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1.
Türker Y Nazıroğlu M Gümral N Celik O Saygın M Cömlekçi S Flores-Arce M 《Biological trace element research》2011,143(3):1640-1650
The aim of this study was to investigate the possible protective role of selenium and l-carnitine on oxidative stress induced by 2.45-GHz radiation in heart of rat. For this purpose, 30 male Wistar Albino rats
were equally divided into five groups namely controls, sham controls, radiation-exposed rats, radiation-exposed rats treated
with intraperitoneal injections of sodium selenite at a dose of 1.5 mg/kg/day, and radiation-exposed rats treated with intraperitoneal
injections of l-carnitine at a dose of 1.5 mg/kg/day. Except for the controls and sham controls, the animals were exposed to 2.45-GHz radiation
during 60 min/day for 28 days. The lipid peroxidation (LP) levels were higher in the radiation-exposed groups than in the
control and sham control groups. The lipid peroxidation level in the irradiated animals treated with selenium and l-carnitine was lower than in those that were only exposed to 2.45-GHz radiation. The concentrations of vitamins A, C, and
E were lower in the irradiated-only group relative to control and sham control groups, but their concentrations were increased
in the groups treated with selenium- and l-carnitine. The activity of glutathione peroxidase was higher in the selenium-treated group than in the animals that were
irradiated but received no treatment. The erythrocyte-reduced glutathione and β-carotene concentrations did not change in
any of the groups. In conclusion, 2.45-GHz electromagnetic radiation caused oxidative stress in the heart of rats. There is
an apparent protective effect of selenium and l-carnitine by inhibition of free radical formation and support of the antioxidant redox system. 相似文献
2.
Cancer cachexia causes metabolic alterations with a marked effect on hepatic lipid metabolism. l-Carnitine modulates lipid metabolism and its supplementation has been proposed as a therapeutic strategy in many diseases.
In the present study, the effects of l-carnitine supplementation on gene expression and on liver lipid metabolism-related proteins was investigated in cachectic
tumour-bearing rats. Wistar rats were assigned to receive 1 g/kg of l-carnitine or saline. After 14 days, supplemented and control animals were assigned to a control (N), control supplemented
with l-carnitine (CN), tumour-bearing Walker 256 carcinosarcoma (TB) and tumour-bearing supplemented with l-carnitine (CTB) group. The mRNA expression of carnitine palmitoyltransferase I and II (CPT I and II), microsomal triglyceride
transfer protein (MTP), liver fatty acid-binding protein (L-FABP), fatty acid translocase (FAT/CD36), peroxisome proliferator-activated
receptor-alpha (PPAR-alpha) and organic cation transporter 2 (OCTN2) was assessed, and the maximal activity of CPT I and II
in the liver measured, along with plasma and liver triacylglycerol content. The gene expression of MTP, and CPT I catalytic
activity were reduced in TB, who also showed increased liver (150%) and plasma (3.3-fold) triacylglycerol content. l-Carnitine supplementation was able to restore these parameters back to control values (p < 0.05). These data show that l-carnitine preserves hepatic lipid metabolism in tumour-bearing animals, suggesting its supplementation to be of potential
interest in cachexia. 相似文献
3.
This study shows the effects of l-carnitine treatment on cell proliferation with hepa1c1c7 mouse cancer cells and NCTC 1469 normal cells. In an MTT assay,
l-carnitine increased the number of dead hepa1c1c7 cells, while there was no difference in the number of NCTC 1469 cells. mRNA
and protein levels of TNF-α, Fas, and caspase-8, which are closely related to cell apoptosis by a death ligand/receptor-dependent
apoptosis pathway, were increased by l-carnitine treatment. In addition, l-carnitine treatment regulated mitochondria-dependent apoptosis pathways by inducing the up-regulation of caspase-9 and caspase-3
and the down-regulation of Bcl-2 in hepa1c1c 7 cells. Taken together, the findings of this study have demonstrated that l-carnitine could induce apoptosis in hepa1c1c7 cells by regulating Fas ligands and inhibiting the expression of Bcl-2. These
results suggest that l-carnitine treatment could be related to both a mitochondrion-dependent and a death ligand/receptor-dependent apoptosis pathway
in hepa1c1c7 cells. Our results could give information for understanding the l-carnitine-induced apoptosis mechanism in some cancer cells. 相似文献
4.
