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1.
Artigo em Inglês | MEDLINE | ID: mdl-31845243

RESUMO

The phytoplankton (internal driving forces) and environmental variables that affect complex biochemical reactions (external driving forces) play an important role in regulating photosynthetic carbon fixation. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) exists in various phytoplankton species and is an important enzyme in the photosynthetic process. To investigate the phytoplankton composition (internal driving forces), we selected the functional gene of the Rubisco large subunit (rbcL) as the target gene for this study. Phytoplankton gross primary productivity was measured using light and dark biological oxygen demand bottles to assess the carbon sequestration potential. The fundamental environmental indicators were determined to analyze the mechanisms that drive the carbon fixation process. The correlation results indicated that green algae were only controlled by nitrate, and that diatoms were positively correlated with phosphate. The cluster analysis results demonstrated that nitrite was the major driver controlling phytoplankton primary productivity. During the wet seasons (spring and summer), the contribution of the planktonic community respiration to the carbon sequestration potential was higher than net primary productivity (NPP), followed by dissolved organic carbon and nitrate. During the dry season (autumn), NPP, total nitrogen, and nitrite ranked highest in terms of carbon sequestration potential. The contributions of green algae and diatoms to the carbon sequestration potential were temporally higher than those of cyanobacteria. The maximum carbon sequestration potential occurred during autumn because of diatom production and the function of phosphate, whereas the minimum carbon sequestration potential occurred in summer. Spatially, the upstream carbon sequestration potential was higher compared with downstream because of the effect (contribution) of cyanobacteria (Phormidium), diatoms (Surirella solea and Thalassiosira pseudonana), and environmental variable (nitrite). These findings provide a better understanding of the underlying mechanisms of phytoplankton productivity and the influences of environmental variables on carbon sequestration in urban river ecosystems.

2.
Environ Monit Assess ; 191(11): 688, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664528

RESUMO

Understanding the relative impact sizes of environmental factors and nutrients on the high annual variation of phytoplankton abundance in eutrophic rivers is important for aquatic ecosystem management efforts. In this study, we used phytoplankton dynamic datasets in the eutrophic Fenhe River to show the variations and drivers of phytoplankton abundance under complex, fluctuating environmental conditions during 2012-2017. The temporal and spatial variations of nutrients in the river depicted that the total phosphorus (TP) concentration was higher in the wet season and in downstream. There were increases in total nitrogen (TN) concentration in the normal season and in upstream. The structural equation model (SEM) showed that the phytoplankton abundance increased during the wet season despite the decrease in the TN:TP ratio and was reduced upstream due to the highest TN:TP ratio. Among the environmental variables, water temperature (WT) was an important predictor and positively correlated temporally and spatially to phytoplankton. The interaction of nutrients with the phytoplankton community at different temperature levels indicated that different phytoplankton groups have different nutrient requirements. We can conclude that enhances in temperature and TP concentration will significantly increase phytoplankton abundance and dominance of cyanobacteria and green algae in the future, whereas there was insignificant effect on diatoms. These data indicated that temperature and TP content were the important abiotic factors influencing the phytoplankton growth of the water body, which could provide a reference for the evaluation of environmental alterations in the future.


Assuntos
Monitoramento Ambiental , Fitoplâncton/crescimento & desenvolvimento , Temperatura Ambiente , Poluentes da Água/análise , China , Clorófitas , Cianobactérias/crescimento & desenvolvimento , Diatomáceas/crescimento & desenvolvimento , Ecossistema , Eutrofização , Nitrogênio/análise , Nutrientes , Fósforo/análise , Rios/química , Estações do Ano
3.
Bioresour Technol ; 288: 121568, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31154280

