Effects of the Light Irradiance on the Growth and Lipids Content of Amphidinium Carterae (Dinophyceae) for Biofuels Production

The irradiance level used to the microalgae cultures can modify the growth and proximate composition, however, this response is specie specific. The dinoflagellate group had the potential to be used as a source to biofuel production. In this study was evaluated the effect of five irradiance levels (50, 100, 150, 200, and 250 µmol photon m-2 s­-1) on the growth rate, proximal composition, pigment content, and photosynthesis of Amphidinium carterae. The highest cell concentration was for the cultures at 150 µmol photon m-2 s-1 (130 × 103 cells mL-1), and the lowest values for 50 µmol photon m-2 s-1 (49 × 103 cells mL-1). The cultures maintained under the low irradiance (50 µmol photon m-2 s-1) had the highest values of total dry weight (TDW) (13418 pg cell-1), organic dry weight (ODW) (3836 pg cell-1), and inorganic dry weight (IDW) (9582 pg cell-1). The protein content as the general trend increases significantly concerning the irradiance level, with the higher values (87.47 pg cell-1) at high irradiance (250 µmol photon m-2 s-1). Carbohydrate content was different by the effect of irradiance, with the higher values (32.85 pg cell-1) at the low irradiance used (50 µmol photon m-2 s-1). Lipid content was modified by the effect of irradiance, with the highest values (534.74 pg cell-1) at the low irradiance used (50 µmol photon m-2 s-1). As a general trend, the high irradiances increased the photosynthesis curves. These findings demonstrate that the strain of A. carterae used in this work can grow in high irradiances (100 to 250 µmol photon m-2 s-1) and increase significantly the lipid content on low irradiance used (50 µmol photon m-2 s-1).

Effects of 2-Methoxyestradiol, a Main Metabolite of Estradiol on Hepatic ABCA1 Expression in HepG2 Cells

ATP-binding cassette transporter A1 (ABCA1) is a key regulator of lipid efflux, and the absence of ABCA1 induces hepatic lipid accumulation, which is one of the major causes of fatty liver. 2-Methoxyestradiol (2-ME2) has been demonstrated to protect against fatty liver. In this study, we investigated the effects of 2-ME2 on the hepatic lipid content and ABCA1 expression. We found that 2-ME2 dose-dependently increased ABCA1 expression, and therefore, the lipid content was significantly decreased in HepG2 cells. 2-ME2 enhanced the ABCA1 promoter activity; however, this effect was reduced after the inhibition of the PI3K pathway. The overexpression of Akt or p110 induced ABCA1 promoter activity, while dominant-negative Akt diminished the ability of 2-ME2 on ABCA1 promoter activity. Further, 2-ME2 stimulated the rapid phosphorylation of Akt and FoxO1 and reduced the nuclear accumulation of FoxO1. Chromatin immunoprecipitation confirmed that FoxO1 bonded to the ABCA1 promoter region. The binding was reduced by 2-ME2, which facilitated ABCA1 gene transcription. Furthermore, mutating FoxO1-binding sites in the ABCA1 promoter region or treatment with FoxO1-specific siRNA disrupted the effect of 2-ME2 on ABCA1 expression. All of our results demonstrated that 2-ME2 might upregulate ABCA1 expression via the PI3K/Akt/FoxO1 pathway, which thus reduces the lipid content in hepatocytes.

Palm Oil Mill Effluent for Lipid Production by the Diatom Thalassiosira pseudonana

Biomass and lipid production by the marine centric diatom Thalassiosira pseudonana were characterized in media based on palm oil mill effluent (POME) as a source of key nutrients. The optimal medium comprised 20% by volume POME, 80 µM Na2SiO3, and 35 g NaCl L−1 in water at pH ~7.7. In 15-day batch cultures (16:8 h/h light–dark cycle; 200 µmol photons m−2 s−1, 26 ± 1 °C) bubbled continuously with air mixed with CO2 (2.5% by vol), the peak concentration of dry biomass was 869 ± 14 mg L−1 corresponding to a productivity of ~58 mg L−1 day−1. The neutral lipid content of the biomass was 46.2 ± 1.1% by dry weight. The main components of the esterified lipids were palmitoleic acid methyl ester (31.6% w/w) and myristic acid methyl ester (16.8% w/w). The final biomass concentration and the lipid content were affected by the light–dark cycle. Continuous (24 h light) illumination at the above-specified irradiance reduced biomass productivity to ~54 mg L−1 day−1 and lipid content to 38.1%.

