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1.
Mar Biotechnol (NY) ; 20(6): 803-812, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30218327

RESUMEN

In recent years, some marine microbes have been used to degrade diesel oil. However, the exact mechanisms underlying the biodegradation are still poorly understood. In this study, a hypothermophilous marine strain, which can degrade diesel oil in cold seawater was isolated from Antarctic floe-ice and identified and named as Rhodococcus sp. LH. To clarify the biodegradation mechanisms, a gas chromatography-mass spectrometry (GC-MS)-based metabolomics strategy was performed to determine the diesel biodegradation process-associated intracellular biochemical changes in Rhodococcus sp. LH cells. With the aid of partial least squares-discriminant analysis (PLS-DA), 17 differential metabolites with variable importance in the projection (VIP) value greater than 1 were identified. Results indicated that the biodegradation of diesel oil by Rhodococcus sp. LH was affected by many different factors. Rhodococcus sp. LH could degrade diesel oil through terminal or sub-terminal oxidation reactions, and might also possess the ability to degrade aromatic hydrocarbons. In addition, some surfactants, especially fatty acids, which were secreted by Rhodococcus into medium could also assist the strain in dispersing and absorbing diesel oil. Lack of nitrogen in the seawater would lead to nitrogen starvation, thereby restraining the amino acid circulation in Rhodococcus sp. LH. Moreover, nitrogen starvation could also promote the conversation of relative excess carbon source to storage materials, such as 1-monolinoleoylglycerol. These results would provide a comprehensive understanding about the complex mechanisms of diesel oil biodegradation by Rhodococcus sp. LH at the systematic level.


Asunto(s)
Biodegradación Ambiental , Gasolina , Hidrocarburos/metabolismo , Rhodococcus/metabolismo , Regiones Antárticas , Metaboloma , Nitrógeno , Rhodococcus/química , Agua de Mar/química , Tensoactivos , Contaminantes Químicos del Agua/metabolismo
2.
Curr Microbiol ; 74(8): 921-929, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28516199

RESUMEN

Calmodulin (CaM) is a Ca2+-binding protein that plays a role in several Ca2+ signaling pathways, which dynamically regulates the activities of hundreds of proteins. The ice alga Chlamydomonas sp. ICE-L, which has the ability to adapt to extreme polar conditions, is a crucial primary producer in Antarctic ecosystem. This study hypothesized that Cam helps the ICE-L to adapt to the fluctuating conditions in the polar environment. It first verified the overall length of Cam, through RT-PCR and RACE-PCR, based on partial Cam transcriptome library of ICE-L. Then, the nucleotide and predicted amino acid sequences were, respectively, analyzed by various bioinformatics approaches to gain more insights into the computed physicochemical properties of the CaM. Potential involvements of Cam in responding to certain stimuli (i.e., UVB radiation, high salinity, and temperature) were investigated by differential expression, measuring its transcription levels by means of quantitative RT-PCR. Results showed that CaM was indeed inducible and regulated by high UVB radiation, high salinity, and nonoptimal temperature conditions. Different conditions had different expression tendencies, which provided an important basis for investigating the adaptation mechanism of Cam in ICE-L.


Asunto(s)
Calmodulina/análisis , Calmodulina/genética , Chlamydomonas/enzimología , Perfilación de la Expresión Génica , Regiones Antárticas , Calmodulina/química , Chlamydomonas/efectos de los fármacos , Chlamydomonas/genética , Chlamydomonas/efectos de la radiación , Clonación Molecular , Biología Computacional , Presión Osmótica , Reacción en Cadena de la Polimerasa , Salinidad , Temperatura , Rayos Ultravioleta
3.
Mar Pollut Bull ; 120(1-2): 184-191, 2017 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-28511941