J. M. Obón J. R. Maiquez M. Cánovas H.-P. Kleber J. L. Iborra 《Applied microbiology and biotechnology》1999,51(6):760-764
The use of a biological procedure for l-carnitine production as an alternative to chemical methods must be accompanied by an efficient and highly productive reaction
system. Continuous l-carnitine production from crotonobetaine was studied in a cell-recycle reactor with Escherichia coli O44 K74 as biocatalyst. This bioreactor, running under the optimum medium composition (25 mM fumarate, 5 g/l peptone), was
able to reach a high cell density (26 g dry weight/l) and therefore to obtain high productivity values (6.2 g l-carnitine l−1 h−1). This process showed its feasibility for industrial l-carnitine production. In addition, resting cells maintained in continuous operation, with crotonobetaine as the only medium
component, kept their biocatalytic capacity for 4 days, but the biotransformation capacity decreased progressively when this
particular method of cultivation was used.
Received: 10 December 1998 / Received revision: 19 February 1999 / Accepted: 20 February 1999 相似文献
5.
Mukhtar Ahmed Nasser Al-Daghri Abdul Halim Harrath Majed S. Alokail Ravindranath H. Aladakatti Mukhtar Ahmed G. Ghodesawar Saleh Alwasel 《Comptes rendus biologies》2013,336(8):392-399
Boswellia papyrifera and Boswellia carterii, known as Arabian incense, diffuses smoke, contaminating the air, which adversely affects human health. Therefore, this study was designed to ascertain the effect of these plants on histopathological and ultrastructure changes in cauda epididymis of Albino rats. Animals were exposed to 4 g/kg body weight of B. papyrifera and B. carterii daily for 120 days along with suitable controls. Our study indicates a significant reduction in epithelial heights. Cells showed signs of degeneration. The ultrastructural study revealed that the cauda epididymis was affected, including its cell types. Furthermore, a decrease in the size of mitochondria, Golgi complex, and both ERs was observed. In all treated groups, plasma fructose decreased considerably, indicating the sign of reduced energy, vital for motility and other sperm functions. The results of this study suggest that these plants systematically affect cauda epididymal cell types and its lumen through its potential toxicity. 相似文献
6.
Characterization of epididymal sperm from Spix's yellow‐toothed cavies (Galea spixii Wagler, 1831) recovered by different methods
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Andréia Maria da Silva José Artur Brilhante Bezerra Lívia Batista Campos Érica Camila Gurgel Praxedes Gabriela Liberalino Lima Alexandre Rodrigues Silva 《Acta zoologica》2017,98(3):285-291
The aim of the present study was to characterize the epididymal sperm of Spix's yellow‐toothed cavy (Galea spixii) through two different recovery methods. Nine sexually mature males were euthanized and the complexes, testes–epididymis, were dissected. For each animal, one epididymis was processed by flotation method and the other was processed by retrograde flushing method, both using a TES‐based buffered media. After recovery, we evaluated the sperm for motility, vigour, viability, functional membrane integrity and morphology. Morphometric data from the different sperm regions were evaluated by using an appropriate software. After recovery, both methods provide similar values for all the sperm parameters, aiming the recovery of more than 300 × 106 sperm, presenting >50% motile sperm, with normal morphology and functional membrane. The total sperm length in this sperm was 48.87 ± 0.1, and the sperm head presented 9.4%, on average. A notable characteristic was the prominent acrosome found in the G. spixii sperm. In conclusion, we demonstrate that either flotation or retrograde flushing methods are suitable for the recovery of sperm from cauda epididymis of Spix's yellow‐toothed cavies. 相似文献
7.
