• Journal of Microbiology and Biotechnology
• /
• 제25권1호
• /
• pp.81-88
• /
• 2015

This study describes a novel strategy to regulate the metabolic flux for lactic acid production in Lactobacillus casei. The ldhL gene encoding _L-lactate dehydrogenase (L-LDH) was overexpressed in L. casei, and a two-stage oxygen supply strategy (TOS) that maintained a medium oxygen supply level during the early fermentation phase, and a low oxygen supply level in the later phase was carried out. As a consequence, a maximum L-LDH activity of 95.6 U/ml was obtained in the recombinant strain, which was over 4-fold higher than that of the initial strain. Under the TOS for L. casei (pMG-ldhL), the maximum lactic acid concentration of 159.6 g/l was obtained in 36 h, corresponding to a 62.8% increase. The results presented here provide a novel way to regulate the metabolic flux of L. casei for lactic acid production in different fermentation stages, which is available to enhance organic acid production in other strains.

• Journal of Microbiology and Biotechnology
• /
• 제21권2호
• /
• pp.162-169
• /
• 2011

A dynamic model of lactic acid fermentation using Lactococcus lactis was constructed, and a metabolic flux analysis (MFA) and metabolic control analysis (MCA) were performed to reveal an intensive metabolic understanding of lactic acid bacteria (LAB). The parameter estimation was conducted with COPASI software to construct a more accurate metabolic model. The experimental data used in the parameter estimation were obtained from an LC-MS/MS analysis and time-course simulation study. The MFA results were a reasonable explanation of the experimental data. Through the parameter estimation, the metabolic system of lactic acid bacteria can be thoroughly understood through comparisons with the original parameters. The coefficients derived from the MCA indicated that the reaction rate of L-lactate dehydrogenase was activated by fructose 1,6-bisphosphate and pyruvate, and pyruvate appeared to be a stronger activator of L-lactate dehydrogenase than fructose 1,6-bisphosphate. Additionally, pyruvate acted as an inhibitor to pyruvate kinase and the phosphotransferase system. Glucose 6-phosphate and phosphoenolpyruvate showed activation effects on pyruvate kinase. Hexose transporter was the strongest effector on the flux through L-lactate dehydrogenase. The concentration control coefficient (CCC) showed similar results to the flux control coefficient (FCC).

• 한국식품영양학회지
• /
• 제14권4호
• /
• pp.355-359
• /
• 2001

The purpose of this study was to compare the level of blood glucose and lactate and also plasma LDH production of college women in relation to exercise. College female student which majored athletics (E, exercise group, n=43) were recruited and compared with college women (Control group, n=60). Anthropometric measurements, triceps skinfold thickness were measured of two groups. And body fat mass and waist and hip circumferences were measured and the concentrations of plasma glucose, lactic acid and lactic acid dehydrogenase (LDH) were also assayed. Average height and weight of E group were slightly higher than that of control group. but there is no difference in body mass index (BMI) and waist hip ratio (WHR) between two groups. The percentage of body fat and body fat mass(kg) in E group was slightly lower than that of control group. Plasma glucose and LDH levels of E group were higher than those of control group, and plasma lactic acid concentration was significantly increased.

• Journal of Nutrition and Health
• /
• 제4권1호
• /
• pp.21-28
• /
• 1971

1. The effects of chloroform to the tissue lactic dehydrogenase (LDH) activities and its isozymes and to the tissue glutamic dehydrogenase (GDH) activities and its isoaymes are studied using the experimental albino male adult rats in this paper. The tissues studies are liver, kidney, heart, and brain. Besides the control group, two experimental groups are studied providing succeedingly 4 days interpariental administrations of chloroform, 0.0025ml and 0.025ml per day respectively. The changes of body weights, weights of organs, activities of GDH and LDH and their isozymes of each tissues, are analysed. 2. The body weights of rats are decreased due to the chloroform administration. 3. There are no significant differences of weights of organs due to the chloroform administration. 4. The significant decreases of tissue GDH activities and the significant changes in percent distribution of the GDH isozymes are found due to the chloroform administration. This weight be interpretated that chloroform effects to the protein and amino acid metabolism of rats. 5. Due to the chloroform administration, the significant changes in tissue LDH activities and in percent distribution of tissue LDH isozymes indicating the decreases of $LDH_1$ which is the aerobic heart type and the increase of $LDH_5$ which is the anaerobic muscle type, are observed. This could be estimated that chloroform effects to the carbohydrate metabolism, particularly to the anaerobic glycolysis of rats.

