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1.
Artigo em Inglês | MEDLINE | ID: mdl-31707053

RESUMO

Lustrin A is the first nacre protein with specific structure and amino acid residue content that was identified in abalone; since its identification, homologs have been found in several abalone species. In this study, we isolated and cloned the complete cDNA of Lustrin A from Haliotis discus hannai, which was named Hdh-Lustrin A. Hdh-Lustrin A has characteristic cysteine- and proline-rich domains, glycine- and serine-rich domains, and a whey acidic protein (WAP)-like C-terminus. The cysteine- and proline-rich domains showed internal similarity repeats that arrayed in gene coding region, and the phylogenetic tree of these repeats indicated that the similarity of structural repetitive unit components in different abalone species, reflecting their evolutionary distance. A tissue distribution analysis showed that the mRNA level of Hdh-Lustrin A has tissue-specific expression in mantle. Under lipopolysaccharide (LPS) challenge, Hdh-Lustrin A showed a significantly increase, while it showed a more complex pattern with two peaks in the process of shell regeneration. Moreover, acidification and warming raised the expression level of Hdh-Lustrin A in shell regeneration in two different manners; acidification raised the gene expression in quick response, in contrast the long run in warming treatment. Similar pattern also has been detected in immune reaction and the thermal treatments. These results suggest that the Hdh-Lustrin A is a nacre protein, which can be distinguished by its cysteine- and proline-rich domain. It involves in shell regeneration and innate immunity in abalone, and its expression pattern during shell regeneration can be disrupted by physicochemical properties of the environment.

2.
Sci Total Environ ; 711: 134551, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31812434

RESUMO

Ecological floating beds can rapidly remove nutrients (nitrogen and phosphorus) from eutrophic water, but we still know little about whether this process can simultaneously recover microbial eukaryotic communities. To fill this gap, planktonic microbial eukaryotic communities were investigated using 18S rRNA high-throughput gene sequencing during nutrient removal by floating beds of Canna indica L. We found that nutrient concentrations were high in both the control and treatment groups during period 1 (days 0-5) but rapidly decreased in the treatment group during period 2 (days 6-9) and period 3 (days 10-18). However, the microbial eukaryotic species richness and community compositions were similar between the control and treatment groups during periods 1 and 2 but showed small differences during period 3. The microbial eukaryotic co-occurrence networks between the control and treatment groups also showed similar degree centrality and interconnected eukaryotic members. We found that some abundant fungi species significantly responded to nutrient variations, but a large number of abundant ciliates were insensitive to nutrient removal. Our findings suggest that ecological floating beds can rapidly remove nutrients in eutrophic waters but that it is difficult to quickly and simultaneously improve microbial eukaryotic communities. This result reveals the critical influence of nutrient pollution on aquatic ecosystems and therefore on long-term and comprehensive aquatic habitat restoration, as aquatic macrophyte recoveries should be conducted after nutrient controls have been implemented.

3.
Mar Drugs ; 17(8)2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374944

RESUMO

Microalgae are considered as excellent candidates for bioactive compounds, yet microalgal residues remaining after the extraction of one or two compounds are usually discarded, which is not economical. This study demonstrates the alkaline extraction of proteins from Chlorella pyrenoidosa residue after lipid and pigment extractions, and their functional properties. Single-factor experiments and response surface methodology were used to obtain the optimal conditions for protein extraction. Based on our results, a maximum protein yield of 722.70 mg/g, was obtained under the following extraction conditions: sodium hydroxide concentration 7.90%, extraction temperature 70.00 °C, extraction time 34.80 min, and microalgal residue concentration 8.20 mg/mL. The molecular weight of microalgal residue protein isolate (MRPI) was mainly distributed at the regions of 0.18-0.50 kDa, 0.50-1.50 kDa, and 1.50-5.00 kDa. The essential amino acid content was greater than the values recommended by FAO/WHO standards; a high essential amino acid index value (1.49) was another good indication that MRPI is suitable for human consumption. Moreover, MRPI exhibited excellent emulsifying properties and antioxidant activity, which suggests it may be useful as an emulsifying agent and antioxidant. These findings could improve the extraction methods of functional protein from microalgal residue and add value to microalgae-based bioactive compound production processes.


