Association of SNP3 polymorphism in the apolipoprotein A-V gene with plasma triglyceride level in Tunisian type 2 diabetes

BACKGROUND: Apolipoprotein A-V (Apo A-V) gene has recently been identified as a new apolipoprotein involved in triglyceride metabolism. A single nucleotide polymorphism (SNP3) located in the gene promoter (-1131) was associated with triglyceride variation in healthy subjects. In type 2 diabetes the triglyceride level increased compared to healthy subjects. Hypertriglyceridemia is a risk factor for coronary artery disease. We aimed to examine the interaction between SNP3 and lipid profile and coronary artery disease (CAD) in Tunisian type 2 diabetic patients. RESULTS: The genotype frequencies of T/T, T/C and C/C were 0.74, 0.23 and 0.03 respectively in non diabetic subjects, 0.71, 0.25 and 0.04 respectively in type 2 diabetic patients. Triglyceride level was higher in heterozygous genotype (-1131 T/C) of apo A-V (p = 0.024). Heterozygous genotype is more frequent in high triglyceride group (40.9%) than in low triglyceride group (18.8%) ; p = 0.011. Despite the relation between CAD and hypertriglyceridemia the SNP 3 was not associated with CAD. CONCLUSION: In type 2 diabetic patients SNP3 is associated with triglyceride level, however there was no association between SNP3 and coronary artery disease

Understanding the cumulative effects of salinity, temperature and inoculation size for the design of optimal halothermotolerant bioanodes from hypersaline sediments

The main objective of this study was to understand the interaction between salinity, temperature and inoculum size and how it could lead to the formation of efficient halothermotolerant bioanodes from the Hypersaline Sediment of Chott El Djerid (HSCE). Sixteen experiments on bioanode formation were designed using a Box-Behnken matrix and response surface methodology to understand synchronous interactions. All bioanode formations were conducted on 6 cm2 carbon felt electrodes polarized at −0.1 V/SCE and fed with lactate (5 g/L) at pH 7.0. Optimum levels for salinity, temperature and inoculum size were predicted by NemrodW software as 165 g/L, 45 °C and 20%, respectively, under which conditions maximum current production of 6.98 ± 0.06 A/m2 was experimentally validated. Metagenomic analysis of selected biofilms indicated a relative abundance of the two phyla Proteobacteria (from 85.96 to 89.47%) and Firmicutes (from 61.90 to 68.27%). At species level, enrichment of Psychrobacter aquaticus, Halanaerobium praevalens, Psychrobacter alimentaris, and Marinobacter hydrocarbonoclasticus on carbon-based electrodes was correlated with high current production, high salinity and high temperature. Members of the halothermophilic bacteria pool from HSCE, individually or in consortia, are candidates for designing halothermotolerant bioanodes applicable in the bioelectrochemical treatment of industrial wastewater at high salinity and temperature

Understanding the cumulative effects of salinity, temperature and inoculation size for the design of optimal halothermotolerant bioanodes from hypersaline sediments

The main objective of this study was to understand the interaction between salinity, temperature and inoculum size and how it could lead to the formation of efficient halothermotolerant bioanodes from the Hypersaline Sediment of Chott El Djerid (HSCE). Sixteen experiments on bioanode formation were designed using a Box-Behnken matrix and response surface methodology to understand synchronous interactions. All bioanode formations were conducted on 6 cm2 carbon felt electrodes polarized at −0.1 V/SCE and fed with lactate (5 g/L) at pH 7.0. Optimum levels for salinity, temperature and inoculum size were predicted by NemrodW software as 165 g/L, 45 °C and 20%, respectively, under which conditions maximum current production of 6.98 ± 0.06 A/m2 was experimentally validated. Metagenomic analysis of selected biofilms indicated a relative abundance of the two phyla Proteobacteria (from 85.96 to 89.47%) and Firmicutes (from 61.90 to 68.27%). At species level, enrichment of Psychrobacter aquaticus, Halanaerobium praevalens, Psychrobacter alimentaris, and Marinobacter hydrocarbonoclasticus on carbon-based electrodes was correlated with high current production, high salinity and high temperature. Members of the halothermophilic bacteria pool from HSCE, individually or in consortia, are candidates for designing halothermotolerant bioanodes applicable in the bioelectrochemical treatment of industrial wastewater at high salinity and temperature