RESUMEN

Ocean acidification (OA) resulting from increasing atmospheric CO2 strongly influences marine ecosystems, particularly in the polar ocean due to greater CO2 solubility. Here, we grew the Antarctic sea ice diatom Nitzschia sp. ICE-H in a semicontinuous culture under low (~400ppm) and high (1000ppm) CO2 levels. Elevated CO2 resulted in a stimulated physiological response including increased growth rates, chlorophyll a contents, and nitrogen and phosphorus uptake rates. Furthermore, high CO2 enhanced cellular particulate organic carbon production rates, indicating a greater shift from inorganic to organic carbon. However, the cultures grown in high CO2 conditions exhibited a decrease in both extracellular and intracellular carbonic anhydrase activity, suggesting that the carbon concentrating mechanisms of Nitzschia sp. ICE-H may be suppressed by elevated CO2. Our results revealed that OA would be beneficial to the survival of this sea ice diatom strain, with broad implications for global carbon cycles in the future ocean.


Asunto(s)
Carbono , Clorofila/análisis , Diatomeas , Cubierta de Hielo , Regiones Antárticas , Dióxido de Carbono , Clorofila A , Océanos y Mares
4.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 21(1): 150-4, 2013 Feb.
Artículo en Chino | MEDLINE | ID: mdl-23484710

RESUMEN

This study was aimed to investigate the radioprotective effects of recombinant human interleukin-12 (rhIL-12) on monkey hematopoietic system, and to provide experimental evidence for future clinical prophylaxis and treatment for patients who suffered from acute radiation syndrome. In in vitro study, the effect of rhIL-12 in different concentrations (0, 1, 5, 25, 125 and 625 ng/ml) on colony forming capacity of human or monkey bone marrow-derived mononuclear cells was examined in methylcellulose H4434 medium. In in vivo study, the acute radiation syndrome model was established in 11 Rhesus monkeys which received lethal total body irradiation by 6 Gy (60)Co γ in single time irradiation. The irradiated monkeys were randomly divided into 3 subgroups: control group (n = 4) which received subcutaneous PBS injection, rhIL-12 single-dose group (n = 3) which received subcutaneous single injection of rhIL-12 (4 µg/kg) at 2 h after irradiation, and multiple-dose group (n = 4) which received subcutaneous injection of rhIL-12 (1 µg/kg per injection) at 2 h, day 3, 6 and 9 after irradiation respectively. Peripheral blood cells were counted before and after irradiation every other day. The survival status of animals were observed daily. In vitro test results showed that different concentrations of rhIL-12 obviously promoted human and healthy monkeys' bone marrow mononuclear cells to form various hematopoietic progenitor cell colonies, especial CFU-E and CFU-GM. All animals in control group died within 22 d after lethal total body irradiation, average survival time was (20.3 ± 1.2) d. Only one monkey in multiple-dose group died due to anemia on day 17. All monkeys in single-dose group survived. Compared with control group, rhIL-12-administrated monkeys' white blood cell count, hemoglobin level, platelet and reticulocyte counts showed faster recovery from high dose radiation. It is concluded that the rhIL-12 treatment can promote the bone marrow hematopoietic stem/progenitor cell colony formation in vitro and protect lethally-irradiated monkeys. There is an obvious therapeutic effect of rhIL-12 on monkeys suffered from bone marrow failure caused by severe acute radiation exposure.


Asunto(s)
Células Madre Hematopoyéticas/efectos de los fármacos , Interleucina-12/farmacología , Protectores contra Radiación/farmacología , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/efectos de la radiación , Células Cultivadas , Células Madre Hematopoyéticas/efectos de la radiación , Humanos , Macaca mulatta , Proteínas Recombinantes de Fusión/farmacología
5.
Mar Genomics ; 5: 59-64, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22325723