RESUMO

In this study, the performance of Chlorococcum sp. GD in synthetic medium with different glucose concentrations (ranging from 1 to10 g/L) was investigated. Moreover, transcriptome sequencing was conducted to clarify the response of the microalga to glucose concentrations. High concentration of glucose (6-10 g/L) not only did not provide a higher yield of biomass but also inhibited photosynthesis. Transcriptomic analysis revealed that the glucose metabolism mainly depended on the glycolysis and the pentose phosphate pathway (PPP) as the microalga was cultivated with 10 g/L glucose. Meanwhile the tricarboxylic acid (TCA) cycle, oxidative phosphorylation and photosynthesis were significantly inhibited. The significant change on carbon metabolic flux caused by the increase in glucose concentration affected the synthesis of reducing power and ATP, which ultimately influenced the growth of the microalga. Appropriate supplement of organic carbon not only enhances the biomass accumulation but also increases the utilization efficiency of organic carbon.


Assuntos
Fotossíntese , Transcriptoma , Biomassa , Carbono , Glucose
4.
Artigo em Inglês | MEDLINE | ID: mdl-30987041

RESUMO

In order to study the effects of nitrogen stress on the lipid synthesis of Parachlorella kessleri TY02 and to understand the changes in growth, photosynthetic pigments, total protein and total carbohydrate contents during lipid accumulation, the cells of the strain were cultured in nitrogen-deficient (N-) and nitrogen-rich (N⁺) media for one week. Changes in cell growth, chlorophyll content, chlorophyll fluorescence parameters, neutral lipid and total lipid content, total protein content and total carbohydrate content were measured and analyzed. The results showed that, under nitrogen stress, the algal strain grew slowly, and chlorophyll and total protein contents decreased, while total carbohydrate and total lipid contents increased. This indicated that, under nitrogen stress, most of the carbon flowed to the synthesis of lipids and carbohydrates. Meanwhile, reducing the nitrogen content was a relatively economical and easy to operate method of promoting lipid accumulation.


Assuntos
Clorófitas/fisiologia , Metabolismo dos Lipídeos , Estresse Fisiológico , Carboidratos/análise , Carbono/metabolismo , Clorofila/metabolismo , Clorófitas/crescimento & desenvolvimento , Clorófitas/metabolismo , Nitrogênio/metabolismo , Fotossíntese , Proteínas de Plantas/metabolismo
5.
Ecotoxicol Environ Saf ; 171: 274-280, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30612015

RESUMO

There is a concern about the increasing prevalence of health problems related to the ingestion of fluoride (F-) in the developing world. Drinking water is one important source of F-, and the concentration of F- needs to be known to ensure the safety of drinking water. In this study, F- levels in drinking water were investigated across Taiyuan in Shanxi Province, China. Spatial-temporal distribution characteristics and potential associated health risks were analyzed using GIS. We collected 485 samples from shallow wells without any defluoridation treatments between 2008 and 2016. After analyzing the samples of F- content we found that mean F- levels of urban areas (0.61 ±â€¯0.39 mg L-1), suburban areas (0.70 ±â€¯0.87 mg L-1) and for all of Taiyuan city (0.63 ±â€¯0.56 mg L-1) were in optimum range based on the recommendation by USEPA. However, individual locations within industrial areas (e.g. Gujiao District) had higher F- levels (1.06 mg L-1). A concerning result showed that 12.37% of tested locations had F- concentrations larger than 1.0 mg L-1. We calculated F- Health Risk Indices (HRIsF) and found that highest were associated with suburban areas, especially in the year 2009 and 2010. However, from 2008 to 2016, overall F- levels and HRIsF of the sampled groundwater in Taiyuan City showed a decreasing trend. HRIsF in suburban areas was higher than urban areas, possible due to the heavily prevalent coal mining industry in those areas. Specific policies should be formulated to address HRIsF.