Effect of Dietary Marula Nut Meal on Liver Lipid Content and Surrogate Markers of Liver and Kidney Function of Broiler and Layer Japanese Quail

Marula nut meal (MNM) can substitute soyabean meal (SBM) as a dietary protein source in Japanese quail diets without compromising growth performance and egg production. However, MNM has a high residual oil content which may impact metabolic health. The effects of MNM on hepatic lipid content and general, liver and kidney health have not been determined in both broilers and layers. Accordingly, two studies were run. In the broiler study two hundred 9-days old Japanese quail were randomly allocated to five diets wherein MNM replaced SBM on a crude protein (CP) basis at 0%, 25%, 50%, 75% and 100%, respectively, in both grower and finisher diets. In the layer study, sixty 5-weeks old Japanese maiden hens, individually housed, were randomly allocated to five-layer diets where MNM replaced SBM on a graded CP basis as for the broilers and fed for 8 weeks. At study termination the birds were slaughtered, blood collected and plasma harvested. Livers were excised, weighed and liver lipid content determined. Plasma surrogate markers of general health, liver and kidney function were determined. Dietary MNM had no effect (P > 0.05) on liver lipid content as well plasma surrogate markers of general health, liver and kidney function of the broiler quail. Dietary MNM at 75% of SBM CP significantly increased plasma phosphorus concentration of quail hens compared to that of counterparts fed control. Dietary MNM can be used in broiler and layer Japanese quail diets without risking development of fatty livers and compromising liver and kidney function.

Assessment of Feeding Behavior of the Zoo-Housed Lesser Anteater (Tamandua tetradactyla) and Nutritional Values of Natural Prey

Very little information is available to zoo managers on the nutritional preferences of the lesser anteater, a highly specialized predator. By studying lesser anteater feeding behavior, we expect to contribute to improved management decisions and individual welfare experiences. We studied the response of zoo-housed lesser anteaters (n = 7) to feeders with live ants (Acromyrmex lundi) and termites (Cortaritermes fulviceps), and we also evaluated the nutritional values of these prey. We individually evaluated each lesser anteater (3 sessions), recording activities by camera. We ground insect samples into a coarse meal and evaluated in vitro biochemical parameters (humidity, lipids proteins, ash, and carbohydrates). Lesser anteaters spent more time with termites than with ants and consumed more termites. Ant meal presented a higher protein and lipid content than termite meal (35.28 ± 0.18% vs. 18.19 ± 0.34% and 16.95 ± 0.13% vs. 6.54 ± 0.31%, respectively), and carbohydrate digestibility was higher in termites. These findings indicate an association between the level of insect consumption and nutritional and digestibility values. This is the first exploration of lesser anteater responses to the presence of social insects in feeders and may serve to guide the study of food preferences in captivity.

Fish Liver Discards as a Source of Long chain Omega-3 Polyunsaturated Fatty Acids

The intake of omega-3 polyunsaturated fatty acids (PUFA) of the average consumer is generally low and products like fish oils high in omega-3 PUFA have become a popular dietary supplement. There is a need for more sources of omega-3 PUFA to cover the increasing demand. This study investigated whether livers from different lean fish species could be a potential new source of oils rich in omega-3 PUFA. The seasonal variation in lipid content, fatty acid composition, peroxide value and free fatty acid content of livers from cod, hake, ling, coalfish and monkfish was determined and the effect of storage conditions on the fishing vessel (ice vs frozen) was studied. Generally, the lipid content and composition of the livers from the five fish species varied similarly during the two years of sampling period with significantly lower values in spring (March, April) and higher values in fall (November, October). Storage conditions were found to have no significant effect on the quality and oil composition. Monkfish livers were less suitable for production of omega-3 oil due to their lower lipid and EPA content and higher FFA levels. Coalfish had higher fluctuations in oil composition during sampling period, which potentially makes a standardised quality difficult to obtain. Cod, hake and ling were the most suitable species for fish liver oil production.