Assuntos
Chlorella/química , Microalgas/química , Extratos Vegetais/farmacologia , Proteínas de Plantas/farmacologia , Sequência de Aminoácidos , Aminoácidos Essenciais/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Emulsificantes/química , Emulsificantes/isolamento & purificação , Emulsificantes/farmacologia , Alimento Funcional , Lipídeos/isolamento & purificação , Peso Molecular , Estresse Oxidativo/efeitos dos fármacos , Pigmentos Biológicos/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Hidróxido de Sódio/química , Temperatura Ambiente
4.
Bioresour Technol ; 290: 121798, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325840

RESUMO

This study isolated and identified the lutein-enriching microalga Chlorella sorokiniana FZU60. Different types of media and concentrations of sodium acetate and nitrate were evaluated to improve mixotrophic growth and lutein production. Highest lutein content, production, and productivity were obtained in BG11 medium with 1 g/L acetate and 0.75 g/L nitrate. Additionally, pulse feeding with 1 g/L acetate every 48 h led to the alternation between mixotrophy and photoinduction, resulting in a lutein production of 33.6 mg/L. Most notably, excellent lutein content (9.57 mg/g) and productivity (11.57 mg/L/d) were obtained using a new multi-operation integrated strategy, and the achieved levels exceed those reported in most related studies. This work demonstrates the synergistic integration of simple and effective strategies for the enhancement of lutein production in the indigenous microalga C. sorokiniana FZU60 and provides new insight into the highly efficient microalgae-based lutein production.


Assuntos
Chlorella , Microalgas , Biomassa , Luteína
5.
Bioresour Technol ; 275: 416-420, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30626542

RESUMO

The marine microalga Chlamydomonas sp. JSC4 is a potential lutein source with high light tolerance. In this study, light intensity was manipulated to enhance cell growth and lutein production of this microalga. High lutein productivity (5.08 mg/L/d) was achieved under high light irradiation of 625 µmol/m2/s. Further increase in light intensity to 750 µmol/m2/s enhanced the biomass productivity to 1821.5 mg/L/d, but led to a decrease in lutein content. Under high light conditions, most carotenoids and chlorophyll contents decreased, while zeaxanthin and antheraxanthin contents increased. Inspection of gene expression profile shows that the lut1 and zep genes, responsible for lutein synthesis and flow of zeaxanthin into violaxanthin, respectively, were downregulated, while zeaxanthin biosynthesis gene crtZ was upregulated when the microalga was exposed to a high light intensity. This is consistent with the decrease in lutein content and increase in zeaxanthin content under high light exposure.


Assuntos
Chlamydomonas/metabolismo , Luteína/biossíntese , Biomassa , Chlamydomonas/genética , Clorofila/metabolismo , Luz , Transcriptoma , Xantofilas/biossíntese , Zeaxantinas/biossíntese
6.
Bioprocess Biosyst Eng ; 42(3): 435-443, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30467772

RESUMO

The marine microalga Chlamydomonas sp. JSC4 was examined for its potential as a lutein producer. Environmental conditions, including light quality, temperature and light wavelength mixing ratio, were individually altered to enhance the cell growth rate and lutein production in strain JSC4. Results showed that optimal cell growth was obtained under white light and a temperature of 35 °C, while the optimal lutein content was obtained under blue light and a lower temperature of 20-25 °C. The best lutein production occurred when using a mixing ratio of 3:1 (white light: blue light). Strategies related to light quality and temperature (namely, temperature-gradient and two-stage strategies) were then used to further improve lutein production. Among them, the two-stage strategy proved to be effective markedly improving lutein content from 2.52 to 4.24 mg/g and resulting in the highest lutein productivity of 3.25 mg/L/day.