Naidu GS Lee IY Cho OK Park YH 《Journal of industrial microbiology & biotechnology》2001,26(5):309-315
L -Carnitine is an ubiquitous substance that plays a major role in the transportation of long-chain fatty acids. We investigated
crucial factors that influence microbial conversion of γ-butyrobetaine to L-carnitine using an Achromobacter cycloclast strain. Two-stage culture results showed that γ-butyrobetaine induced enzymes essential for the conversion, which suggests
that the precursor should be present in the initial cell growth stage. The addition of yeast extract enhanced L-carnitine production whereas inorganic nitrogen sources inhibited it. Under nitrogen-limiting conditions, the cells accumulated
poly-β-hydroxybutyrate instead of L-carnitine. Among the trace elements tested, nickel addition enhanced L-carnitine production by almost twice that of the control and copper strongly inhibited the conversion. L-Carnitine production was reduced when the medium contained inorganic salts of sodium, potassium, and calcium at a concentration
greater than 2 g l−1. A higher L-carnitine yield was achieved when cells were incubated in a lower culture volume. The optimal pH for L-carnitine production was 5 to 5.5, whereas that of growth was 7.0, indicating that a pH shift was required. Under optimal
conditions, L-carnitine concentrations as high as 15 g l−1 were obtained in 62 h with a 45% molar conversion yield. Journal of Industrial Microbiology & Biotechnology (2001) 26, 309–315.
Received 26 November 2000/ Accepted in revised form 27 February 2001 相似文献
8.
Chang-Su Park Soo-Jin Yeom Yu-Ri Lim Yeong-Su Kim Deok-Kun Oh 《World journal of microbiology & biotechnology》2011,27(4):743-750
A putative ribose-5-phosphate isomerase (RpiB) from Streptococcus pneumoniae was purified with a specific activity of 26.7 U mg−1 by Hi-Trap Q HP anion exchange and Sephacryl S-300 HR 16/60 gel filtration chromatographies. The native enzyme existed as
a 96-kDa tetramer with activity maxima at pH 7.5 and 35°C. The RpiB exhibited isomerization activity with l-lyxose, l-talose, d-gulose, d-ribose, l-mannose, d-allose, l-xylulose, l-tagatose, d-sorbose, d-ribulose, l-fructose, and d-psicose and exhibited particularly high activity with l-form monosaccharides such as l-lyxose, l-xylulose, l-talose, and l-tagatose. With l-xylulose (500 g l−1) and l-talose (500 g l−1) substrates, the optimum concentrations of RpiB were 300 and 600 U ml−1, respectively. The enzyme converted 500 g l−1
l-xylulose to 350 g l−1
l-lyxose after 3 h, and yielded 450 g l−1
l-tagatose from 500 g l−1
l-talose after 5 h. These results suggest that RpiB from S. pneumoniae can be employed as a potential producer of l-form monosaccharides. 相似文献
9.
Sitta A Barschak AG Deon M de Mari JF Barden AT Vanzin CS Biancini GB Schwartz IV Wajner M Vargas CR 《Cellular and molecular neurobiology》2009,29(2):211-218
Aims
l-Carnitine exerts an important role by facilitating the mitochondrial transport of fatty acids, but is also a scavenger of
free radicals, protecting cells from oxidative damage. Phenylketonuria (PKU), an inborn error of phenylalanine (Phe) metabolism,
is currently treated with a special diet consisting of severe restriction of protein-enriched foods, therefore potentially
leading to l-carnitine depletion. The aim of this study was to determine l-carnitine levels and oxidative stress parameters in blood of two groups of PKU patients, with good and poor adherence to
treatment. Methods Treatment of patients consisted of a low protein diet supplemented with a synthetic amino acids formula not containing Phe,
l-carnitine, and selenium. l-Carnitine concentrations and the oxidative stress parameters thiobarbituric acid reactive species (TBARS) and total antioxidant
reactivity (TAR) were measured in blood of the two groups of treated PKU patients and controls. Results We verified a significant decrease of serum l-carnitine levels in patients who strictly adhered to the diet, as compared to controls and patients who did not comply with
the diet. Furthermore, TBARS measurement was significantly increased and TAR was significantly reduced in both groups of phenylketonuric
patients relatively to controls. We also found a significant negative correlation between TBARS and l-carnitine levels and a significant positive correlation between TAR and l-carnitine levels in well-treated PKU patients. Conclusions Our results suggest that l-carnitine should be measured in plasma of treated PKU patients, and when a decrease of this endogenous component is detected
in plasma, supplementation should be considered as an adjuvant therapy. 相似文献
10.