High-Content C. elegans Screen Identifies Natural Compounds Impacting Mitochondria-Lipid Homeostasis and Promoting Healthspan

The aging process is concurrently shaped by genetic and extrinsic factors. In this work, we screened a small library of natural compounds, many of marine origin, to identify novel possible anti-aging interventions in Caenorhabditis elegans, a powerful model organism for aging studies. To this aim, we exploited a high-content microscopy platform to search for interventions able to induce phenotypes associated with mild mitochondrial stress, which is known to promote animal’s health- and lifespan. Worms were initially exposed to three different concentrations of the drugs in liquid culture, in search of those affecting animal size and expression of mitochondrial stress response genes. This was followed by a validation step with nine compounds on solid media to refine compounds concentration, which led to the identification of four compounds (namely isobavachalcone, manzamine A, kahalalide F and lutein) consistently affecting development, fertility, size and lipid content of the nematodes. Treatment of Drosophila cells with the four hits confirmed their effects on mitochondria activity and lipid content. Out of these four, two were specifically chosen for analysis of age-related parameters, kahalalide F and lutein, which conferred increased resistance to heat and oxidative stress and extended animals’ healthspan. We also found that, out of different mitochondrial stress response genes, only the C. elegans ortholog of the synaptic regulatory proteins neuroligins, nlg-1, was consistently induced by the two compounds and mediated lutein healthspan effects.

Sexual Dimorphism in Metabolic Responses to Western Diet in Drosophila melanogaster

Obesity is a chronic disease affecting millions of people worldwide. The fruit fly (Drosophila melanogaster) is an interesting research model to study metabolic and transcriptomic responses to obesogenic diets. However, the sex-specific differences in these responses are still understudied and perhaps underestimated. In this study, we exposed adult male and female Dahomey fruit flies to a standard diet supplemented with sugar, fat, or a combination of both. The exposure to a diet supplemented with 10% sugar and 10% fat efficiently induced an increase in the lipid content in flies, a hallmark for obesity. This increase in the lipid content was more prominent in males, while females displayed significant changes in the glycogen content. The strong effects of the diets on the ovarian size and number of mature oocytes were also present in females exposed to diets supplemented with fat and a combination of fat and sugar. In both males and females, the fat body morphology changed and was associated with an increase in the lipid content of fat cells in response to the diets. The expression of metabolism-related genes also displayed a strong sexually dimorphic response under normal conditions and in response to the sugar and/or fat-supplemented diets. Here, we showed that the exposure of adult fruit flies to an obesogenic diet containing both sugar and fat allowed studying sexual dimorphism in metabolism and the expression of genes regulating metabolism.

Extraction, characterization, and optimization of biodiesel production from Pachira aquatica Aubl

Given the great energy demand to meet the needs of modern society, it is essential that new alternatives to replace fossil diesel are studied. And biodiesel is an alternative that has been gaining prominence on the world stage, mainly with the use of vegetable oils with a high lipid content, such as Pachira aquatica Aubl, also known as munguba. Given the above, the objective of this work was to extract the oil from the seeds of Pachira aquatica, evaluate the physicochemical characteristics of the oil and define the best conditions for catalytic mixing with temperature variation in the production of biodiesel from the oil obtained. Thus, the acidity index, saponification, refraction, peroxide, water content and fatty acid profile of the oil were evaluated. Fourteen treatments of biodiesel produced with different amounts of sulfuric acid and temperature were evaluated. They were analyzed for water content, specific mass, kinematic viscosity at 40 ºC, refractive index and ester content. It was found that the lipid content of Pachira aquatica seeds was 42.19% and its physical chemistry analysis showed that it can be used in the production of biofuels. There was a greater presence of saturated fatty acids, with a predominance of palmitic acid with 81.95%. Biodiesel produced from oil, on the other hand, showed higher production of esters in relation to the volume used at temperatures of 60 ºC and 0.6 mL of sulfuric acid, and that its properties showed that the plant can be a possible alternative for the production of biodiesel.