Assuntos
Água Potável/química , Fluoretos/análise , Água Subterrânea/química , Poluentes Químicos da Água/análise , China/epidemiologia , Monitoramento Ambiental , Sistemas de Informação Geográfica , Humanos , Medição de Risco , Análise Espaço-Temporal , Saúde Suburbana , Saúde da População Urbana
6.
Colloids Surf B Biointerfaces ; 175: 264-271, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30551013

RESUMO

The development of hepatocyte cultures in vitro holds great significance in the study of bioartificial liver support systems. Electrospun fiber cultures have received widespread attention as an effective method to culture hepatocytes in vitro. Polylactic acid (PLA) -a synthetic polymer with high biocompatibility and biodegradability- is widely used to fabricate electrospun fibers in the biomedical field. However, the use of PLA is limited in cell cultures due to its brittleness, strong hydrophobicity, and lack of biologically active functional groups. In this study, thermoplastic polyurethane (TPU) and lecithin (Lec) were used to modify PLA by spiking them into the PLA electrospun solution in attempt to establish a suitable fiber scaffold for hepatocyte culture in bioreactors. TPU and lecithin incorporation into PLA increases the flexibility, hydrophilicity, and biologically active groups of the fibers which further promotes the growth, proliferation, and viability of hepatocytes. The morphology, wettability, and biocompatibility of the as-prepared PLA-TPU-Lec fibers were carefully characterized. The results showed that the PLA-TPU-Lec fibers possessed favorable morphology and hydrophilicity, as well as high biocompatibility ability. HepG2 cells on the PLA-TPU-Lec fibers and tissue culture plates (TCP) were exposed to hepatotoxins for 24 h and we found that HepG2 cells on the PLA-TPU-Lec fibers had higher viability than cells on TCP. The PLA-TPU-Lec fibers are therefore expected to be used in vitro for hepatocyte culture to improve cellular activity in artificial liver bioreactors.


Assuntos
Materiais Biocompatíveis/farmacologia , Hepatócitos/efeitos dos fármacos , Lecitinas/química , Poliésteres/química , Poliuretanos/química , Materiais Biocompatíveis/química , Reatores Biológicos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Técnicas Eletroquímicas , Células Hep G2 , Hepatócitos/patologia , Humanos , Nanofibras/química
7.
Anal Chem ; 91(1): 888-895, 2019 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-30338985

RESUMO

The development of an effective method for detecting heavy-metal ions remains a serious task because of their high toxicity to public health and environments. Herein, a new electrochemical method based on a graphene aerogel (GA) and metal-organic framework (MOF) composites was developed for simultaneous detection of multiple heavy-metal ions in aqueous solutions. The GA-MOF composites were synthesized via the in situ growth of the MOF UiO-66-NH2 crystal on the GA matrix. GA not only serves as the backbone for UiO-66-NH2 but also enhances the conductivity of the composites by accelerating the electron transfer in the matrix. UiO-66-NH2 worked as a binding site for heavy-metal ions because of the interaction between hydrophilic groups and metal cations. The detection performance of the GA-UiO-66-NH2 composite-modified electrodes was determined. The developed electrochemical method can be successfully applied for individual and simultaneous detection of heavy-metal ions, namely, Cd2+, Pb2+, Cu2+,and Hg2+, in aqueous solutions with high sensitivity and selectivity. The method can also be used for simultaneous detection of Cd2+, Pb2+, Cu2+, and Hg2+ in river water and the leaching solutions of soil and vegetable with high accuracy and reliability. This work provides a new approach for simultaneous detection of multiple heavy-metal ions in practical applications.

