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Halomonas can grow on diverse carbon sources. As it can be used for unsterile fermentation under high-salt conditions, it has been applied as a chassis for next-generation industrial biotechnology. Short-chain volatile fatty acids, including acetate, propionate, and butyrate, can be prepared from biomass and are expected to be novel carbon sources for microbial fermentation. Halomonas sp. TD01 and TD08 were subjected to shaking culture with 10-50 g/L butyrate, and they were found to effectively synthesize poly-3-hydroxybutyrate with butyrate as the carbon source. The highest yield of poly-3-hydroxybutyrate was achieved at butyrate concentration of 20 g/L (9.12 g/L and 7.37 g/L, respectively). Butyrate at the concentration > 20 g/L inhibited cell growth, and the yield of poly-3-hydroxybutyrate decreased to < 4 g/L when butyrate concentration was 50 g/L. Moreover, Halomonas sp. TD08 can accumulate the copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate by using propionate and butyrate as carbon sources. However, propionate was toxic to cells. To be specific, when 2 g/L propionate and 20 g/L butyrate were simultaneously provided, cell dry weight and polymer titer were 0.83 g/L and 0.15 g/L, respectively. The addition of glycerol significantly improved cell growth and boosted the copolymer titer to 3.95 g/L, with 3-hydroxyvalerate monomer content of 8.76 mol%. Short-chain volatile fatty acids would be promising carbon sources for the production of polyhydroxyalkanoates by Halomonas.
Subject(s)
Butyrates , Carbon , Fatty Acids, Volatile , Halomonas , Polyhydroxyalkanoates , PropionatesABSTRACT
The marine genus Marinobacterium was first identified in 1997, and a total of 18 species have been characterized so far, 10 of which have published whole-genome sequencing data. This article summarizes the characteristics of Marinobacterium genus and analyzes the genome sequencing data related to the carbon source utilization, polyhydroxyalkanoate metabolism, and aromatic compounds degradation. The Marinobacterium species possess the complete glycolysis pathway and tricarboxylic acid cycle, yet lack genes involved in xylose utilization. All strains of the Marinobacterium genus contain the genes encoding for the typeⅠand type Ⅲ polyhydroxyalkanoate synthases, suggesting that the genus may have ability of polyhydroxyalkanoate accumulation. The Marinobacterium species contain the degradation pathways of aromatic compounds. Benzene, phenol and benzoic acid can be degraded into catechol via different enzymes, subsequently catechol is converted to 3-ketoadipate through the ortho-cleavage pathway. Alternatively, catechol can be degraded into pyruvate and acetyl-CoA. The analysis of genome sequencing data of the Marinobacterium genus provides in-depth understanding of the metabolic characteristics, indicating that the genus may have certain applications in the synthesis of polyhydroxyalkanoate and the removal of marine aromatic compounds.
Subject(s)
Alteromonadaceae , DNA, Bacterial , Phylogeny , RNA, Ribosomal, 16S , Sequence Analysis, DNAABSTRACT
Escherichia coli was metabolically engineered to produce poly(glycolate-co-lactate-co-3-hydroxybutyrate) using glucose and xylose as carbon sources. The combinatorial biosynthetic route was constructed by the overexpression of a series of enzymes including D-tagatose 3-epimerase, L-fuculokinase, L-fuculose-phosphate aldolase, aldehyde dehydrogenase, propionyl-CoA transferase, β-ketothiolase, acetoacetyl-CoA reductase, and polyhydroxyalkanoate synthase. Overexpression of polyhydroxyalkanoate granule associated protein significantly improved biopolymer synthesis, and the recombinant strain reached 3.73 g/L cell dry weight with 38.72% (W/W) biopolymer content. A co-culture engineering strategy was developed to produce biopolymer from a mixture of glucose and xylose, achieving 4.01 g/L cell dry weight containing 21.54% (W/W) biopolymer. The results of this work offer an approach for simultaneously utilizing glucose and xylose and indicate the potential for future biopolymer production from lignocellulosic biomass.
Subject(s)
3-Hydroxybutyric Acid , Escherichia coli , Glucose , Glycolates , Lactates , Metabolic Engineering , Polyesters , XyloseABSTRACT
The effects of prescriptions of fragrant traditional Chinese medicine covered in ancient books on traditional Chinese medicine published in the past dynasties on disease control and treatment were retrieved from the Full-text Database of Ancient Books on Traditional Chinese Medicine developed by Nanjing University of Traditional Chinese Medicine. A fragrant medicinal subject system with unique characteristics was established by analyzing the characteristics of prescribed fragrant traditional Chi-nese medicine and the prescribing rules of fragrant traditional Chinese medicine according to theirprinciples-methods-formulae-medicinal, clarifying the related factors influencing diseases and the related mechanisms of prescriptions, which can not only promote the theoretical and practical development of external treatment with prescriptions of fragrant traditional Chinese medicine but also provide the reliable philological basis for external diseases and pharmacology of traditional Chinese medical formulae.
