• Biotechnology and Bioprocess Engineering:BBE
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• 제7권2호
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• pp.105-111
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• 2002

The biological removal of 2,4,6-trinitrotoluene (TNT) was studied in a bench-scale bioreactor using a bacterial culture of strain OK-5 originally Isolated from soil samples contaminated with TNT. The TNT was completely removed within 4 days of incubation in a 2.5 L bench-scale bioreactor containing a newly developed medium. The TNT was catabolized in the presence of different supplemented carbons. Only minimal growth was observed in the killed controls and cultures that only received TNT during the incubation period. This catabolism was affected by the concentration ratio of the substrate to the biomass. The addition of various nitrogen sources produced a delayed effect for the TNT degradation. Tween 80 enhanced the degradation of TNT under these conditions. Two metabolic intermediates were detected and identified as 2-amino-4, 6-dinitrotoluene and 4-amino-2, 6-dinitrotoluene based on HPLC and GC-MS analyses, respectively. Strain OK-5 was characterized using the BIOLOG system and fatty acid profile produced by a microbial identification system equipped with a Hewlett Packard HP 5890 II gas chromatograph. As such, the bacterium was identified as a Stenotrophomonas species and designated as Stenotrophomonas sp. OK-5.

• 약학회지
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• 제45권1호
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• pp.78-84
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• 2001

Heme oxygenase is a rate-limiting enzyme in heme catabolism that cleaves heme to form biliverdin, iron, and carbon monoxide. Heme oxygenase-1 is expressed in many types of cells and tissues and is highly induced in response to oxidative stress. Carbon monoxide, one of the products of heme oxygenase, can stimulate soluble guanylate cyclase and dilate the vascular smooth muscle. So, the induction of heme oxygenase by lipopolysaccharide (LPS)-induced oxydative stress and the effect of the resultant carbon monoxide on aortic contractility were examined in this study. Zinc protoporphyrine IX (ZnPP), a inhibitor of heme oxygenase, elicited weak contraction of thoracic aortic ring, and this effect was more potent in aorta of LPS-treated rats than control and was blocked by methylene blue. The hyperreactivity to ZnPP in LPS-treated group was blocked by co-treatment with aminoguanidine. In the aortic ring of LPS-treated rats, ZnPP didn't change the vasoreactivity to phenylephrine or acetylcholine. ZnPP elicited hyper-tensive effect in concious rats, and pretreatment with LPS did not affect this effect. Prazosin significantly diminished the hypertensive effect of ZnPP. These results indicate that LPS induced heme oxygenase in aotra, and the resultant carbon monoxide diminished the aortic reactivity to vasoconstrictor.

• BMB Reports
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• 제46권4호
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• pp.207-212
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• 2013

The main purpose of this study is to examine the effect of caffeine on lipid accumulation in human hepatoma HepG2 cells. Significant decreases in the accumulation of hepatic lipids, such as triglyceride (TG), and cholesterol were observed when HepG2 cells were treated with caffeine as indicated. Caffeine decreased the mRNA level of lipogenesis-associated genes (SREBP1c, SREBP2, FAS, SCD1, HMGR and LDLR). In contrast, mRNA level of CD36, which is responsible for lipid uptake and catabolism, was increased. Next, the effect of caffeine on AMP-activated protein kinase (AMPK) signaling pathway was examined. Phosphorylation of AMPK and acetyl-CoA carboxylase were evidently increased when the cells were treated with caffeine as indicated for 24 h. These effects were all reversed in the presence of compound C, an AMPK inhibitor. In summary, these data indicate that caffeine effectively depleted TG and cholesterol levels by inhibition of lipogenesis and stimulation of lipolysis through modulating AMPK-SREBP signaling pathways.

• 미생물학회지
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• 제27권4호
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• pp.334-341
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• 1989

Toluate 분해 플라스미드를 pseudomonase cepacia SUB37에서 분리하여 분자량은 한천 젤 전기영동으로 측정한 결과 79. (119kb)로 확인되었다. 이 TOL플라스미드는 Pseudomonas의 다른 균주와 다른 속의 균주에 전달되었다. m-toluate 분해에서 가장 중요한 역할을 하는 catechol-2,3-oxygenase 활성을 P. cepacia SUB37과 transconjugant의 조효소액으로부터 측정한 결과, P. putida mt 2에서와 같이, meta pathway를 거쳐 m-toluate를 분해하는 유전자들이 plasmid에 암호화됨을 알수 있었다. P. cepacia SUB37 유래의 새로운 TOL plasmid는 IncP-4 불화합성군에 속하였고, 이것은 아마도 P. putida의 IncP-9 그룹의 TOL 플라스미드의 유도체로 사료된다.

