal homeobox1) and Cacna1e (calcium channel) transcripts increased more than 1.8 fold.

• Journal of Life Science
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• v.25 no.5
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• pp.507-514
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• 2015

D-Xylulose is phosphorylated to D-xylulose-5-phosphate by D-xylulose kinase before it enters glycolysis via the nonoxidative pentose phosphate pathway. A gene encoding a novel D-xylulose kinase (XK) from K. gwangalliensis strain SJ2 was sequenced and expressed in E. coli. The sequence of the isolated XK gene was 1,419 bp, encoding 472 amino acids. The XK protein was more closely related to the Arthrobacter phenanthrenivorans XK than to the Bifidobacterium catenulatum one, as reflected in the sequence identity (54.9% vs. 38.7%). The XK gene was subcloned into the pCold-II expression vector. The resulting plasmid was transformed into E. coli strain BL21 (DE3) cells and the expression of the recombinant XK protein was induced by the addition of IPTG. The resulting protein was expressed as a fusion protein of approximately 48 kDa containing a N-terminal six-histidine extension that was derived from the expression vector. The expressed protein was homogenized by affinity chromatography and showed enzymatic activity corresponding to D-xylulose kinase. XK enzyme kinetic studies with D-xylulose and ATP showed a Km of 250±20 μM and 1,300±50 μM, respectively. The results obtained from this study will provide a wider knowledge base for the characterization of D-xylulose kinase at the molecular level.