Currently, food industries use supplements fromAloe veraas highly concentrated powders (starting products), which are added to the final product at a concentration of 1x, meaning 10 g/L for decolourized and spray-dried whole leaf powder (WLP) or 5 g/L for decolourized and spray-dried inner leaf powder (ILG) and also for nondecolourized and belt-dried inner leaf powder (ILF). Flavonoids, tannins, or saponins could not be detected for any starting product at this concentration and their total phenol concentration of 68–112 μM gallate-eq. was much lower than in fresh extract; however, their antioxidant capacity of 90–123 μM ascorbate-eq. for DPPH was similar to the fresh extract. Starting products, dissolved at 1x, had an aloin concentration of 0.04 to 0.07 ppm, a concentration much lower than the industry standard of 10 ppm for foodstuff. While decolourized starting products (i.e., treated with activated carbon) exhibited low cytotoxicity on HeLa cells (CC50= 15 g/L ILG or 50 g/L WLP), ILF at CC50= 1–5 g/L exhibited cytotoxic effects, that is, at concentrations even below the recommended for human consumption. Probable causes for the cytotoxicity of ILF are the exposure to high temperatures (70–85°C) combined with a high fibre content.

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The biological activity of Ruta graveolens leaf tissue extracts obtained with different solvents (ethyl acetate, ethanol, and water) and metabolites (psoralen, 2-undecanone and rutin) against Spodoptera frugiperda was evaluated. Metabolites levels in extracts were quantified by HPLC and GC. Ethyl acetate and ethanol extracts showed 94% and 78% mortality, respectively. Additionally, psoralen metabolite showed a high mortality as cypermethrin. Metabolite quantification in extracts shows the presence of 2-undecanone (87.9 μmoles mg−1 DW), psoralen (3.6 μmoles mg−1 DW) and rutin (0.001 μmoles mg−1 DW). We suggest that these concentrations of 2-undecanone and psoralen in R. graveolens leaf tissue extracts could be responsible for S. frugiperda mortality.

Wild piquin pepper fruits are consumed and traded because of their flavor, nutritional and pharmaceutical properties. The heterogeneous germination of its seeds has caused pregermination treatments to be unstandardized. Because of that, our goal was to evaluate pregermination treatments of piquin pepper seeds from a wild plant from the municipality of Victoria, Tamaulipas, Mexico, consisting of immersion for different periods (2, 24, 48 h) in solutions with variable concentrations of the growth regulators naphthalene acetic acid (NAA; 0.1, 1.0, 2.5 mM), salicylic acid (SA; 1.0, 5.0, 10 mM), gibberellic acid (GA3, 1.0, 5.0, 10 mM), indole-3-butyric acid (IBA; 1.0, 2.0, 3.0 mM), the commercial product Biozyme (Bioz) containing minerals and growth regulators (Bioz; 0.5, 1, 2%), and sulfuric acid (H2SO4; 2, 5, 10%) in a completely randomized design, using distilled water as the control. For each treatment, we measured the imbibition ratio, germination percentage, time to obtain 50% germination (T50), and coefficient of variation of germination time (CVt). Our results showed that the imbibition was similar in the control and the treatments, but it differed between treatments. The highest imbibition recorded in 48 h was 87%. The highest germination percentage (79.2%) was achieved with 2 h immersion in 2% Bioz, followed by 1 mM NAA (62%) and 5 mM SA (56%). T50 and CVt were 10-26 d and 0-39%, respectively. According to our results, we concluded that the pregermination treatments we assayed improved the physiological potential for the germination of piquin pepper seeds.

SUMMARY Biofuels have been shown to be a promising and highly attractive alternative for minimizing the use of fossil fuels, and microalgae have positioned themselves as potential candidates for production of lipids and other substances of commercial interest. We briefly review recent advances made in microalgae culture conditions and genetic manipulation for improving lipid yields for biofuel production – with both approaches showing similar yields of triacylglycerides, indicating that more work is required for improving lipid yield and accumulation in algae. Aiming at gaining knowledge of algae genetic manipulation and exploring future use of this information for modifying the lipid biosynthesis pathway, we investigated whether some characteristics of enzymes involved in lipid biosynthesis could relate to lipid yield and accumulation in algae. We made an in silico analysis of amino acid sequence of enzymatic domains and modeled tertiary structure of three proteins involved in the biosynthesis of lipids in microalgae: acetyl‐CoA carboxylase, Acyl‐CoA: diacylglycerol acyltransferase, and glycerol‐3‐phosphate acyltransferase. Our results suggest that, based on primary amino acid sequences and tertiary structure of proteins shared by certain algae, it is likely that these proteins may relate to lipid yield and accumulation, which makes bioinformatics a powerful tool for in silico study of proteins and for selecting genes involved in lipid biosynthesis that could be useful for heterologous transformation in algae with the long term objective of improving their yield, accumulation, and fatty acid composition by genetic engineering.

Several of the over 200 known species of Agave L. are currently used for production of distilled beverages and biopolymers. The plants live in a wide range of stressful environments as a result of their resistance to abiotic stress (drought, salinity, and extreme temperature) and pathogens, which gives the genus potential for germplasm conservation and biotechnological applications that may minimize economic losses as a result of the global climate change. However, the limited knowledge in the genus of genome structure and organization hampers development of potential improved biotechnological applications by means of genetic manipulation and biocatalysis. We reviewed Agave and plant sequences in the GenBank NCBI database for identifying genes with biotechnological potential for fermentation, bioenergy, fiber improvement, and in vivo plant biopolymer production. Three-dimensional modeling of enzyme structures in plant accessions revealed structural differences in sucrose 1-fructosyltransferase, fructan 1-fructosyltransferase, fructan exohydrolase (1-FEH), cellulose synthase (CES), and glucanases (EGases) with possible effects in fructan, sugar, and biopolymer production. Although the coding genes of FEH and enzymes involved in biopolymer production (CES, sucrose synthase, and EGases) remain unidentified in Agave L., our results could aid isolation of such genes in Agave. By comparing nucleotide and amino acid sequences in accessions of Agave and other plants, knowledge may be gained about transcriptional regulation and enzymatic activity factors. Future study is needed of biotechnological application of Agave genes for crop breeding aided by genetic engineering and biocatalysis.