l-Carnitine when injected in mice 30 min before an LD100 of ammonium acetate (12 mmol/kg body weight, intraperitoneal) reduced mortality (100% survival with 16 mmoll-carnitine/kg) and prevented the appearance of symptoms of ammonia toxicity. Brain ammonia decreased in the animals givenl-carnitine. Ammonia decreased the levels of glutamate in brain; they were partially restored byl-carnitine, which also reduced the increase in brain glutamine in animals given only ammonia. The redox state of the brain was altered following ammonia intoxication. The ratio of lactate to pyruvate in the cytosol increased while that of glutamate to -ketoglutarate in the mitochondria decreased. These ratios were partially restored byl-carnitine. The implications of these findings are discussed relative to the mechanism of ammonia toxicity. 相似文献
11.
Joanna Saluk-Juszczak Beata Olas Barbara Wachowicz Rafal Glowacki Edward Bald 《Cell biology and toxicology》2010,26(4):355-365
The oxidative stress induced by acute exertion may interfere with blood platelet activation. The beneficial effect of l-carnitine (γ-trimethylamino-β-hydroxybutyric acid) on oxidative stress in blood platelets has not been fully investigated;
however, different studies indicate that this compound modulates platelet functions. The aim of our study was to assess the
effects of l-carnitine on platelet activation and oxidative/nitrative protein damage (determined by the levels of protein carbonyl groups,
thiol groups, and 3-nitrotyrosine residues) in resting blood platelets or platelets treated with peroxynitrite (ONOO−, a strong physiological oxidant) in vitro. We also investigated the effects of l-carnitine on the level of platelet glutathione and on the formation of superoxide anion radicals ( O2 - · ) \left( {{\hbox{O}}_2^{ - \bullet }} \right) , lipid peroxidation measured by thiobarbituric acid reactive substances (TBARS) in blood platelets stimulated by thrombin
(a strong physiological agonist), and platelet aggregation induced by adenosine diphosphate (a strong physiological stimulator).
We have observed that carnitine decreases platelet activation (measured by platelet aggregation, the generation of O2 - · {\hbox{O}}_2^{ - \bullet } , and TBARS production). Moreover, our results in vitro demonstrate that carnitine may protect against oxidation of thiol
groups induced by ONOO−. Thus, carnitine may have some protectory effects against oxidative changes induced in blood platelets. 相似文献
12.
Deutch CE 《Antonie van Leeuwenhoek》2011,99(4):781-793
Staphylococcus saprophyticus strains ATCC 15305, ATCC 35552, and ATCC 49907 were found to require l-proline but not l-arginine for growth in a defined culture medium. All three strains could utilize l-ornithine as a proline source and contained l-ornithine aminotransferase and Δ1-pyrroline-5-carboxylate reductase activities; strains ATCC 35552 and ATCC 49907 could use l-arginine as a proline source and had l-arginase activity. The proline requirement also could be met by l-prolinamide, l-proline methyl ester, and the dipeptides l-alanyl-l-proline and l-leucyl-l-proline. The bacteria exhibited l-proline degradative activity as measured by the formation of Δ1-pyrroline-5-carboxylate. The specific activity of proline degradation was not affected by addition of l-proline or NaCl but was highest in strain ATCC 49907 after growth in Mueller–Hinton broth. A membrane fraction from this
strain had l-proline dehydrogenase activity as detected both by reaction of Δ1-pyrroline-5-carboxylate with 2-aminobenzaldehyde (0.79 nmol min−1 mg−1) and by the proline-dependent reduction of p-iodonitrotetrazolium (20.1 nmol min−1 mg−1). A soluble fraction from this strain had Δ1-pyrroline-5-carboxylate dehydrogenase activity (88.8 nmol min−1 mg−1) as determined by the NAD+-dependent oxidation of dl-Δ1-pyrroline-5-carboxylate. Addition of l-proline to several culture media did not increase the growth rate or final yield of bacteria but did stimulate growth during
osmotic stress. When grown with l-ornithine as the proline source, S. saprophyticus was most susceptible to the proline analogues L-azetidine-2-carboylate, 3,4-dehydro-dl-proline, dl-thiazolidine-2-carboxylate, and l-thiazolidine-4-carboxylate. These results indicate that proline uptake and metabolism may be a potential target of antimicrobial
therapy for this organism. 相似文献
13.