Assuntos
Chlamydomonas/crescimento & desenvolvimento , Luz , Luteína/biossíntese , Microalgas/crescimento & desenvolvimento
7.
Biotechnol J ; 14(4): e1800380, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30520272

RESUMO

Marine microalgae has great potential for lutein production with the advantage of saving fresh water resource. Thus, marine microalga Chlamydomonas sp. JSC4 is investigated as a potential lutein producer in this study. The medium types, nitrate-N and sea salt concentration are individually investigated to promote the cell growth rate and lutein production of JSC4. In Modified Bold Basal 3N medium, cell growth and lutein content are optimal at the nitrate-N concentration of 1000 mg L-1 and sea salt concentration of 2%. In addition, an innovative salinity-gradient strategy is operated to dramatically enhance biomass productivity (560 mg/L/d) and lutein content (3.42 mg g-1 ), resulting in the optimal lutein productivity (1.92 mg/L/d). Overall, this study clearly demonstrates that salinity is a significant inducer of lutein accumulation by strain JSC4 and that lutein production can be successfully optimized using the salinity-gradient strategy, which is beneficial for the outdoor large-scale lutein production in the future.


Assuntos
Técnicas de Cultura Celular por Lotes/métodos , Biomassa , Luteína/biossíntese , Estresse Fisiológico/genética , Chlamydomonas/química , Chlamydomonas/genética , Luteína/química , Microalgas/química , Microalgas/genética , Nitratos/química , Nitratos/metabolismo , Salinidade
8.
Bioresour Technol ; 257: 157-163, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29499497

RESUMO

A complex of water-hyacinth derived pellets immobilized with Chlorella sp. was applied, for the first time, in the bioremediation of Cadmium (Cd). The Cd(II) removal efficiency of the complex was optimized by investigating several parameters, including the pellet materials, algal culture age, and light intensity. Results showed that the Cd(II) removal efficiency was positively related to the algal immobilization efficiency and the algal bioaccumulation capacity. Since higher surface hydrophilicity leads to higher immobilization efficiency, the water-hyacinth leaf biochar pellet (WLBp) was selected as the optimal carrier. A maximum Cd(II) removal efficiency of 92.45% was obtained by the complex of WLBp immobilized with algal cells in stationary growth phase and illuminated with a light intensity of 119 µmol m-2 s-1. Recovery tests on both microalgal cells and the WLBp demonstrated that the algal cells and the biochar pellet can be economically recycled and reused.


Assuntos
Biodegradação Ambiental , Cádmio , Eichhornia , Adsorção , Chlorella , Hyacinthus
9.
Bioresour Technol ; 244(Pt 1): 664-671, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28813692

RESUMO

The type and concentration of inorganic carbon and nitrogen sources were manipulated to improve cell growth and lutein productivity of Desmodesmus sp. F51. Using nitrate as nitrogen source, the better cell growth and lutein accumulation were obtained under 2.5% CO2 supply when compared to the addition of NaHCO3 or Na2CO3. To solve the pH variation problem of ammonium consumption, the strategy of using dual carbon sources (NaHCO3 and CO2) was explored. A lower bicarbonate-C: ammonium-N ratio led to a lower culture pH as well as lower lutein productivity, but significantly enhanced the auto-flocculation efficiency of the microalgal cells. The highest biomass productivity (939mg/L/d) and lutein productivity (5.22mg/L/d) were obtained when the bicarbonate-C/ammonium-N ratio and ammonium-N concentration were 1:1 and 150mg/L, respectively. The lutein productivity of 5.22mg/L/d is the highest value ever reported in the literature using batch phototrophic cultivation.