Microbial Exopolysaccharides as Alternative Sources of Dietary Fibers with Interesting Functional and Healthy Properties

Traditional polysaccharides obtained from plants may suffer from a lack of reproducibility in their rheological properties, purity, supply and cost. Most of the used plant polysaccharides are chemically modified to improve their characteristics. Microbial exopolysaccharides (EPSs) are principally composed of carbohydrate polymers, and they are produced by many microorganisms including bacteria, yeasts and fungi. Microorganisms can synthesize EPSs and excrete them out of cell either as soluble or insoluble polymers. These EPSs are able not only to protect the microorganisms themselves against desiccation, phage attack, antibiotics or toxic compounds, but also can be applied in several biotechnological applications. In food products they increase the dietary fiber content and can be used as viscosifiers, stabilizers, emulsifiers or gelling agents to improve physical and structural properties of water and oil holding capacity, viscosity, texture, sensory characteristics and shelf-life. EPSs are used as additives in various foods, such as dairy products, jams and jellies, wine and beer, fishery and meat products, icings and glazes, frozen foods and bakery products. Over the past few decades, interest in using microbial EPSs in food processing has been increasing because of main reasons such as easy production, better rheological and stability characteristics, cost effectiveness and supply. Dextran, xanthan, pullulan, curdlan, levan and gellan and alginate are the main examples of industrially important microbial exopolysaccharides. They also play crucial role in conferring beneficial physiological effects on human health, such as the ability to lower pressure and to reduce lipid level in blood. Furthermore, these EPSs exhibit antitumor, immunomodulating, antioxidant and antibacterial properties. The utility of various biopolymers are dependent on their monosaccharide composition, type of linkages present, degree of branching and molecular weight. In the present chapter, an attempt was taken to recapitulate the most important polysaccharides isolated from microorganisms as well as the main methods for microbial exopolysaccharide production, purification and structural characterization. In addition, the functional and healthy benefits of EPSs and their applications in food industry were described

Optimization of enzymatic saccharification of Chaetomorpha linum biomass for the production of macroalgae-based third generation bioethanol

To evaluate the efficacy of marine macro-algae Chaetomorpha linum as a potential biofuel resource, the effects of the enzymatic treatment conditions on sugar yield were evaluated using a three factor three level Box-Behnken design. The hydrothermally pretreated C. linum biomass was treated with Aspergillus niger cellulase at various liquid to solid ratios (50–100 mL/g), enzyme concentrations (10–60 U/g) and incubations times (4–44 h). Data obtained from the response surface methodology were subjected to the analysis of variance and analyzed using a second order polynomial equation. The fitted model was found to be robust and was used to optimize the sugar yield (%) during enzymatic hydrolysis. The optimum saccharification conditions were: L/S ratio 100 mL/g; enzyme concentration 52 U/g; and time 44 h. Their application led to a maximum sugar yield of 30.2 g/100g dry matter. Saccharomyces cerevisiae fermentation of the algal hydrolysate provided 8.6 g ethanol/100g dry matter. These results showed a promising future of applying C. linum biomass as potential feedstock for third generation bioethanol production

Allometric growth patterns and development in larvae and juveniles of thick-lipped grey mullet Chelon labrosus reared in mesocosm conditions