8.
Environ Monit Assess ; 191(1): 29, 2018 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-30591969

RESUMO

In this paper, the algal cell density of cyanobacteria, green algae, and diatoms and their responses to the hydrochemical factors were analyzed to reveal the structural characteristics of water quality in an urban river. A total of nine sampling sites from upstream to downstream was explored in our study. At each site, the density of algae was identified every week during the wet season (June-October) from 2012 to 2017, and in situ detection was used for the relative 11 hydrochemical variables. The temporal and spatial characteristics of 14 variables were analyzed using a heatmap coupled with the cluster analysis method. The trend of each parameter was analyzed using the smoothing method with locally weighted regression. The nonmetric multidimensional scaling method was employed to detect the temporal and spatial similarities among algae along hydrochemical gradients. The responses of algal density to hydrochemical variables were analyzed using a redundancy analysis. The results showed that the water temperature (Wtemp), pH, dissolved oxygen (DO), cyanobacteria, and diatoms exhibited significant declining trends, and significant increasing trends were shown in the permanganate index, chemical oxygen demand, total nitrogen, ammonia nitrogen, and total phosphorus; the cyanobacteria exhibited certain differences with green algae and diatoms in summer and the downstream areas of the river. The temporal-spatial homogeneity of algal to hydrochemical variables showed the key influencing factors of Wtemp for cyanobacteria density, chlorophyll for green algae density, DO, and pH for diatoms. The results presented here are valuable for deepening our understanding of river ecosystem evaluations and effective environmental management, as well as an important reference for the sustainable development of aquatic biological resources.


Assuntos
Clorófitas/citologia , Cianobactérias/citologia , Diatomáceas/citologia , Monitoramento Ambiental/métodos , Rios/química , Movimentos da Água , China , Clorofila/análise , Clorófitas/crescimento & desenvolvimento , Cianobactérias/crescimento & desenvolvimento , Diatomáceas/crescimento & desenvolvimento , Ecossistema , Eutrofização , Nitrogênio/análise , Fósforo/análise , Estações do Ano , Urbanização , Qualidade da Água
9.
Molecules ; 23(12)2018 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-30486347

RESUMO

In this study, a non-targeted metabolic profiling method based on ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS) was used to characterize the plasma metabolic profile associated with the protective effects of the Sagittaria sagittifolia polysaccharide (SSP) on isoniazid (INH)-and rifampicin (RFP)-induced hepatotoxicity in mice. Fourteen potential biomarkers were identified from the plasma of SSP-treated mice. The protective effects of SSP on hepatotoxicity caused by the combination of INH and RFP (INH/RFP) were further elucidated by investigating the related metabolic pathways. INH/RFP was found to disrupt fatty acid metabolism, the tricarboxylic acid cycle, amino acid metabolism, taurine metabolism, and the ornithine cycle. The results of the metabolomics study showed that SSP provided protective effects against INH/RFP-induced liver injury by partially regulating perturbed metabolic pathways.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Isoniazida/efeitos adversos , Metaboloma/efeitos dos fármacos , Polissacarídeos/farmacologia , Rifampina/efeitos adversos , Sagittaria/química , Animais , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Isoniazida/farmacologia , Metabolômica , Camundongos , Camundongos Endogâmicos BALB C , Polissacarídeos/química , Rifampina/farmacologia
10.
J Ethnopharmacol ; 227: 237-245, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30194055