Assuntos
Carbono , Clorófitas , Luteína , Compostos de Amônio , Biomassa , Microalgas
10.
Bioresour Technol ; 244(Pt 1): 1031-1038, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28847109

RESUMO

The feasibility of the bioremediation of cadmium (Cd) using microalgal-biochar immobilized complex (MBIC) was investigated. Major operating parameters (e.g., pH, biosorbent dosage, initial Cd(II) concentration and microalgal-biochar ratio) were varied to compare the treatability of viable algae (Chlorella sp.), biochar and MBIC. The biosorption isotherms obtained by using algae or biochar were found to have satisfactory Langmuir predictions, while the best fitting adsorption isotherm model for MBIC was the Sips model. The maximum Cd(II) adsorption capacity of MBIC with a Chlorella sp.: biochar ratio of 2:3 (217.41mgg-1) was higher than that of Chlorella sp. (169.92mgg-1) or biochar (95.82mgg-1) alone. The pseudo-second-order model fitted the biosorption process of MBIC well (R2>0.999). Moreover, zeta potential, SEM and FTIR studies revealed that electrostatic attraction, ion exchange and surface complexation were the main mechanisms responsible for Cd removal when using MBIC.


Assuntos
Cádmio , Carvão Vegetal , Microalgas , Purificação da Água , Adsorção , Chlorella , Concentração de Íons de Hidrogênio
11.
Bioresour Technol ; 221: 385-393, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27660989

RESUMO

In this study, five microalgae strains were cultured for their ability to survive in biogas slurry, remove nitrogen resources and accumulate carbohydrates. It was proved that five microalgae strains adapted in biogas slurry well without ammonia inhibition. Among them, Chlorella vulgaris ESP-6 showed the best performance on carbohydrate accumulation, giving the highest carbohydrate content of 61.5% in biogas slurry and the highest ammonia removal efficiency and rate of 96.3% and 91.7mg/L/d respectively in biogas slurry with phosphorus and magnesium added. Additionally, the absence of phosphorus and magnesium that can be adverse for biomass accumulation resulted in earlier timing of carbohydrate accumulation and magnesium was firstly recognized and proved as the influence factor for carbohydrate accumulation. Microalgae that cultured in biogas slurry accumulated more carbohydrate in cell, making biogas slurry more suitable medium for the improvement of carbohydrate content, thus can be regarded as a new strategy to accumulate carbohydrate.


Assuntos
Biocombustíveis/microbiologia , Carboidratos/química , Chlorella vulgaris , Amônia/química , Biomassa , Microalgas , Nitrogênio/química , Fósforo/química
12.
Bioresour Technol ; 180: 281-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25618497

RESUMO

The C-phycocyanin generated in blue-green algae Arthrospira platensis is gaining commercial interest due to its nutrition and healthcare value. In this study, the light intensity and initial biomass concentration were manipulated to improve cell growth and C-phycocyanin production of A.platensis in batch cultivation. The results show that low light intensity and high initial biomass concentration led to increased C-phycocyanin accumulation. The best C-phycocyanin productivity occurred when light intensity and initial biomass concentration were 300µmol/m(2)/s and 0.24g/L, respectively. The fed-batch cultivation proved to be an effective strategy to further enhance C-phycocyanin production of A.platensis. The results indicate that C-phycocyanin accumulation not only requires nitrogen-sufficient condition, but also needs other nutrients. The highest C-phycocyanin content (16.1%), production (1034mg/L) and productivity (94.8mg/L/d) were obtained when using fed-batch strategy with 5mM medium feeding.


Assuntos
Técnicas de Cultura Celular por Lotes/métodos , Ficocianina/biossíntese , Spirulina/crescimento & desenvolvimento , Spirulina/metabolismo , Luz , Nitrogênio/metabolismo , Processos Fototróficos , Spirulina/citologia
13.
Bioresour Technol ; 184: 131-138, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25453431

RESUMO

In this study, the effects of the type and concentration of nitrogen sources on the cell growth and lutein content of an isolated microalga Scenedesmus obliquus FSP-3 were investigated. With batch culture, the highest lutein content (4.61 mg/g) and lutein productivity (4.35 mg/L/day) were obtained when using 8.0 mM calcium nitrate as the nitrogen source. With this best nitrogen source condition, the microalgae cultivation was performed using two bioreactor strategies (namely, semi-continuous and two-stage operations) to further enhance the lutein content and productivity. Using semi-continuous operation with a 10% medium replacement ratio could obtain the highest biomass productivity (1304.8 mg/L/day) and lutein productivity (6.01 mg/L/day). This performance is better than most related studies.