M. Helanto K. Kiviharju T. Granström M. Leisola A. Nyyssölä 《Applied microbiology and biotechnology》2009,83(1):77-83
l-Ribose is a rare and expensive sugar that can be used as a precursor for the production of l-nucleoside analogues, which are used as antiviral drugs. In this work, we describe a novel way of producing l-ribose from the readily available raw material l-arabinose. This was achieved by introducing l-ribose isomerase activity into l-ribulokinase-deficient Escherichia coli UP1110 and Lactobacillus plantarum BPT197 strains. The process for l-ribose production by resting cells was investigated. The initial l-ribose production rates at 39°C and pH 8 were 0.46 ± 0.01 g g−1 h−1 (1.84 ± 0.03 g l−1 h−1) and 0.27 ± 0.01 g g−1 h−1 (1.91 ± 0.1 g l−1 h−1) for E. coli and for L. plantarum, respectively. Conversions were around 20% at their highest in the experiments. Also partially purified protein precipitates
having both l-arabinose isomerase and l-ribose isomerase activity were successfully used for converting l-arabinose to l-ribose. 相似文献
14.
Y. W. Kim R. Newton J. Frampton K.-H. Han 《In vitro cellular & developmental biology. Plant》2009,45(4):400-406
Embryogenic suspensor mass (ESM) was established from immature seeds of Fraser fir. The initiation frequency of ESM was dependent
on genotype, collection time, medium, and plant growth regulators (PGR) used. The ESM initiation potential was higher with
seeds collected in late June (clone 16-273, 4.7%) or early July (clone 16-45, 2.2%) and decreased as the zygotic embryos matured.
Excised proembryo stage of zygotic embryos was most appropriate to initiation of ESM. Most of the ESM arose from the seeds
that were at the proembryo stage. From the four different culture media we compared, seven ESM lines were obtained: two lines
from Murashige and Skoog (MS) medium with 4.4 μM benzyladenine (BA), one from Schenk and Hildebrandt (SH) medium with 4.5 μM
thidiazuron (TDZ), and four from SH with 4.4 μM 6-benzyladenine. However, only one ESM line from clone 16-273 (June 24, SH+TDZ)
could be proliferated in subsequent culture. Different concentrations of l-glutamine and casein hydrolysate (CH) in the medium were also compared for their effect on ESM proliferation. The highest
proliferation rate (1.16-fold) was obtained from SH medium supplemented with 250 mg/L CH and 3.42 mM l-glutamine. In contrast, the lowest rate was noted when 1,000 mg/L CH plus 3.42 mM l-glutamine (0.17-fold) was added to the medium. As for somatic embryo maturation, the highest number of mature precotyledonary
(100.1/g−1 FW ESM) or cotyledonary (64.3/g−1 FW ESM) somatic embryos was obtained on a medium containing 20 or 80 μM abscisic acid, 10% polyethyleneglycol, 4% maltose,
and 0.3% gellan gum. For germination of the somatic embryos, the cotyledonary somatic embryos derived from maturation medium
were transferred on half-strength Litvay medium containing 0.3% gellan gum. The somatic plantlets were recovered from the
germination medium and transferred to soils. 相似文献
15.