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: The Sagittaria sagittifolia L. polysaccharide (SSP) is a purified form of a homogeneous polysaccharide isolated from the root tubers of S. sagittifolia, which has been used as a protectant against hepatotoxicity induced by coadministration of isoniazid and rifampicin. However, the protective effect of SSP against isoniazid- and rifampicin-induced liver injury has never been studied. AIM OF THE STUDY: In this study, the hepatoprotective effect of SSP and its underlying mechanism were investigated in mice with isoniazid- and rifampicin-induced liver injury. MATERIALS AND METHODS: Liver injury was induced in mice by intragastric administration of isoniazid and rifampicin, and the mice were divided into the following six groups: standard control (administration of saline by gavage), model (intragastric administration of isoniazid and rifampicin at 100 mg/kg/day each), positive control (100 mg/kg/day silymarin by gavage 4 h after isoniazid and rifampicin administration), and SSP-treated (200, 400, or 800 mg/kg/day SSP by gavage after isoniazid and rifampicin administration). Subsequently, blood and liver samples were collected from all the animals and were assessed. RESULTS: SSP significantly alleviated the liver injury, as evidenced by decreased activities of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase in the serum and a decreased level of malondialdehyde in the liver, as well as by an increased level of glutathione and increased activities of superoxide dismutase and catalase in the liver. SSP also effectively reduced the pathological tissue damage. The gene and protein expression of cytochrome P450 (CYP) 2E1 and CYP3A4 was inhibited by SSP. The gene and protein expression of nuclear factor erythroid 2-related factor 2 (NRF2), glutamate-cysteine ligase, and heme oxygenase-1 were induced by SSP, whereas that of Kelch-like ECH-associated protein 1 was inhibited. CONCLUSIONS: SSP exerts a protective effect against isoniazid- and rifampicin-induced liver injury in mice. The underlying mechanisms may involve activation of NRF2 and its target antioxidant enzymes and inhibition of the expression of CYPs.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Polissacarídeos/farmacologia , Substâncias Protetoras/farmacologia , Sagittaria , Animais , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/patologia , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP3A/genética , Isoniazida , Masculino , Camundongos Endogâmicos BALB C , Polissacarídeos/uso terapêutico , Substâncias Protetoras/uso terapêutico , Rifampina , Transdução de Sinais/efeitos dos fármacos
11.
Environ Sci Pollut Res Int ; 25(24): 23917-23928, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29881967

RESUMO

The ability of the agricultural residue of Phragmites australis to serve as an absorbent material used to remove phenol from aqueous solutions in batch and continuous fixed-bed columns was investigated. Prepared adsorbents were characterized by SEM, FTIR, and pHpzc methods. The equilibrium adsorption (qe) of phenol was increased from 9.61 to 29.40 mg/g when the initial phenol concentrations increased from 50 to 150 mg/L. The max adsorption capacity of Phragmites australis was found to be 29.60 mg/g at 30 °C. In column studies, a higher flow rate, higher initial concentration of phenol, and shorter packing layer height increase the column adsorption capacity of phenol. In a batch and continuous fixed-bed column studies, the experiment data was evaluated by some classic models. Fitting degree between the experimental results shows that the pseudo-second-order adsorption kinetics and Langmuir model were the best. Thomas and Yoon-Nelson models were in good agreement with the experimental breakthrough curve data. Both batch and continuous investigation indicated that Phragmites australis could be used as a fine adsorbent to remove phenol and that the adsorption efficiency improved significantly in the column experiment.


Assuntos
Fenol/isolamento & purificação , Poaceae/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Cinética , Modelos Teóricos , Fenol/química , Soluções/química , Poluentes Químicos da Água/química , Purificação da Água/instrumentação
12.
Bioresour Technol ; 264: 311-318, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29857286

RESUMO

Chlorella vulgaris was selected from five freshwater microalgal strains of Chlorophyta, and showed a good potential in nutrients removal from undiluted cattle farm wastewater. By the end of treatment, 62.30%, 81.16% and 85.29% of chemical oxygen demand (COD), ammonium (NH4+-N) and total phosphorus (TP) were removed. Then two two-stage processes were established to enhance nutrients removal efficiency for meeting the discharge standards of China. The process A was the biological treatment via C. vulgaris followed by the biological treatment via C. vulgaris, and the process B was the biological treatment via C. vulgaris followed by the activated carbon adsorption. After 3-5 d of treatment of wastewater via the two processes, the nutrients removal efficiency of COD, NH4+-N and TP were 91.24%-92.17%, 83.16%-94.27% and 90.98%-94.41%, respectively. The integrated two-stage process could strengthen nutrients removal efficiency from undiluted cattle farm wastewater with high organic substance and nitrogen concentration.