• 한국식품영양과학회지
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• 제24권4호
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• pp.487-492
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• 1995

The purpose of this study was to investigate the effect of vitamin B2 deficiency on fuel metabolism in streptozotocin-induced diabetic rats. Thirty rats were fed a vitamin B2 deticient diet(-B2) or a control diet (＋B2) for 2 weeks and then subdivided into 3 groups respectively : base group, one day diabetic group and three day diabetic group. Diabetes of the rats were induced by streptozotocin injection into the tail vein. Glucose, glycogen, protein, alanine, triglyceride and free fatty acid were compared in plasma, liver, skeletal muscle of rats. Also, the total urinary nitrogen and glucose excertion were compared. Compared with ＋B2 rats, the increase of plasm glucose in -B2 rats due to the diabetes tended to be smaller. After diabetes were induced, the levels of plasma protein and alanine was significantly decreased and the urinary nitrogen excretion was significantly increased in -B2 rats. The level of plasma free fatty acid was increased continuously in B2 rats while increased at the first day and decreased at the third day diabetes was induced in ＋B2 rats. These results suggest that vitamin B2 deficiency increase protein catabolism due to the decrease of fatty acid oxidation. Thus, vitamin B2 deficiency in diabetes impair the adaptation of animals to the fuel metabolism and aggravate the body protein wasting which is one of the chronic complications of diabetes.

• 한국식품영양학회지
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• 제12권1호
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• pp.43-49
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• 1999

The effects of purine catabolites in growth media on the Serratia marcescens purine nucleoside phos-phorylase activity were examined. The enzyme activity was decreased above 60% by guanosine(5 to 15mM). The enzyme activity was not affected at low concentration of inosine (0.1∼1mM). The en-zyme activity was decreased approximately by 40∼50% in the presence of high concentrations of aden-osine hypoxanthine and xanthine (5∼15mM) but was not affected at low concentration of adenosine hypoxanthine and xanthine (0.1∼0.5mM). However the enzyme activity was increase by 20% with low concentrations of uric acid(0.5mN). but was decreased by 80% with high concentrations of same purine catabolite (15mM). Also the enxzyme activity was increased by 20% with low concentrations of glyoxylate (0.5mM) final degradative product of uric acid but was decreased by 30∼50% with high con-centrations of glyoxylate (3∼15mM). The enzyme activity was decreased approximately by 20% by the simultaneous addition of inosine hypoxanthine and uricacid at 5mM each whereas it was increased by 22 and 33% by the combination of inosine and uric acid three purine catabolites at 0.5mM respectively These data suggest that S. marcescens purine nucleoside phosphorylase is positively regulated by a glyox-ylate concentration and then may play a regulatory role in a purine catabolism.

• Journal of Nutrition and Health
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• 제27권3호
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• pp.228-235
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• 1994

The purpose of this study was to investigate the effect of vitamin B6 deficiency on the concentration of energy metabolite in streptozotocin-induced diabetic rats. Thirty rats were fed a vitamin B6 deficient diet(-B6) or a control diet(+B6) for 5 weeks and then subdivided into 3 groups respectively ; base group, one day diabetic group and three day diabetic group. Diabetes of rats were induced by streptozotocin injection into the tail vein. Glucose, glycogen, protein, alanine, triglyceride and free fatty acids were compared in plasma, liver skeletal muscle of rats. Also, the total urinary nitrogen and glucose excretion were compared. Compared with +B6 rats, the increase of plasma glucose in -B6 rats due to the diabetes was smaller. After diabetes was induced, the level of plasma alamine was not changed in -B6 rats while increased significantly(p<0.05) in +B6 rats. The increase of urinary nitrogen excretion was smaller and the increase of muscle protein was larger in -B6 rats at the first day diabetes was induced. The levels of plasma free fatty acid and liver triglyceride were significantly (p<0.05) higher in -B6 rats after diabetes was induced. These results suggest that vitamin B6 deficiency may impair the adaptation of animals to the energy metabolism related due to a decrease of the body protein catabolism of fatty acid oxidation in diabetes and aggravate fatty liver which is one of the chronic complications of diabetes.