Increased Lipid Peroxidation and Ascorbic Acid Utilization in Testis and Epididymis of Rats Chronically Exposed to Lead 总被引:4,自引:0,他引:4
Mariola Marchlewicz Barbara Wiszniewska Bolesław Gonet Irena Baranowska-Bosiacka Krzysztof Safranow Agnieszka Kolasa Wojciech Głąbowski Rafał Kurzawa Katarzyna Jakubowska Monika E. Rać 《Biometals》2007,20(1):13-19
The hypothesis has been recently presented that lead may exert its negative effect at least partially through the increase
of reactive oxygen species (ROS) level in tissues. However, little is known about the influence of lead intoxication on equilibrium
between generation and elimination of ROS in the male reproductive system. Sexually mature male Wistar rats were given ad libitum 1% of aqueous solution of lead acetate (PbAc) for 9 months. Significantly higher lead concentrations were found in blood
[median 7.03 (Q25–Q75: 2.99–7.65) versus 0.18 (0.12–0.99) μg dl−1, P < 0.01], caput epididymis [median 5.51 (Q25–Q75: 4.31–7.83) versus 0.51 (0.11–0.80) μg g−1 d.m., P < 0.001], cauda epididymis [median 5.88 (Q25–Q75: 4.06–8.37) versus 0.61 (0.2 – 1.08) μg g−1 d.m., P < 0.001] and testis [median 1.81 (Q25–Q75: 0.94–2.31) versus 0.17 (0.03–0.3) μg g−1 d.m., P < 0.01] of lead-intoxicated rats when compared to the control. The concentration of ascorbyl radical, generated in vitro from l-ascorbic acid (present in tissues in vivo) was measured by means of Electron Paramagnetic Resonance (EPR) spectroscopy. The EPR signal of ascorbyl radical in caput
epididymis, cauda epididymis, testis and liver of lead acetate-treated animals revealed a significant decrease by 53%, 45%,
40% and 69% versus control tissues, respectively. Plasma l-ascorbic acid content measured by high performance liquid chromatography (HPLC) method and total antioxidant status (TAS)
measured by means of spectrophotometry were also significantly lower in the intoxicated versus control animals (28% and 21%, respectively). In the group exposed to lead the concentration of lipid peroxide in homogenates
of the reproductive system organs was significantly elevated versus control group. It can be assumed that the lower EPR signal was caused by decreased tissue concentrations of l-ascorbic acid. The latter may have resulted from consumption of ascorbic acid for scavenging of ROS excess in tissues of
animals chronically exposed to lead. 相似文献
16.
Selvatici R Previati M Marino S Marani L Falzarano S Lanzoni I Siniscalchi A 《Neurochemical research》2009,34(5):909-916
The features of neuronal damage induced by the mitochondrial toxin NaN3 were investigated in rat primary cortical neuron cultures. Cell viability (MTT colorimetric determination) and transmembrane
mitochondrial potential (J-C1 fluorescence) were concentration-dependently reduced 24 h after NaN3; neither nuclear fragmentation by DAPI, nor Annexin V positivity by flow cytometry were detected, ruling out the occurrence
of apoptosis. The loss in cell viability (to 54 ± 2%) observed 24 h after a 10-min treatment with 3 mM NaN3 was prevented by the NMDA glutamate receptor antagonist MK801 (1 μM), by the antioxidants trolox (100 μM) and acetyl-l-carnitine (1 mM) and by the nitric oxide synthase inhibitor, L-NAME (100 μM), but not by the guanylylcyclase inhibitor ODQ,
10 μM. The mitochondrial dysfunction induced by NaN3 provides a common platform for investigating the mechanisms of both ischemic and degenerative neuronal injury, useful for
screening potential protective agents against neuronal death.
Rita Selvatici and Maurizio Previati equally contributed to the work. 相似文献
17.
Yang Guo Qiaojuan Yan Zhengqiang Jiang Chao Teng Xinlei Wang 《Journal of industrial microbiology & biotechnology》2010,37(11):1137-1143
The aim of this study is to investigate production of l-lactic acid from sucrose and corncob hydrolysate by the newly isolated R. oryzae GY18. R. oryzae GY18 was capable of utilizing sucrose as a sole source, producing 97.5 g l−1
l-lactic acid from 120 g l−1 sucrose. In addition, the strain was also efficiently able to utilize glucose and/or xylose to produce high yields of l-lactic acid. It was capable of producing up to 115 and 54.2 g l−1 lactic acid with yields of up to 0.81 g g−1 glucose and 0.90 g g−1 xylose, respectively. Corncob hydrolysates obtained by dilute acid hydrolysis and enzymatic hydrolysis of the cellulose-enriched
residue were used for lactic acid production by R. oryzae GY18. A yield of 355 g lactic acid per kg corncobs was obtained after 72 h incubation. Therefore, sucrose and corncobs could
serve as potential sources of raw materials for efficient production of lactic acid by R. oryzae GY18. 相似文献
18.