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Objective To evaluate the diagnostic and therapeutic value and safety of transcatheter arterial angiography and embolization in patients with endoscopic refractory gastrointestinal bleeding.Methods Thirty-one cases of endoscopic refractory gastrointestinal bleeding were performed DSA and treated with transcatheter arterial angiography and embolization.The safty and efficacy was evaluated.Results Angiographic positive rate of bleeding was 80.65％ (25/31);28 cases was treated with embolization.The success rate of first embolization was 75.00％ (21/28),and the total success rate was 82.14 ％ (23/28) by the second embolization.Seven patients received surgical resection after interventional therapy,including 2 cases of jejunal stromal tumors and 5 cases of gastric malignant tumors.Four cases of gastric cancer patients underwent rebleeding within 30 days after interventional therapy,of which 2 died of heart or lung function failure due to basic diseases.Except for 1 patient of anastomotic bleeding after gastrointestinal anastomosis occurred anastomotic fistula after embolization,who recovery with the support treatment,no other cases occurred serious gastrointestinal ischemic necrosis.Conclusion Interventional diagnosis and treatment for gastrointestinal bleeding hemostasis is effective and safety,and also can achieve good results especially for malignant gastric tumor hemorrhage,which can be used for endoscopic refractory gastrointestinal bleeding patients.
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Objective To investigate altered microstructural integrity in acute carbon monoxide(CO)intoxication by diffusion tensor imaging (DTI).Methods A total of 25 CO intoxication patients (5.0±1.44 post-intoxication)and 37 healthy volunteers matched with age, sex and educational level were involved and underwent DTI.The fractional anisotropy (FA)and apparent diffusion confficient (ADC) of total 26 regions of bilateral cerebellum,substantia nigra,hippocampus,white matter of frontal lobe,head of caudate nucleus,pallidum,thalamus, anterior limb of internal capsule,posterior limb of internal capsule,white matter of occipital lobe,white matter of parietal lobe,and genu of corpus callosum,splenium of corpus callosum were measured.Compared the patients against control for FA and ADC by paired t-test.Results FA of patients with CO intoxication decreased in bilateral pallidum,anterior limb of internal capsule,substantia nigra,right cerebellum,left below frontal white matter,right frontal white matter and genu of corpus callosum (P <0.05).ADC decreased in right substantia nigra,and left pallidum (P <0.05).ADC increased in right frontal white matter and bilateral occipital lobe white matter (P<0.05).Conclusion There is loss of microstructural integrity in acute CO intoxication,perhaps representing the underlying mechanism of delayed encephalopathy after carbon monoxide poisoning.
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Objective To analyze CT morphologic features and pathologic changes of pulmonary sclerosing pneumocytoma (PSP) and to improve preoperative diagnostic accuracy of PSP.Methods The clinical and CT data of 12 cases with PSP (with total 13 lesions)confirmed by surgery and pathology were collected and analyzed retrospectively.All cases performed CT plain scan,9 cases had contrast CT scan.Results 1 1 cases had isolated lesions,and 1 case multiple lesions.The long-axis diameter ranged from 1.10 cm to 8.03 cm, with an average of (3.53±0.78)cm.Of 13 lesions,3 located in left lung (23.1%,1 in the upper lobes,2 in lower lobe),and 10 in right lung (76.9%,2 in upper lobe,2 in the middle lobe and 6 in lower lobe);8 lesions located in the lower lobe (61.5%),and 5 in upper and middle lobe (38.5%).There were center type of 4 lesions (30.8%),and peripheral type of 9 lesions (69.2%);The shapes of 8 lesions wereovoid or similar round (61.5%),irregular type of 1 case (7.7%),shallow lobe of 4 cases (30.8%);Smooth edge of 10 cases (76.9%), burr edge in 3 cases (23.1%).With contrast CT scan,7 cases (53.8%)had vascular welt sign,6 cases (46.2%)had air crescent sign,6 cases (46.2%)had halo sign,and 6 cases (46.2%)had tail sign.3 lesions (23.1%)had scattered spot calcification,and the other lesions had uniform density.The CT value ranged from 28 HU to 47 HU,with the average of 35 HU;Of 9 cases (with 10 lesions)with contrast CT scan,2 lesions had mild enhancement,5 cases had obvious enhancement,and 3 case had non-uniform enhancement.Enhanced CT value was 60-1 10 HU,with the average of 77.2 HU,and with the maximum of 75 HU.Conclusion If the pulmonary nodules or masses in middle-aged females had single round or ovoid shape,with about 3 cm diameters,soft-tissue density,smooth edge,and with obvious enhancement after contrast CT scan,and accompanied by vascular welt sign,air crescent sign,halo sign,or tail sign, the diagnosis of PSP should be considered.
