http://aoatools.aua.gr/pilotec/files/bibliography/Biofuels%20(alcohols%20and%20biodiesel)%20applications%20as%20fuels%20for%20internal-4026835713/Biofuels%20(alcohols%20and%20biodiesel)%20applications%20as%20fuels%20for%20internal.pdf

Biofuels (alcohols and biodiesel) applications as fuels for internal combustion engines

Plant cells encase themselves within a complex polysaccharide wall, which constitutes the raw material that is used to manufacture textiles, paper, lumber, films, thickeners and other products. The plant cell wall is also the primary source of cellulose, the most abundant and useful biopolymer on the Earth. The cell wall not only strengthens the plant body, but also has key roles in plant growth, cell differentiation, intercellular communication, water movement and defence. Recent discoveries have uncovered how plant cells synthesize wall polysaccharides, assemble them into a strong fibrous network and regulate wall expansion during cell growth.

/pdf/growth-of-the-plant-cell-wall-4k81okl2ih.pdf

Growth of the plant cell wall

Biodiesel is a renewable transportation fuel consisting of fatty acid methyl esters (FAME), generally produced by transesterification of vegetable oils and animal fats. In this review, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized. Considerable compositional variability exists across the range of feedstocks. For example, coconut, palm and tallow contain high amounts of saturated FA; while corn, rapeseed, safflower, soy, and sunflower are dominated by unsaturated FA. Much less information is available regarding the FA profiles of algal lipids that could serve as biodiesel feedstocks. However, some algal species contain considerably higher levels of poly-unsaturated FA than is typically found in vegetable oils. Differences in chemical and physical properties among biodiesel fuels can be explained largely by the fuels’ FA profiles. Two features that are especially influential are the size distribution and the degree of unsaturation within the FA structures. For the 12 biodiesel types reviewed here, it was shown that several fuel properties – including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics – are highly correlated with the average unsaturation of the FAME profiles. Due to opposing effects of certain FAME structural features, it is not possible to define a single composition that is optimum with respect to all important fuel properties. However, to ensure satisfactory in-use performance with respect to low temperature operability and oxidative stability, biodiesel should contain relatively low concentrations of both long-chain saturated FAME and poly-unsaturated FAME.

Review of biodiesel composition, properties, and specifications

Recent Advances in Polyoxometalate-Catalyzed Reactions

Biodiesel is a domestic and renewable alternative with the potential to replace some of the petrodiesel market. It is obtained from vegetable oils, animal fats, or other sources with a significant content of triacylglycerols by means of a transesterification reaction. The fatty acid profile of biodiesel thus corresponds to that of the parent oil or fat and is a major factor influencing fuel properties. Besides being renewable and of domestic origin, advantages of biodiesel compared to petrodiesel include biodegradability, higher flash point, reduction of most regulated exhaust emissions, miscibility in all ratios with petrodiesel, compatibility with the existing fuel distribution infrastructure, and inherent lubricity. Technical problems with biodiesel include oxidative stability, cold flow, and increased NOx exhaust emissions. Solutions to one of these problems often entail increasing the problematic behavior of another property and have included the use of additives or modifying the fatty acid compositi...

“Designer” Biodiesel: Optimizing Fatty Ester Composition to Improve Fuel Properties†

Genes for the enzymes that make plant cell wall hemicellulosic polysaccharides remain to be identified. We report here the isolation of a complementary DNA (cDNA) clone encoding one such enzyme, mannan synthase (ManS), that makes the beta-1, 4-mannan backbone of galactomannan, a hemicellulosic storage polysaccharide in guar seed endosperm walls. The soybean somatic embryos expressing ManS cDNA contained high levels of ManS activities that localized to Golgi. Phylogenetically, ManS is closest to group A of the cellulose synthase-like (Csl) sequences from Arabidopsis and rice. Our results provide the biochemical proof for the involvement of the Csl genes in beta-glycan formation in plants.

https://science.sciencemag.org/content/sci/303/5656/363.full.pdf

Guar Seed ß-Mannan Synthase Is a Member of the Cellulose Synthase Super Gene Family

▪ Abstract In many plants lipids represent up to 80% of dry weight of storage tissues. In seeds, lipids accumulate as triacylglycerols (TAGs), which are formed by an extension of the membrane-lipid biosynthetic pathway common to all plant tissues. In contrast to the conserved fatty acid (FA) composition of membrane lipids, the observed divergence in seed oil acyl chains among different species is very high. The acyl groups of seed TAGs can vary in their chain length (from 8 to 24) as well as in their degree of unsaturation. In addition to methylene-interrupted double bonds, many seeds contain TAGs that have unusual functional groups in their FAs, such as hydroxyl, oxirane, or acetylene groups. All of the major steps in the biosynthetic pathway to TAG are now known and sequence information for genes encoding most of the enzymes involved is available. Here we present the current knowledge of the metabolic mechanisms involved in the divergence from the membrane-lipid biosynthetic pathway during storage lipid...

Variations in the biosynthesis of seed-storage lipids.

The increasing use of soybean (Glycine max) products in processed foods poses a potential threat to soybean-sensitive food-allergic individuals. In vitro assays on soybean seed proteins with sera from soybean-sensitive individuals have immunoglobulin E reactivity to abundant storage proteins and a few less-abundant seed proteins. One of these low abundance proteins, Gly m Bd 30 K, also referred to as P34, is in fact a major (i.e. immunodominant) soybean allergen. Although a member of the papain protease superfamily, Gly m Bd 30 K has a glycine in the conserved catalytic cysteine position found in all other cysteine proteases. Transgene-induced gene silencing was used to prevent the accumulation of Gly m Bd 30 K protein in soybean seeds. The Gly m Bd 30 K-silenced plants and their seeds lacked any compositional, developmental, structural, or ultrastructural phenotypic differences when compared with control plants. Proteomic analysis of extracts from transgenic seed detected the suppression of Gly m Bd 30 K-related peptides but no other significant changes in polypeptide pattern. The lack of a collateral alteration of any other seed protein in the Gly m Bd 30 K-silenced seeds supports the presumption that the protein does not have a role in seed protein processing and maturation. These data provide evidence for substantial equivalence of composition of transgenic and non-transgenic seed eliminating one of the dominant allergens of soybean seeds.

http://www.plantphysiol.org/content/plantphysiol/132/1/36.full.pdf

Genetic Modification Removes an Immunodominant Allergen from Soybean

The preparation and use of nucleic acid fragments encoding fatty acid desaturase enzymes are described. The invention permits alteration of plant lipid composition. Chimeric genes incorporating such nucleic acid fragments with suitable regulatory sequences may be used to create transgenic plants with altered levels of unsaturated fatty acids.

Anthony J. Kinney

Papers

Guar Seed ß-Mannan Synthase Is a Member of the Cellulose Synthase Super Gene Family

Variations in the biosynthesis of seed-storage lipids.

Genetic Modification Removes an Immunodominant Allergen from Soybean

Fatty acid desaturase genes from plants

Modifying soybean oil for enhanced performance in biodiesel blends