Assuntos
Reatores Biológicos/microbiologia , Luteína/biossíntese , Nitrogênio/farmacologia , Scenedesmus/metabolismo , Técnicas de Cultura Celular por Lotes , Biomassa , Luz , Scenedesmus/citologia , Scenedesmus/efeitos dos fármacos , Scenedesmus/crescimento & desenvolvimento , Scenedesmus/efeitos da radiação , Fatores de Tempo
14.
Bioresour Technol ; 144: 435-44, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23890979

RESUMO

Four indigenous thermo-tolerant Desmodesmus sp. strains were examined for their ability to produce lutein. Among them, Desmodesmus sp. F51 was the best strain for this purpose. The medium composition, nitrate concentration and light intensity were manipulated to improve the phototrophic growth and lutein production of Desmodesmus sp. F51. It was found that a nitrogen-sufficient condition was required for lutein accumulation, while a high light intensity enhanced cell growth but caused a decrease in the lutein content. The best cell growth and lutein production occurred when the light intensity and initial nitrate concentration were 600 µmol/m(2)/s and 8.8 mM, respectively. The fed-batch cultivation strategy was shown to further improve lutein production. The highest lutein productivity (3.56±0.10 mg/L/d) and content (5.05±0.20 mg/g) were obtained when pulse-feeding of 2.2 mM nitrate was employed. This study demonstrated the potential of using Desmodesmus sp. F51 as a lutein producer in practical applications.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Técnicas de Cultura Celular por Lotes/métodos , Clorófitas/crescimento & desenvolvimento , Luz , Luteína/biossíntese , Nitratos/farmacologia , Fototropismo/efeitos dos fármacos , Biomassa , Clorófitas/citologia , Clorófitas/efeitos dos fármacos , Clorófitas/efeitos da radiação , Meios de Cultura/farmacologia , Fototropismo/efeitos da radiação , Pigmentos Biológicos/metabolismo , Temperatura Ambiente , Fatores de Tempo
15.
Bioresour Technol ; 145: 297-301, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23419991

RESUMO

This is the first attempt to study the synergistic effect between Trichoderma reesei cellulases and the abundant agricultural tea waste in absorption of heavy metal Cr(VI) as well as its kinetic model development. The properties of tea waste were first analyzed by near infrared spectroscopy (NIR), particle size distribution (PSD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) examination with EDX for comparison between its original (UN-TW) and cellulase-hydrolyzed (TRCEL-TW) conditions. Then, an advanced kinetic model in the form of -d[Cr(VI)]/dt = A[H+](n)e(-Ea/RT) [Cr(VI)](m)(0), which can successfully predict the time-dependent Cr(VI) concentration of various pHs, initial Cr(VI) concentrations and temperatures was developed. The demonstrated synergistic effects of T. reesei cellulases on tea waste suggested that cellulosic material provides more accessibility area for absorption of heavy metal. This study also provides an alternative approach to remove toxic Cr(VI) from aqueous solutions and extend the utilization of agricultural tea waste.