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<p><b>OBJECTIVE</b>To compare the toxicity on normal liver cells LO2 before and after Kansui Radix stir-baked with vinegar, and make a preliminary study on the mechanism of detoxication of Kansui Radix stir-baked with vinegar.</p><p><b>METHOD</b>The MTT method was adopted to detect the cell activity, with normal liver cells LO2 as the study object. The morphology of cells were observed, and the level or content of AST, ALT, LDH, SOD, Na+-K+-ATPase, Ca2+-Mg2+ -ATPase, GSH and MDA were determined in cell culture supernatant and splitting supernatant.</p><p><b>RESULT</b>Compared with the control group, Kansui can obviously inhibit the cell activity (P < 0.01) and morphology, and increase the levels of ALT, AST, and LDH (P < 0.01) in the supernatant fluid of cell incubation, and decrease the level of SOD and the content of GSH (P < 0.01). Besides, it significantly increased the content of MDA (P < 0.01) and significantly decreased the level of Na+-K+-ATPase and Ca2+-Mg2+ -ATPase (P < 0.01) in the supernatant fluid of cell dissociation. Compared with Kansui group of various doses, Kansui Radix stir-baked with vinegar can significantly decrease the cell proliferation inhibition and the trend of morphological variation, and obviously decrease the levels of ALT, AST, and LDH (P < 0.01) in the supernatant fluid of cell incubation, and significantly increase the level of SOD and the content of GSH (P < 0.01), and significantly decrease the content of MDA (P < 0.01). Additionally, it significantly increased the level of Na+-K+-ATPase and Ca2+-Mg2+ ATPase (P < 0.01) in the supernatant fluid of cell dissociation, and showed a certain dose-effect relationship.</p><p><b>CONCLUSION</b>Stir-baking with rice vinegar can release the hepatotoxicity of Kansui Radix. Its possible mechanism was that Kansui Radix stir-baked with vinegar can decrease the influence of Kansui Radix on the permeability of liver cells LO2 membrane and oxidative damage, in order to provide basis for further exploration of the detoxication mechanism of Kansui Radix stir-baked with vinegar.</p>
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Humans , Acetic Acid , Chemistry , Cell Line , Cell Proliferation , Chemistry, Pharmaceutical , Drugs, Chinese Herbal , Chemistry , Toxicity , Euphorbia , Chemistry , Liver , Cell Biology , Oxidative Stress , Plant Roots , Chemistry , Sodium-Potassium-Exchanging ATPase , MetabolismABSTRACT
Polyhydroxyalkanoates (PHA) are diverse polyesters synthesized by a variety of bacteria as intracellular carbon and energy storage compounds. As bio-renewable and biodegradable materials with diverse properties, PHA have drawn industrial attentions for their potential applications in many fields. This review focuses on recent strain developments for PHA production via cofactor engineering and metabolic engineering. The microaerobic production of PHA and application of PHA synthesis genes for improving robustness of industrial microorganisms are addressed.
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Bacteria , Metabolism , Genetic Engineering , Industrial Microbiology , Metabolic Networks and Pathways , Polyhydroxyalkanoates , Chemistry , GeneticsABSTRACT
Nano-fumed silica derivative with quaternary ammonium group was synthesized and the antimicrobial activity was investigated. The nano-fumed silica derivative was investigated by Fourier-transform infrared spectroscopy (FTIR). The zeta potential and the size of the nano-fumed silica derivative were measured. The antimicrobial properties of the nano-fumed silica derivative against selected microorganisms were tested by the quantitative suspension method. The zeta potential showed that the isoelectric points of nano-fumed silica and modified nano-fumed silica are pH=4. 8 and pH =10.5-10.8, respectively, and the shift of the isoelectric point is due to the quaternary ammonium salt. The obtained nano-fumed silica derivative inhibited the growth of Gram-negative (Escherichia coli), Gram-positive bacteria (Staphylococcus aureus), and fungus (Candida albicans). The inhibiting effect of nano-fumed silica derivative on the microorganisms varied with the time of exposure. The bacteriostatic rates were noted to be 99.99%, 99.99% and 94.12% after 15 minutes' exposure, respectively. Thus the results indicate that nano-fumed silica derivative with quaternary ammonium group has significant inhibitory effect on the growth of bacteria.
Subject(s)
Anti-Infective Agents , Pharmacology , Escherichia coli , Fungi , Nanotechnology , Quaternary Ammonium Compounds , Chemistry , Silicon Dioxide , Chemistry , Spectroscopy, Fourier Transform Infrared , Staphylococcus aureus , Surface PropertiesABSTRACT
The ethical education of laboratory medicine,as the indispensable part of modern medicine practice,hasn't been adequately emphasized,so that non-ethical things often ouur.This artide discusses the importance of ethical education on the field of laboratry medicine.