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The article discusses a research project using a nonconventional bioprocess for in vitro biomass and oil production of Jatropha curcas, a species that produces nonedible oils. The method used in vitro cell suspension culture techniques to produce Jatropha biomass and oil. The in vitro growing characteristics of several J. curcas varieties were studied and the oil and fatty acid of samples were tested to select the most promising cell line required for biodiesel production.

SUMMARY: Efficient approaches to increase plant lipid production are necessary to meet current industrial demands for this important resource. While Jatropha curcas cell culture can be used for in vitro lipid production, scaling up the system for industrial applications requires an understanding of how growth conditions affect lipid metabolism and yield. Here we present a bottom‐up metabolic reconstruction of J. curcas supported with labeling experiments and biomass characterization under three growth conditions. We show that the metabolic model can accurately predict growth and distribution of fluxes in cell cultures and use these findings to pinpoint energy expenditures that affect lipid biosynthesis and metabolism. In addition, by using constraint‐based modeling approaches we identify network reactions whose joint manipulation optimizes lipid production. The proposed model and computational analyses provide a stepping stone for future rational optimization of other agronomically relevant traits in J. curcas. Significance Statement: We present a bottom‐up metabolic reconstruction for Jatropha curcas cells refined with condition‐specific experimental data. By using constraint‐based modeling approaches the metabolic model provides accurate quantitative and qualitative predictions of growth and of intracellular fluxes in lipid metabolism, respectively. We also identified reactions whose joint manipulation optimizes lipid production without sacrificing biomass, contributing knowledge about the operation of Jatropha lipid pathways and their relation to other metabolism, providing a stepping stone for future rational optimization of other agronomically relevant traits in Jatropha. [ABSTRACT FROM AUTHOR]

In this study the metabolic responses of Botryococcus braunii were analyzed upon different inorganic carbon dosages and nutrient limitation conditions in terms of lipid and biomass productivity, as well as photosynthetic performance. The nutritional schemes evaluated included different levels of sodium bicarbonate and nitrogen and phosphorus starvation, which were contrasted against standard cultures fed with CO2. Bicarbonate was found to be an advantageous carbon source since high dosages caused a significant increase in biomass and lipid productivity, in addition to an enhanced photosynthetic quantum yield and neutral lipids abundance. This contrasts to the commonly used approach of microalgae nutrient limitation, which leads to high lipid accumulation at the expense of impaired cellular growth, causing a decline in overall lipid productivity. The lipidome analysis served to hypothesize about the influence of the nutritional context on B. braunii structural and storage lipid metabolism, besides the adaptive responses exhibited by cells that underwent nutrient stress. [ABSTRACT FROM AUTHOR]

Background: Theobroma cacao is a major source of flavonoids such as catechins and their monomers proanthocyanidins (PAs), widely studied for their potential benefits in cardiovascular diseases. Light has been shown to promote plant secondary metabolite production in vitro. In this study, cacao cells cultured in 7.5 L stirred tank photobioreactors (STPs) were exposed to a change of white to blue LED lights for 28 days (d). Results: Transcriptomic analyses were performed in three time points comparing changing expression patterns, after cell exposure to white light (d0-VS-d14), after a shift from white to blue light (d14-VS-d15), and after an extended period of blue light for the following 15 days (d15-VS-d28). Under white light, there was enrichment in metabolic pathways associated with cell growth (carbon, glycolysis, and amino acid biosynthesis) accompanied by a significant increase in the PAs content. In the shift to blue light, further increase in PAs content was observed concomitantly with the significant expression of TWO-COMPONENT RESPONSE REGULATOR genes involved in the early stress responses via circadian clock and hormone pathways. Under blue light exposure, we observed a depletion of PAs content associated with ROS-mediated stress pathways. Conclusions: Light effects on large-scale cell cultures in photobioreactors are complex and pleiotropic; however, we have been able to identify key regulatory players upstream cacao flavonoid biosynthesis in STPs, including TWO-COMPONENT SYSTEM and ROS-signaling genes. The crosstalk between flavonoid biosynthesis and regulatory networks led to understand the dynamics of flavonoid production and degradation in response to light-driven ROS signals. This can be used to optimize the time, and the yield of in vitro targeted metabolites in large-scale culture systems. [ABSTRACT FROM AUTHOR]