RESUMEN

A cDNA (GenBank ID: GU395492) encoding cytosolic glutathione reductase (named ICE-LGR) in Antarctic microalgae Chlamydomonas sp. ICE-L was successfully cloned by RT-PCR and rapid amplification of cDNA ends technique (RACE). The expression patterns of ICE-LGR under different salinity stresses were determined by real-time PCR. ICE-LGR cDNA has 1913 bp nucleotides with an open reading frame (ORF) of 1458 bp, encoding 485 amino acid residues. The deduced amino acid sequence shows 79% homology with glutathione reductase (GR) of Chlamydomonas reinhardtii. Activity assessment and mRNA expression analysis results showed that activity and expression level of GR in ICE-L cells were up-regulated under either high or low salinity. Together, our results revealed that ICE-LGR might play an important role in Antarctic ice algae Chlamydomonas sp. ICE-L acclimatizing to polar high salinity environment as well as low salinity. These results provide us valuable information on further investigating the molecular mechanism of ICE-LGR.


Asunto(s)
Chlamydomonas/genética , Glutatión Reductasa/metabolismo , Proteínas de Plantas/metabolismo , Secuencia de Aminoácidos , Regiones Antárticas , Chlamydomonas/enzimología , Clonación Molecular , Regulación de la Expresión Génica de las Plantas , Glutatión Reductasa/genética , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Filogenia , Proteínas de Plantas/genética , ARN de Planta/genética , Salinidad , Alineación de Secuencia , Estrés Fisiológico
6.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(2): 418-21, 2011 Feb.
Artículo en Chino | MEDLINE | ID: mdl-21510394

RESUMEN

Laser tweezers Raman spectroscopy can help with observing and studying individual cells or organelles in a natural state for a relatively long period. In the present experiment, Laser tweezers Raman spectroscopy (LTRS) was used as a tool to report physiological metabolism such as cells growth and nucleic acid, proteins, lipid and glucose of a single active cold-adapted Aromatic hydrocarbons-degradating strains isolated from Antarctic Sea. After the Raman spectrum was collected and analyzed, the findings are as follows: Raman spectrum identified the components of a single cold-adapted Aromatic hydrocarbons-degradating strain and there were more proteins and carbohydrate produced during the Planococcus sp. NJ41 and Shewanella sp. NJ49 growth and degradation; but there was more lipid than the proteins produced during the Pseudoalteromonas sp. NJ289 growth and degradation; the amount of proteins produced by the strains corresponds with the production of degradation rate-limiting enzyme, and was also related to the capacity of low-temperature degradation of aromatic hydrocarbons.


Asunto(s)
Bacterias/metabolismo , Hidrocarburos Aromáticos/metabolismo , Espectrometría Raman/métodos , Regiones Antárticas , Pinzas Ópticas , Microbiología del Agua
7.
Biotechnol Lett ; 28(2): 85-8, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16369690

RESUMEN

Marinomonas sp. NJ522, isolated from Antarctic sea ice, produces a cold-active iron superoxide dismutase (SOD; EC 1.15.1.1). The purified SOD was dimeric and had an approx. Mr of 48 kDa. Highest activity was detected from pH 8 to 10 and at 40 degrees C (assayed over 10 min). Activity at 0 degree C was nearly 35% of the maximum activity.


Asunto(s)
Proteínas Bacterianas/aislamiento & purificación , Bacterias Gramnegativas/enzimología , Superóxido Dismutasa/aislamiento & purificación , Proteínas Bacterianas/química , Frío , Calor , Concentración de Iones de Hidrógeno , Superóxido Dismutasa/química
8.
J Environ Sci (China) ; 18(6): 1152-6, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17294957

RESUMEN

The effect of hexadecyltrimethyleamine bromide (HDTMAB) on the removal of Alexandrium sp. LC3 under cupric glutamate stress was investigated. Toxic effect of cupric glutamate on A lexandrium sp. LC3 was significantly promoted in the presence of HDTMAB, especially at 3.0 cmc of HDTMAB. It was found that the sulfhydryl group content of the cell decreased, while the malonaldehyde content and membrane permeability increased when Alexandrium sp. LC3 was treated with HDTMAB and cupric glutamate complex, compared with cupric glutamate alone. The data suggest that HDTMAB might stimulate the damage of Alexandrium sp. LC3 by enhancing the membrane permeability.


