In recent decades, the concern over depletion of the world׳s petroleum reserves and environmental pollution has increased the demand to develop a renewable and environmental friendly fuel. Biodiesel, which mainly consists of Fatty Acid Methyl Esters (FAME) is one of the best substitutes for diesel fuel. Currently, vegetable oils, edible or non-edible, are the main resources of biodiesel. This review aims at providing comprehensive information and analyzes on biodiesel produced from edible and non-edible vegetable oils, their composition and specifications. Accordingly, the Fatty Acid (FA) profiles of 28 edible vegetable oils and 40 non-edible vegetable oils were collected. Their main specifications including sulfur content, density, viscosity, flash point, cloud point, pour point, cold filter plugging point, cetane number, iodine number, heating value, acid value and carbon residual before and after transesterification (vegetable oil and biodiesel, respectively) were analyzed in detail. Many researchers have developed prediction models to quantify biodiesel specifications to optimize its manufacturing and obtain biodiesel with the best specifications. Three factors that are especially influential are the fatty acids profiles, the degree of unsaturation within the FA structures and molecular weight. Accordingly, many models have been constructed on these features. There are also models that quantify the relationship between the biodiesel specifications and its thermodynamic properties or other specifications. Accordingly, the second part of this work was conducted on the existing prediction models. All the models were discussed along with their deviation in prediction.

A comprehensive review on properties of edible and non-edible vegetable oil-based biodiesel: Composition, specifications and prediction models

NOx emission of biodiesel compared to diesel: Higher or lower?

Solid state fermentation of food waste mixtures for single cell protein, aroma volatiles and fat production.

Seeds recovered from industry by-products of nine fruit species with a high potential utility as a source of unconventional oil for biodiesel and cosmetic and pharmaceutical sectors.

Cell genetics, culture conditions and the recovery efficiency of cells and products are the bottlenecks for industrial bioprocesses from microalgae. Microalgae lipids can be used for different applications, e.g., drugs, food, and biofuels, and their purpose considers the nature and concentration of the lipids that are wished to obtain. For the biotechnological production of lipids, adequate culture conditions are necessary to enable the cell strain to obtain high biomass and lipid yields and productivities. Also, the processes of separating the cells from the culture medium and releasing the lipids from that biomass need to be efficient and economically viable. Considering that cultivation, cell recovery and lipid extraction directly reflect the results obtained, the most appropriate methods for these operations must be applied. Many literature reviews report the lipid and fatty acid contents obtained through the cultivation of different microalgae species and strains. However, few studies relate the contents of these biomolecules, either with the methods of obtaining the biomass or with the extraction of lipids. Even so far there is no review in the literature with such an approach. The aim of this work was to review and discuss the culture conditions for different microalgae strains and their influence on lipid content; the separation of microalgae biomass, including biomass thickening methods, and methods of biomass depletion; the methods of cellular disruption and lipid extraction; the influence on biofuels’ production, e.g. biodiesel, bioalcohols and biohydrogen; and the influence of green chemistry (solvents and extraction technologies) for a sustainable production of biofuels under the concept of biorefinery.

Biomass recovery and lipid extraction processes for microalgae biofuels production: A review

Influence of fatty acid composition of woody biodiesel plants on the fuel properties

Both environmental exposure to vanadium pentoxide (V2O5, V+5 for its ionic counterparts) and fibroblast senescence are associated with pulmonary fibrosis, but whether V+5 causes fibroblast senescence remains unknown. We found in a dose-response study that 2–40 μM V+5 caused human lung fibroblasts (HLF) senescence with increased senescence-associated β-galactosidase activity and p16 expression, while cell death occurred at higher concentration (LC50, 82 μM V+5). Notably, measures of reactive oxygen species (ROS) production with fluorescence probes showed no association of ROS with V+5-dependent senescence. Preloading catalase (polyethylene-conjugated), a H2O2 scavenger, did not alleviate the cellular senescence induced by V+5. Analyses of the cellular glutathione (GSH) system showed that V+5 oxidized GSH, increased GSH biosynthesis, stimulated cellular GSH efflux and increased protein S-glutathionylation, and addition of N-acetyl cysteine inhibited V+5-elevated p16 expression, suggesting that thiol oxidation mediates V+5-caused senescence. Moreover, strong correlations between GSSG/GSH redox potential (Eh), protein S-glutathionylation, and cellular senescence (R2 > 0.99, p < 0.05) were present in V+5-treated cells. Studies with cell-free and enzyme-free solutions showed that V+5 directly oxidized GSH with formation of V+4 and GSSG in the absence of O2. Analyses of V+5 and V+4 in HLF and culture media showed that V+5 was reduced to V+4 in cells and that a stable V+4/V+5 ratio was rapidly achieved in extracellular media, indicating ongoing release of V+4 and reoxidation to V+5. Together, the results show that V+5-dependent fibroblast senescence is associated with a cellular/extracellular redox cycling mechanism involving the GSH system and occurring under conditions that do not cause cell death. These results establish a mechanism by which environmental vanadium from food, dietary supplements or drinking water, can cause or contribute to lung fibrosis in the absence of high-level occupational exposures and cytotoxic cell death. 

https://doi.org/10.1016/j.redox.2022.102409

Xiao-hui He

Papers

Influence of fatty acid composition of woody biodiesel plants on the fuel properties

Vanadium pentoxide induced oxidative stress and cellular senescence in human lung fibroblasts

Low dose cadmium potentiates metabolic reprogramming following early-life respiratory syncytial virus infection.

Dietary Phytochelatins and Their Impact on Selenium Reuptake

Metabolomics of V2O5 nanoparticles and V2O5 nanofibers in human airway epithelial BEAS-2B cells.