Assuntos
Chlorella vulgaris , Eliminação de Resíduos Líquidos , Águas Residuárias , Animais , Bovinos , China , Fazendas , Microalgas , Nitrogênio , Fósforo
13.
PLoS One ; 13(5): e0197729, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29813098

RESUMO

The Rhodophyta Sheathia arcuata is exclusively distributed in freshwater, constituting an important component in freshwater flora. This study presents the first transcriptome profiling of freshwater Rhodophyta taxa. A total of 161,483 assembled transcripts were identified, annotated and classified into different biological categories and pathways based on BLAST against diverse databases. Different gene expression patterns were caused principally by different irradiances considering the similar water conditions of the sampling site when the specimens were collected. Comparison results of gene expression levels under different irradiances revealed that photosynthesis-related pathways significantly up-regulated under the weak light. Molecular responses for improved photosynthetic activity include the transcripts corresponding to antenna proteins (LHCA1 and LHCA4), photosynthetic apparatus proteins (PSBU, PETB, PETC, PETH and beta and gamma subunits of ATPase) and metabolic enzymes in the carbon fixation. Along with photosynthesis, other metabolic activities were also regulated to optimize the growing and development of S. arcuata under appropriate sunlight. Protein-protein interactive networks revealed the most responsive up-expressed transcripts were ribosomal proteins. The de-novo transcriptome assembly of S. arcuata provides a foundation for further investigation on the molecular mechanism of photosynthesis and environmental adaption for freshwater Rhodophyta.


Assuntos
Proteínas de Algas/genética , Perfilação da Expressão Gênica/métodos , Rodófitas/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Luz , Anotação de Sequência Molecular , Fotossíntese , Rodófitas/genética , Análise de Sequência de RNA/métodos
14.
Artigo em Inglês | MEDLINE | ID: mdl-29498694

RESUMO

The performance of a self-flocculating microalga Chlorococcum sp. GD on the flocculation, growth, and lipid accumulation in wastewater with different ammonia nitrogen concentrations was investigated. It was revealed that relative high ammonia nitrogen concentration (20-50 mg·L-1) was beneficial to the flocculation of Chlorococcum sp. GD, and the highest flocculating efficiency was up to 84.4%. It was also found that the highest flocculating efficiency occurred in the middle of the culture (4-5 days) regardless of initial ammonia concentration in wastewater. It was speculated that high flocculating efficiency was likely related to the production of extracellular proteins. 20 mg·L-1 of ammonia was found to be a preferred concentration for both biomass production and lipid accumulation. 92.8% COD, 98.8% ammonia, and 69.4% phosphorus were removed when Chlorococcum sp. GD was cultivated in wastewater with 20 mg·L-1 ammonia. The novelty and significance of the investigation was the integration of flocculation, biomass production, wastewater treatment, and lipid accumulation, simultaneously, which made Chlorococcum sp. GD a potential candidate for wastewater treatment and biodiesel production if harvested in wastewater with suitable ammonia nitrogen concentration.


Assuntos
Amônia/metabolismo , Clorofíceas/fisiologia , Microalgas/fisiologia , Nitrogênio/metabolismo , Águas Residuárias , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Biomassa , Floculação , Águas Residuárias/química , Águas Residuárias/microbiologia
15.
J Food Sci ; 82(11): 2591-2597, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29023815

RESUMO

This study examined the effect of Spirulina platensis polysaccharides (SPP) at 0.1%, 0.25%, and 0.5% (wt/wt) of Chinese-style sausages on lipid peroxidation, microbiological and sensory properties during 24 d stored at 4 °C. During the storage, pH, lightness (L* ) values, DPPH radical scavenging activity and sensory scores decreased with time and TBARS, TVB-N, mesophilic, and psychrotrophic total viable counts increased. However, the magnitude of the changes was attenuated with the addition of SPP as compared to control. Samples containing SPP had significantly (P ≤ 0.05) higher DPPH radical scavenging activity and lower TBARS values compared with the control, and the antioxidant effect was dose-dependent. The addition of 0.5% SPP maintained stable redness (a* ) values of sausages, although there was no positive effect on the microbiological status. Moreover, the addition of SPP prevented the decrease of aroma, flavor and sensory acceptance of samples. The results suggested incorporation of SPP could decrease lipid peroxidation and improve sensory properties of Chinese-style sausage. PRACTICAL APPLICATION: There is a great need for adding natural antioxidants to healthier meat and meat products. Spirulina platensis polysaccharides (SPP) had strong antioxidant activity. The addition of SPP to Chinese-style pork sausage could inhibit lipid peroxidation, to extend the shelf life of meat products. SPP were very potential to be used to replace synthetic antioxidants in meat and meat products.