Asunto(s)
Cobre/toxicidad , Dinoflagelados/efectos de los fármacos , Dinoflagelados/metabolismo , Glutamatos/toxicidad , Tensoactivos/toxicidad , Animales , Permeabilidad de la Membrana Celular/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Compuestos de Sulfhidrilo/metabolismo
9.
Biotechnol Lett ; 27(16): 1195-8, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16158263

RESUMEN

Colwellia sp. NJ341, isolated from Antarctic sea ice, secreted a cold-active serine protease. The purified protease had an apparent Mr of 60 kDa by SDS-PAGE and MALDI-TOF MS. It was active from pH 5-12 with maximum activity at 35 degrees C (assayed over 10 min). Activity at 0 degrees C was nearly 30% of the maximum activity. It was completely inhibited by phenylmethylsulfonyl fluoride.


Asunto(s)
Frío , Gammaproteobacteria/clasificación , Gammaproteobacteria/metabolismo , Serina Endopeptidasas/química , Serina Endopeptidasas/aislamiento & purificación , Catálisis , Activación Enzimática , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Serina Endopeptidasas/análisis , Especificidad de la Especie
10.
J Environ Sci (China) ; 17(4): 667-71, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16158602

RESUMEN

Glutathione (GSH) and GSH-related enzymes play a great role in protecting organisms from oxidative damage. The GSH level and GSH-related enzymes activities were investigated as well as the growth yield and malonyldialdehyde (MDA) content in the Antarctic ice microalga Chlamydomonas sp. ICE-L exposure to the different cadmium concentration in this paper. The results showed that the higher concentration Cd inhibited the growth of ICE-L significantly and Cd would induce formation of MDA. At the same time, it is clear that GSH level, glutathione peroxidases (GPx) activity and glutathione S-transferases (GST), activity were higher in ICE-L exposed to Cd than the control. But GR activity dropped notably when ICE-L were cultured in the medium containing Cd. Increase of GSH level, GPx and GST activities acclimate to oxidative stress induced by Cd and protect Antarctic ice microalga Chlamydomonas sp. ICE-L from toxicity caused by Cd exposure. These parameters may be used to assess the biological impact of Cd in the Antarctic pole region environment.


Asunto(s)
Cadmio/farmacología , Chlamydomonas/enzimología , Chlamydomonas/metabolismo , Glutatión Peroxidasa/metabolismo , Glutatión Transferasa/metabolismo , Glutatión/metabolismo , Hielo , Animales
11.
J Environ Sci (China) ; 17(3): 499-502, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16083134

RESUMEN

The effect of Ca2+ on the removal of Alexandrium sp. LC3 under HDTMAB stress was investigated. The results showed that the toxic effect of HDTMAB on Alexandrium sp. LC3 was significantly reduced in the presence of Ca2 , especially under 4 mmol/L of Ca2+. To understand the underlying mechanism, the SH group and MDA content of the cell membrane and membrane permeability were measured. It was found that the SH content of cell member increased, the MDA content and membrane permeability decreased when Alexandrium sp. was treated with Ca2+ and HDTMAB complex, compared with using HDTMAB only. The data suggested that Ca2+ might promote HDTMAB stress resistance of Alexandrium sp. LC3 by reducing the permeability and increasing the stability of cell membrane.


Asunto(s)
Calcio/farmacología , Permeabilidad de la Membrana Celular/efectos de los fármacos , Compuestos de Cetrimonio/toxicidad , Dinoflagelados/efectos de los fármacos , Animales , Cetrimonio , Dinoflagelados/metabolismo , Relación Dosis-Respuesta a Droga , Peroxidación de Lípido/efectos de los fármacos , Malondialdehído , Rayos Ultravioleta
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