Takashi Nemoto Taisuke Watanabe Yutaka Mizogami Jun-ichi Maruyama Katsuhiko Kitamoto 《Applied microbiology and biotechnology》2009,82(6):1105-1114
The recombinant Pichia pastoris harboring an improved methionine adenosyltransferase (MAT) shuffled gene was employed to biosynthesize S-adenosyl-l-methionine (SAM). Two l-methionine (l-Met) addition strategies were used to supply the precursor: the batch addition strategy (l-Met was added separately at three time points) and the continuous feeding strategies (l-Met was fed continuously at the rate of 0.1, 0.2, and 0.5 g l−1 h−1, respectively). SAM accumulation, l-Met conversion rate, and SAM productivity with the continuous feeding strategies were all improved over the batch addition
strategy, which reached 8.46 ± 0.31 g l−1, 41.7 ± 1.4%, and 0.18 ± 0.01 g l−1 h−1 with the best continuous feeding strategy (0.2 g l−1 h−1), respectively. The bottleneck for SAM production with the low l-Met feeding rate (0.1 g L−1 h−1) was the insufficient l-Met supply. The analysis of the key enzyme activities indicated that the tricarboxylic acid cycle and glycolytic pathway
were reduced with the increasing l-Met feeding rate, which decreased the adenosine triphosphate (ATP) synthesis. The MAT activity also decreased as the l-Met feeding rate rose. The reduced ATP synthesis and MAT activity were probably the reason for the low SAM accumulation when
the l-Met feeding rate reached 0.5 g l−1 h−1. 相似文献
19.
Kim YS Lee JH Kim NH Yeom SJ Kim SW Oh DK 《Applied microbiology and biotechnology》2011,90(2):489-497
In the fed-batch culture of glycerol using a metabolically engineered strain of Escherichia coli, supplementation with glucose as an auxiliary carbon source increased lycopene production due to a significant increase in
cell mass, despite a reduction in specific lycopene content. l-Arabinose supplementation increased lycopene production due to increases in cell mass and specific lycopene content. Supplementation
with both glucose and l-arabinose increased lycopene production significantly due to the synergistic effect of the two sugars. Cell growth by the
consumption of carbon sources was related to endogenous metabolism in the host E. coli. Supplementation with l-arabinose stimulated only the mevalonate pathway for lycopene biosynthesis and supplementation with both glucose and l-arabinose stimulated synergistically only the mevalonate pathway. In the fed-batch culture of glycerol with 10 g l−1 glucose and 7.5 g l−1
l-arabinose, the cell mass, lycopene concentration, specific lycopene content, and lycopene productivity after 34 h were 42 g l−1, 1,350 mg l−1, 32 mg g cells−1, and 40 mg l−1 h−1, respectively. These values were 3.9-, 7.1-, 1.9-, and 11.7-fold higher than those without the auxiliary carbon sources,
respectively. This is the highest reported concentration and productivity of lycopene. 相似文献
20.
α‐Lipoic acid inhibits testicular and epididymal oxidative damage and improves fertility efficacy in arsenic‐intoxicated rats
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Papisetty Prathima Ramanadhapuram Pavani Sadepalli Sukeerthi Sri Bhashyam Sainath 《Journal of biochemical and molecular toxicology》2018,32(2)
The present study evaluates the protective effect of α‐lipoic acid (LA) against arsenic‐induced testicular and epididymal oxidative damage in rats. Arsenic caused significant reduction in the reproductive organ weights, serum testosterone levels, testicular daily sperm count, epididymal sperm count, sperm motility, sperm viability, and sperm membrane integrity. Significant reduction in the activity levels of superoxide dismutase, catalase, and glutathione levels with a concomitant increase in the lipid peroxidation and protein carbonyl content in the testis and the cauda epididymis of arsenic‐exposed rats. Arsenic intoxication also enhanced the testicular caspase‐3 mRNA levels, disorganization of testicular and cauda epididymal architecture as well as increased arsenic content in the testis and the cauda epididymis of rats. Arsenic exposure also deteriorated fertility ability in male rats over controls. Conversely, α‐LA negated the testicular and cauda epididymal oxidative stress and restored the male reproductive health in arsenic‐exposed rats. 相似文献