Allometric growth and ontogeny were studied in thick-lipped grey mullet Chelon labrosus reared in mesocosms from 1 to 71 day post hatching (dph). Multivariate allometric analysis of morphometric growth distinguished three distinct developmental stanzas separated by two morphometric metamorphosis lengths (L-m1=4.46 +/- 0.06mm; L-m2= 28.56 +/- 1.04mm). Body mass growth also showed three distinct episodes separated by two inflections, correlated with morpho-functional changes. First episode concerned pre-flexion larvae and ended around 4.5mm-L-T (14-dph), coinciding with estimated L-m1. It was distinguished by reduced growth, but intense morphogenesis and differentiation processes. Organogenesis and allometric changes indicated that development priorities concerned feeding efficiency, by improving detection ability (sensory system development), ingestion capacity (head growth) and assimilation performance (digestive system differentiation), together with respiration efficiency (gill development). Second episode concerned post-flexion larvae and, ended around 8.6mm-L-T (25-dph). It was distinguished by fast growth of trunk and tail, acquisition of adult axial muscle distribution and completion of gill filament development, improving locomotion and oxygenation performances. It corresponded to transition towards metamorphosing stage as indicated by later isometric growth, musculature maturation and acquisition of juvenile phenotype. Metamorphosis seemed to end at L-m2, suggesting to avoid zootechnic handling before this size

Dimethyl fumarate and monomethyl fumarate attenuate oxidative stress and mitochondrial alterations leading to oxiapoptophagy in 158N murine oligodendrocytes treated with 7β-hydroxycholesterol

International audienceOxidative stress and mitochondrial dysfunction contribute to the pathogenesis of neurodegenerative diseases and favor lipid peroxidation, leading to increased levels of 7β-hydroxycholesterol (7β-OHC) which induces oxiapoptophagy (OXIdative stress, APOPTOsis, autoPHAGY). The cytoprotective effects of dimethylfumarate (DMF), used in the treatment of relapsing remitting multiple sclerosis and of monomethylfumarate (MMF), its main metabolite, were evaluated on murine oligodendrocytes 158 N exposed to 7β-OHC (50 μM, 24 h) with or without DMF or MMF (25 μM). The activity of 7β-OHC in the presence or absence DMF or MMF was evaluated on several parameters: cell adhesion; plasma membrane integrity measured with propidium iodide (PI), trypan blue and fluoresceine diacetate (FDA) assays; LDH activity; antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)); generation of lipid peroxidation products (malondialdehyde (MDA), conjugated dienes (CDs)) and protein oxidation products (carbonylated proteins (CPs)); reactive oxygen species (ROS) overproduction conducted with DHE and DHR123. The effect on mitochondria was determined with complementary criteria: measurement of succinate dehydrogenase activity, evaluation of mitochondrial potential (ΔΨm) and mitochondrial superoxide anions (O2●−) production using DiOC6(3) and MitoSOX, respectively; quantification of mitochondrial mass with Mitotracker Red, and of cardiolipins and organic acids. The effects on mitochondrial and peroxisomal ultrastructure were determined by transmission electron microscopy. Intracellular sterol and fatty acid profiles were determined. Apoptosis and autophagy were characterized by staining with Hoechst 33,342, Giemsa and acridine orange, and with antibodies raised against caspase-3 and LC3. DMF and MMF attenuate 7β-OHC-induced cytotoxicity: cell growth inhibition; decreased cell viability; mitochondrial dysfunction (decrease of succinate dehydrogenase activity, loss of ΔΨm, increase of mitochondrial O2●− production, alteration of the tricarboxilic acid (TCA) cycle, and cardiolipins content); oxidative stress induction (ROS overproduction, alteration of GPx, CAT, and SOD activities, increased levels of MDA, CDs, and CPs); changes in fatty acid and cholesterol metabolism; and cell death induction (caspase-3 cleavage, activation of LC3-I in LC3-II). Ultrastructural alterations of mitochondria and peroxisomes were prevented. These results demonstrate that DMF and MMF prevent major dysfunctions associated with neurodegenerative diseases: oxidative stress, mitochondrial dysfunction, apoptosis and autophagy