Microalgal biomass has been widely investigated as a source of renewable energy, but currently, some alternatives are not economically competitive. Thermochemical conversion of biomass is an alternative way to transform their organic compounds into liquid and gaseous fuels. The aim of this work is twofold; first, the pyrolytic process of the microalga Botryococcus braunii (BB) by thermogravimetric analysis, as well as the relevant reaction kinetic constants and related activation energies, is assessed. Secondly, a sensitivity analysis of the biomass gasification process with air using a thermochemical model was conducted to predict the composition of a syngas as a function of the biomass moisture content and the biomass/air ratio. The results showed that BB biomass is composed mainly of carbon (62.4 wt.%) with volatile solids of 84 wt.%, while the fixed carbon represents around 7 wt.%. Additionally, observed values for heating (27.86 MJ kg−1) and activation energy (~ 110 kJ mol−1) were different from other algal feedstocks due to the capacity of accumulation of liquid hydrocarbons of this. On the other side, the gasification process showed it was found that the moisture content in the biomass and biomass/air ratio variables are key parameters for reaction temperature and producer gas composition. Accordingly, with a suitable combination of these variables, it is possible to obtain a syngas composed of gaseous species with high energy content (CO, 18 vol.%; H2, 17 vol.%; and CH4, 2 vol.%.), which can be transformed through processes such as Fisher-Tropsch process into liquid biofuels such as kerosene or gasoline. [ABSTRACT FROM AUTHOR]

Abstract The green synthesis of biomaterials is of significant interest as it enables the safe and sustainable preparation of noble metallic nanoparticles for medical applications. Microalgae polysaccharides have received attention due to their outstanding properties such as biocompatibility, biodegradability and low cost. In addition, due to their variety of remarkable biological and physicochemical properties, polysaccharide-based nanoparticles have advantageous features yet to be explored. The primary objective of the current research was to investigate exopolysaccharides isolated from green microalgae Botryococcus braunii (EPBb) and Chlorella pyrenoidosa (EPCp), as both reducing and stabilizing agents, for the green synthesis of silver nanoparticles (AgNPs). Their antibacterial activity towards Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and antibiotic-resistant bacteria (methicillin-resistant Staphylococcus aureus) was studied, as well as their cytotoxicity to human dermal fibroblasts. The presently synthesized AgNPs were spherical in shape and exhibited characteristic surface plasmon resonance at 430 nm. The main population had a particle size which ranged between 5 and 15 nm as analyzed by transmission electron micrographs. Zeta potentials averaged −51.81 ± 3.01 mV using EPBb and −12.16 ± 2.41 mV using EPCp. More importantly, AgNPs possessed strong antibacterial activity in a dose-dependent manner, even against drug-resistant bacteria. The enhanced antibacterial activity of these particles is explained due to extensive reactive oxygen species generation and bacterial cell membrane damage. In contrast, such AgNPs were not cytotoxic at the same therapeutic range to fibroblasts (0.5–10.0 μg/mL). In summary, these results showed that polysaccharide-capped AgNPs have a strong potential for numerous medical applications, such as antibacterial agents in pharmaceutical and biomedical areas. Graphical abstract (A) UV/Vis spectra and TEM micrographs of polysaccharide-capped silver nanoparticles, (B) growth curve and effect on the cell morphology of E. coli treated with the silver nanoparticles. Unlabelled Image Highlights • A new and useful application for exopolysaccharides from microalgae Botryococcus braunii and Chlorella pyrenoidosa. • Green and sustainable approach for the synthesis of silver nanoparticles based on the biorefinery from microalgae is highlighted. • Nanoparticles exhibited antibacterial activity towards Gram-positive, Gram-negative, and antibiotic-resistant bacteria. • The killing mechanisms involved in the observed antibacterial activity were investigated. • The polysaccharide capped‑silver nanoparticles were not cytotoxic to fibroblasts at the same therapeutic range. [ABSTRACT FROM AUTHOR]