• Journal of Biosystems Engineering
• /
• 제30권4호
• /
• pp.249-253
• /
• 2005

This study was carried out to develop enzyme biosensor for lactic acid bacteria. Lactic acids produced by lactic acid bacteria (LAB) was measured and good correlation $R^2=0.98$ between LAB count and lactic acids concentration was found. Hydrogen ion produced by L-lactate dehydrogenase (L-LDH) was measured by a potentiometer. Glutamic-pyruvic transminase (GPT) was used for eliminating inhibitor in the reaction. Polyacrylamide gel was used for immobilizing matrix of the sensor. The biosensor was tested and showed good feasibility with $R^2=0.99$ on validation.

• 대한치과의사협회지
• /
• 제10권1호
• /
• pp.15-21
• /
• 1972

백서의 전치를 주기적으로 절제후 치수내의 LDH isoenzyme을 전기영동법으로 분리하고 그의 활성도를 측정하여 정상과 비교관찰한바 다음과 같은 결론을 얻었다. 1. 정상치수내에서 5개의 LDH isoenzyme의 존재를 확인하였다. 2. LDH 활성도는 주기적으로 절제한 치아의 치수가 정상치수에 비해 훨씬 증가하였다. 3. 치아를 주기적으로 절제함으로써 치수내 LDH isoenzyme의 Pattern을 변화시킬 수가 있다.

• The Korean Journal of Physiology and Pharmacology
• /
• 제25권6호
• /
• pp.517-523
• /
• 2021

The present study aims to investigate the impact of hydrogen-rich water on the lactic acid level in metformin-treated diabetic rats under hypoxia. Thirty Sprague-Dawley rats were randomly divided into five groups, including normal diet group, and diabetes model (DM) group, DM + metformin treatment (DMM) group, DMM + hypoxia treatment (DMMH) group and DMMH + hydrogen-rich water (DMMHR) group. We found that the levels of lactic acid, pyruvate and lactate dehydrogenase were significantly lower in the blood of DMMHR group than DMMH group. Superoxide dismutase and glutathione levels in liver and heart were significantly higher in DMMH group after hydrogen-rich water treatment, while malondialdehyde and oxidized glutathione levels were decreased in DMMHR group when compared with DMMH group, which indicates that hydrogen-rich water could reduce oxidative stress. qPCR analysis demonstrated that that pro-apoptotic genes Bax/Caspase-3 were upregulated in DM group and metformin treatment suppressed their upregulation (DMM group). However, hypoxic condition reversed the effect of metformin on apoptotic gene expression, and hydrogen-rich water showed little effect on these genes under hypoxia. HE staining showed that hydrogen-rich water prevented myocardial fiber damages under hypoxia. In summary, we conclude that hydrogen-rich water could prevent lactate accumulation and reduce oxidant stress in diabetic rat model to prevent hypoxia-induced damages. It could be served as a potential agent for diabetes patients with metformin treatment to prevent lactic acidosis and reduce myocardial damages under hypoxic conditions.