Assuntos
Celulase/metabolismo , Cromo/isolamento & purificação , Recuperação e Remediação Ambiental/métodos , Folhas de Planta/química , Chá/química , Trichoderma/enzimologia , Resíduos , Adsorção , Sinergismo Farmacológico , Cinética , Microscopia Eletrônica de Varredura , Modelos Biológicos , Tamanho da Partícula , Espectroscopia Fotoeletrônica , Espectroscopia de Luz Próxima ao Infravermelho
16.
Biotechnol Prog ; 29(1): 109-15, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23125192

RESUMO

Natamycin is a type of polyene macrolide antibiotic and has been produced in submerged microbial cultures of some natural Streptomyces strains. Natamycin extraction from cellular biomass is greatly affected by the molecular and solubilization characteristics of the extraction solvent, and this is a major reason for the routine attainment of low volumetric titers, resulting from sparing natamycin solubility. In this work, a series of experiments were conducted to investigate the solubility of natamycin in some selected organic solvents in order to assess the influence on natamycin extraction yield. Natamycin showed the highest solubility in 75% aqueous methanol under the conditions of pH 2, 30°C and 1 atm. Furthermore, the extraction of natamycin using 75% aqueous methanol was performed and the highest extraction yield of 45.7% was obtained under pH 2. A mathematical model derived from Fick's law of the biomolecular diffusion process was developed to fit the experimental kinetic data of natamycin extraction.


Assuntos
Biomassa , Natamicina/isolamento & purificação , Streptomyces/química , Difusão , Natamicina/química , Solubilidade
17.
Nan Fang Yi Ke Da Xue Xue Bao ; 28(4): 609-11, 2008 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-18495604

RESUMO

OBJECTIVE: To establish a method for rapid differential diagnosis of thalassemia trait (TT) and iron-deficiency anemia (IDA) using stepwise regression analysis. METHODS: Stepwise regression equation was established for differential diagnosis of TT and IDA according to the red cell index, and the accuracy of the differential diagnosis was evaluated using blind analysis. RESULTS: The accuracy of this equation for differential diagnosis of TT and IDA was 86.82%. The sensitivity, specificity and Youden's index in prediction of TT and IDA were 94.29%, 79.66%, 73.9 and 76.92%, 90.52%, and 67.4%, respectively. CONCLUSION: The stepwise regression equation using the red cell index is concise, rapid, and sensitive in differential diagnosis of TT and IDA, and can be well applicable in clinical practice.


Assuntos
Anemia Ferropriva/diagnóstico , Talassemia/diagnóstico , Adulto , Anemia Ferropriva/sangue , Diagnóstico Diferencial , Método Duplo-Cego , Feminino , Humanos , Masculino , Análise de Regressão , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Talassemia/sangue
18.
Zhonghua Fu Chan Ke Za Zhi ; 37(4): 214-6, 2002 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-12133413

RESUMO

OBJECTIVE: To assess the predictive value of intrauterine fetal hypoxia by Doppler examination and non-stress test (NST). METHODS: The normal value of the peak-systolic and diastolic ratio (S/D), pulse index (PI), resistance index (RI), fast volume ratio (FVR) of different gestational age was created according to 4 326 normal pregnancy. S/D, PI, RI, FVR and NST was performed for 2 873 normal pregnancy at the last trimester. Fetal outcomes were recorded within 7 days of birth. RESULTS: (1) S/D, PI, and RI decreased with the gestational age advancing, but FVR didn't. When S/D, PI, RI, FVR or NST appeared abnormal, the ratio of intrauterine fetal hypoxia was 62.0%, 60.7%, 63.3%, 27.0% and 75.7% respectively, as these normal, the ratio of intrauterine fetal hypoxia was 12.8%, 13.9%, 13.0%, 15.7%, 7.5% respectively. There was significant difference (P < 0.01). (2) Logistic regression showed that the predictive value of RI and NST to intrauterine fetal hypoxia was significant (P < 0.05). CONCLUSIONS: The predictive value of NST and RI to intrauterine fetal hypoxia was stronger than other parameters. Multi-parameter may predict more accurately than any single index for intrauterine fetal hypoxia.


Assuntos
Hipóxia Fetal/diagnóstico , Velocidade do Fluxo Sanguíneo , Feminino , Frequência Cardíaca Fetal , Humanos , Gravidez , Artérias Umbilicais/fisiologia
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