Assuntos
Antioxidantes/análise , Produtos da Carne/análise , Polissacarídeos/análise , Spirulina/química , Animais , Cor , Aromatizantes , Peroxidação de Lipídeos/efeitos dos fármacos , Produtos da Carne/microbiologia , Polissacarídeos/administração & dosagem , Sensação/efeitos dos fármacos , Suínos , Paladar/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico/análise
16.
Sci Rep ; 7(1): 2934, 2017 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-28592899

RESUMO

Freshwater representatives of Rhodophyta were sampled and the complete chloroplast and mitochondrial genomes were determined. Characteristics of the chloroplast and mitochondrial genomes were analyzed and phylogenetic relationship of marine and freshwater Rhodophyta were reconstructed based on the organelle genomes. The freshwater member Compsopogon caeruleus was determined for the largest chloroplast genome among multicellular Rhodophyta up to now. Expansion and subsequent reduction of both the genome size and GC content were observed in the Rhodophyta except for the freshwater Compsopogon caeruleus. It was inferred that the freshwater members of Rhodophyta occurred through diverse origins based on evidence of genome size, GC-content, phylogenomic analysis and divergence time estimation. The freshwater species Compsopogon caeruleus and Hildenbrandia rivularis originated and evolved independently at the inland water, whereas the Bangia atropurpurea, Batrachospermum arcuatum and Thorea hispida are derived from the marine relatives. The typical freshwater representatives Thoreales and Batrachospermales are probably derived from the marine relative Palmaria palmata at approximately 415-484 MYA. The origin and evolutionary history of freshwater Rhodophyta needs to be testified with more organelle genome sequences and wider global sampling.


Assuntos
Evolução Biológica , Água Doce , Rodófitas/classificação , Rodófitas/genética , Evolução Molecular , Genes de Plantas , Variação Genética , Genoma de Cloroplastos , Genoma Mitocondrial , Genômica/métodos , Filogenia
17.
Carbohydr Polym ; 169: 398-405, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28504161

RESUMO

Agricultural plastic films capable of shielding UV, filtering visible light and antifog are important to prolong their life and protect safeties of agriculturists and crops. In this work, high stable and small size TiO2@polymer nanoparticles (NPs) were prepared by an efficient one-pot microwave synthesis using titanic sulfate as Ti resource, carboxymethyl cellulose sodium (CMC) as complexing agent and stabilizer. The TiO2@CMC NPs obtained were then utilized to fabricate poly(ethylene imine) (PEI)/TiO2@CMC coatings on the surface of polypropylene films by a layer-by-layer assembly technique. The TiO2@CMC NPs show rapid deposition rate because small, spherical and anion-rich TiO2@CMC NPs possess large specific surface area and fast diffusion rate. More importantly, property experiments confirm that (PEI/TiO2@CMC)*15 coatings can not only effectively shield UV rays, filter visible light and prevent fogging but also delay the aging of their supports.