In recent years, polyphenols from Theobroma cacao and other plant sources have been widely used as natural chemopreventive agents due to their antioxidant properties. Some studies indicate that the polyphenol content, particularly flavan-3-ols, is strongly correlated to the intensity of the purple color in fresh cocoa seeds. However, no visual marker of polyphenol synthesis has been reported in this plant species. The purposes of this study were to monitor the production of certain flavan-3-ols and methylxanthines by chemical and histological analysis in three ecotypes of cacao grown in Colombia at three developmental stages and to compare the result to a standard of polyphenol production over time for two T. cacao cell lines grown in vitro. According to the observations made, polyphenols are stored exclusively in polyphenolic cells that are randomly located between cells that form cotyledon tissue and their biosynthesis is directly proportional to the seed age. Polyphenols are accumulated in the cytoplasm of this kind of cells, which is moved to the protoplasm, coating the cytoplasmic membrane, possibly due to the growth of the vacuole during maturation. In cell culture, polyphenol accumulation is also associated with a particular cell type that is immersed in a group of non-polyphenolic cells. However, it is only possible to identify these cells using destructive staining techniques, which do not allow application of this separation method for obtaining homogenous cell lines. Despite this finding, in this study, it was possible to identify a macroscopic color marker of populations that are rich in dark beige polyphenols, which could be used to screen cell populations. [ABSTRACT FROM AUTHOR]

Four basidiomycete fungi, Agaricus blazei Murrill (Agaricomycetideae), Ganoderma lucidum (W.Curt.: Fr.) P. Karst., Grifola frondosa (Dicks.: Fr.) S.F. Gray (Higher Basidiomycetes), and Pleurotus pulmonarius (Fr.) Quél. (Agaricomycetideae) were evaluated using three conservation methods for 12 months, recording their viability in order to establish the best conservation method. Growth kinetics, biomass, and polysaccharide production were studied. The conservation methods implemented included: distilled water at 24 °C; sawdust and rice bran with 10% glycerol at -20 °C; sawdust and rice bran with 10% glycerol at -80 °C; and freeze-drying of biomass with trehalose or skimmed milk. After conducting the analysis of the results after 12 months of conservation, we determined that the distilled water treatment at 24 °C was the best conservation method with the highest percentage of recoverability, at 83.3% during the 12th month, followed by the cryoconservation treatment at 80 °C, where 75% were recovered with no negative effects on biomass and polysaccharide production. The -20 °C and freeze-drying treatments were not effective; with cryoconservation at -20 °C treatment, strain recovery only occurred during the first month and with freeze-drying it was not possible to recover any strains during the entire 12-month period evaluated. [ABSTRACT FROM AUTHOR]

Grifola frondosa is a Basidiomycete fungus edible and medicinal, it produces polysaccharides such a glucans (β-1,6 and β-1,3) with anti-tumor and inmuno-stimulating activity. For this work, the aim was evaluate the incidence of different carbon sources (FC) in biomass and exo-polymer (EPS) production, under submerged culture conditions, by using a factorial statistical design with two factors: carbon source (FC(1-7))) and medium (MB and MS). The maximal yield of mycelial biomass (21,10 ± 0,82) gl and the maximal yield in EPS (6,53 ± 0,14) g/l was achieved by using the MB medium supplemented with FC4). Besides, it was possible to develop a medium that fulfills the objective of reducing costs from $18.455 to $656 Colombian pesos for each liter of medium used, which produces ( 14,14 ± 0,82) g/l of biomass and (5,16 ± 0, 14) g/1 of EPS, using the MS medium supplemented with FC4) This result opens new alternatives and possibilities in our country for developing products of this species with cost that can be reached by population. [ABSTRACT FROM AUTHOR]