• Mass Spectrometry Letters
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• 제9권4호
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• pp.91-94
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• 2018

Bilin tetrapyrroles are metabolic products of the breakdown of porphyrins within a species. In the case of mammals, these bilins are formed by the catabolism of heme and can be utilized as either biomarkers in disease or as an indicator of human waste contamination. Although a small subset of bilin tandem mass spectrometry reports exist, limited data is available in online databases for their fragmentation. The use of fragmentation data is important for metabolomics analyses to determine the identity of compounds detected within a sample. Therefore, in this study, the fragmentation of bilins generated by positive ion mode electrospray ionization is examined by collision-induced dissociation (CID) as a function of collision energy on an FT-ICR MS. The use of the FT-ICR MS allows for high mass accuracy measurements, and thus the formulas of resultant product ions can be ascertained. Based on our observations, fragmentation behavior for hemin, biliverdin and its dimethyl ester, phycocyanobilin, bilirubin, bilirubin conjugate, mesobilirubin, urobilin, and stercobilin are discussed in the context of the molecular structure and collision energy. This report provides insight into the identification of structures within this class of molecules for untargeted analyses.

• Molecules and Cells
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• 제45권9호
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• pp.649-659
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• 2022

A long-term energy nutritional imbalance fundamentally causes the development of obesity and associated fat accumulation. Lysosomes, as nutrient-sensing and lipophagy centers, critically control cellular lipid catabolism in response to nutrient deprivation. However, whether lysosome activity is directly involved in nutrient-induced fat accumulation remains unclear. In this study, worm fat accumulation was induced by 1 mM glucose or 0.02 mM palmitic acid supplementation. Along with the elevation of fat accumulation, lysosomal number and acidification were also increased, suggesting that lysosome activity might be correlated with nutrient-induced fat deposition in Caenorhabditis elegans. Furthermore, treatments with the lysosomal inhibitors chloroquine and leupeptin significantly reduced basal and nutrient-induced fat accumulation in C. elegans. The knockdown of hlh-30, which is a critical gene in lysosomal biogenesis, also resulted in worm fat loss. Finally, the mutation of aak-2, daf-15, and rsks-1 showed that mTORC1 (mechanistic target of rapamycin complex-1) signaling mediated the effects of lysosomes on basal and nutrient-induced fat accumulation in C. elegans. Overall, this study reveals the previously undescribed role of lysosomes in overnutrition sensing, suggesting a new strategy for controlling body fat accumulation.

• Molecules and Cells
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• 제46권3호
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• pp.142-152
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• 2023

Nuclear factor erythroid 2-related factor 2 (Nrf2) mediates the cellular antioxidant response, allowing adaptation and survival under conditions of oxidative, electrophilic and inflammatory stress, and has a role in metabolism, inflammation and immunity. Activation of Nrf2 provides broad and long-lasting cytoprotection, and is often hijacked by cancer cells, allowing their survival under unfavorable conditions. Moreover, Nrf2 activation in established human tumors is associated with resistance to chemo-, radio-, and immunotherapies. In addition to cancer cells, Nrf2 activation can also occur in tumor-associated macrophages (TAMs) and facilitate an anti-inflammatory, immunosuppressive tumor immune microenvironment (TIME). Several cancer cell-derived metabolites, such as itaconate, L-kynurenine, lactic acid and hyaluronic acid, play an important role in modulating the TIME and tumor-TAMs crosstalk, and have been shown to activate Nrf2. The effects of Nrf2 in TIME are context-depended, and involve multiple mechanisms, including suppression of proinflammatory cytokines, increased expression of programmed cell death ligand 1 (PD-L1), macrophage colony-stimulating factor (M-CSF) and kynureninase, accelerated catabolism of cytotoxic labile heme, and facilitating the metabolic adaptation of TAMs. This understanding presents both challenges and opportunities for strategic targeting of Nrf2 in cancer.