Assuntos
Carboximetilcelulose Sódica/química , Titânio/química , Raios Ultravioleta , Agricultura , Nanopartículas
18.
Bioresour Technol ; 234: 289-296, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28334665

RESUMO

Sulfate is a primary sulfur source and can be available in wastewaters. Nevertheless, effect of sulfate ions on growth and pollutants removal of microalgae seems to be less investigated. At the present study, self-flocculating microalga Chlorococcum sp. GD was grown in synthetic municipal wastewater with different sulfate concentrations. Results indicated that Chlorococcum sp. GD grew better in synthetic municipal wastewater with 18, 45, 77, 136 and 271mg/L SO42- than in wastewater without SO42-. Chlorococcum sp. GD had also excellent removal efficiencies of nitrogen and phosphorus and effectively flocculated in sulfate wastewater. Sulfate deprivation weakened the growth, pollutants removal and self-flocculation of Chlorococcum sp. GD in wastewater. Antioxidative enzymes activity significantly increased and photosynthetic activity significantly decreased when Chlorococcum sp. GD was cultivated in sulfate-free wastewater. Sulfate deprivation probably reduced cell activity of growth, pollutants removal and flocculation via inducing the over-accumulation of reactive oxygen species (ROS).


Assuntos
Microalgas , Águas Residuárias , Clorófitas , Fósforo , Sulfatos
19.
Int J Mol Sci ; 18(1)2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28045437

RESUMO

Eutrophication of water catchments and the greenhouse effect are major challenges in developing the global economy in the near future. Secondary effluents, containing high amounts of nitrogen and phosphorus, need further treatment before being discharged into receiving water bodies. At the same time, new environmentally friendly energy sources need to be developed. Integrating microalgal cultivation for the production of biodiesel feedstock with the treatment of secondary effluent is one way of addressing both issues. This article provides a comprehensive review of the latest progress in microalgal cultivation in secondary effluent to remove pollutants and accumulate lipids. Researchers have discovered that microalgae remove nitrogen and phosphorus effectively from secondary effluent, accumulating biomass and lipids in the process. Immobilization of appropriate microalgae, and establishing a consortium of microalgae and/or bacteria, were both found to be feasible ways to enhance pollutant removal and lipid production. Demonstrations of pilot-scale microalgal cultures in secondary effluent have also taken place. However there is still much work to be done in improving pollutants removal, biomass production, and lipid accumulation in secondary effluent. This includes screening microalgae, constructing the consortium, making use of flue gas and nitrogen, developing technologies related to microalgal harvesting, and using lipid-extracted algal residues (LEA).


Assuntos
Poluentes Ambientais/isolamento & purificação , Microalgas/crescimento & desenvolvimento , Nitrogênio/isolamento & purificação , Fósforo/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Biomassa , Poluentes Ambientais/metabolismo , Metabolismo dos Lipídeos , Microalgas/metabolismo , Nitrogênio/metabolismo , Fósforo/metabolismo
20.
PLoS One ; 11(10): e0164744, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27741305

RESUMO

Phenol components are major industry contaminants of aquatic environment. Among all practical methods for removing phenol substances from polluted water, activated carbon absorption is the most effective way. Here, we have produced low-cost activated carbon using Polygonum orientale Linn, a wide spreading species with large biomass. The phenol adsorption ability of this activated carbon was evaluated at different physico-chemical conditions. Average equilibrium time for adsorption was 120 min. The phenol adsorption ability of the P. orientale activated carbon was increased as the pH increases and reached to the max at pH 9.00. By contrast, the ionic strength had little effect on the phenol absorption. The optimum dose for phenol adsorption by the P. orientale activated carbon was 20.00 g/L. The dominant adsorption mechanism of the P. orientale activated carbon was chemisorption as its phenol adsorption kinetics matched with the pseudo-second-order kinetics. In addition, the equilibrium data were fit to the Langmuir model, with the negative standard free energy and the positive enthalpy, suggesting that adsorption was spontaneous and endothermic.


Assuntos
Carvão Vegetal/química , Fenol/química , Polygonum/química , Poluentes Químicos da Água/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Concentração Osmolar , Polygonum/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Termodinâmica , Fatores de Tempo
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