• 대한약리학회지
• /
• 제25권1호
• /
• pp.75-85
• /
• 1989

면역 보체가 결합되어 있는 zymosan에 의하여 활성화된 다형핵 백혈구에서 세포 투과성 물질인 N-ethylmaleiamide과 $Hg^{++}$은 superoxide 라디칼 생성, NADPH oxidase 활성도 및 lysosomal enzyme (lactic dehydrogenase, ${\beta}-glucuronidase$)의 유리를 억제하였다. 세포막 단백에 특이적인 p-chloromercuribenzoic acid와 p-chloromercuribenzenesulfonic acid는 superoxide 라디칼 생성에 영향을 주지 않았으나 NADPH oxidase 활성도와 lysosomal enzyme의 유리를 억제하였다. 식작용 중에 세포막과 세포내의 sulfhydryl기는 반응시간에 따라 점진적으로 감소하였다. N-ethylmaleiamide와 $Hg^{++}$은 세포막과 세포내의 sulfhydryl기를 모두 감소시켰다. P-Chloromercuribenzoic acid와 p-chloromercuribenzenesulfonic acid는 세포막의 sulfhydryl기를 유의하게 감소시켰으나 세포내 용해성 sulfhydryl기에는 영향을 주지않았다. Cysteine과 mercaptopropionylglycine는 superoxide 라디칼의 생성과 lysosomal enzyme의 유리를 억제하였다. Gluthathione은 superoxide생성에 영향을 주지 않았으나 뚜렷하게 lactic dehydrogenase의 유리를 억제하였다. N-ethylmaleiamide에 의한 superoxide 생성의 억제는 cysteine과 mercaptopropionyl-glycine에 의하여 반전되었으나 gluthathione의 영향은 없었다. N-ethylamleiamide에 의한 NADPH oxidase의 비활성화는 gluthathione, cysteine과 mercaptopropionylglycine에 의하여 저해되었다. Carbachol에 의하여 항진된 superoxide 라디칼 생성은 N-ethylamleiamide에 의하여 완전히 억제되었고, atropine에 의하여 길항되었다. 그러므로, 외부 자극에 대한 다형핵 백혈구 반응의 표현은 sulfhydryl기의 양의 변화와 연관이 있을 것으로 시사되었다. Lysosomal enzyme 유리는 세포막과 세포내의 sulfhydryl기에 의하여, 이에 반하여 superoxide생성은 세포내 sulfhydryl기에 의해서 영향받을 것으로 추정되었다.

• 대한약리학회지
• /
• 제16권2호
• /
• pp.31-38
• /
• 1980

Calvert et al. formulated the hypothesis that carbon tetrachloride ($CCl_4$) acted on the central nervous system to produce and intensify sympathetic discharge which resulted in anoxic necrosis of the liver. Recknagel suggested that the essential feature of $CCl_4$ hepatotoxicity depended on the cleavage of it to $CCl_3$(free radical) and the peroxidative decomposition of cytoplasmic membrane structural lipids. And there are many reports which show the increase of adrenergic activity in hyperthyroidism. In this paper, the influence of thyroxine on the hepatotexicity of carbon tetrachloride was investigated in mice. The results obtained were summarized as follows; 1) Hepatic total lipid and lipid peroxide contents were slightly decreased by L-sodium thyroxine injection(4mg/kg/day for 4days or 6days), but hepatic glycogen content was significantly decreased. 2) Hepatic total lipid and lipid peroxide contents and serum lactic dehydrogenase activity were significantly increased by $CCl_4$ (4 ml/kg single dose or triple dose: 4ml/kg/day for 3days), but hepatic glycogen content was significantly decreased. 3) The increase of hepatic total lipid and lipid peroxide contents and serum lactic dehydrogenase activity induced by $CCl_4$ were significantly inhitited by the pretreatment of thyroxine. 4) The decrease of hepatic glycogen induced by $CCl_4$ was not affected by the pretreatment of thyroxine.

• Advances in Traditional Medicine
• /
• 제5권2호
• /
• pp.156-159
• /
• 2005

The protective effect of Naoxingtong (NXT) on rat cerebral microvascular endothelial cell (rCMEC) was investigated. rCMEC was injured in vitro by incubating for 4 hours at 100% NO in a hypoxia chamber. After treated with NXT-containing serum, the cellular viability rate (90.3%) was significantly elevated when compared with that of control group and the inhibitive rate of lactic dehydrogenase activity (9.2%) was far lower than the control group with dose-dependent effect. The results indicate that NXT can increase viability of rCMEC, and protect cell membrane from injury during hypoxia.