Effective lipid extraction from undewatered microalgae liquid using subcritical dimethyl ether

Enhancing Biomass and Lipid Production in Messastrum gracile Using Inorganic Carbon Substrates and Alternative Solvents for Lipid Extraction

Microalgae show promise as a biomass and bioproduct for applications in various industries. The cultivation of microalgae plays a crucial role in optimizing biomass yield and bioproduct accumulation. The provision of inorganic carbon substrates substantially enhances microalgal growth and lipid biosynthesis, resulting in marked increases in the production of biofuels and other bioproducts. This study examined biomass and lipid accumulation in Messastrum gracile IFRPD 1061 under inorganic stress conditions, previously unreported. M. gracile IFRPD 1061 was subjected to varying conditions of inorganic carbon substrates, 1-3 g·L-1 sodium carbonate and bicarbonate concentration, to enhance biomass and lipid accumulation. Optimal productivity levels were observed with sodium bicarbonate addition of 3 g·L-1 and 1 g·L-1 for biomass and lipids, resulting in productivities of 392.64 and 53.57 mg·L-1·d-1, respectively. Results underlined the effectiveness of sodium carbonate and bicarbonate as inorganic carbon sources for stimulating microalgal growth and enhancing the production of high-value products. The extraction of lipids from freeze-dried biomass of M. gracile IFRPD 1061 demonstrated optimal yield using methanol/hexane solvents compared with the control experiments. Lipid extraction yields using methanol/hexane were 42.18% and 46.81% from oven-dried and freeze-dried biomass, respectively. Lipids extracted from oven-dried M. gracile IFRPD 1061 using methanol/hexane/chloroform solvents indicated the potential of methanol/hexane as a solvent for lipid extraction from dry microalgal biomass using an ultrasonic-assisted technique. This study contributes valuable insights into maximizing biofuel and bioproduct production from microalgae, highlighting A. gracilis as a promising candidate for industrial applications.

Extraction and Separation of Natural Products from Microalgae and Other Natural Sources Using Liquefied Dimethyl Ether, a Green Solvent: A Review

Microalgae are a sustainable source for the production of biofuels and bioactive compounds. This review discusses significant research on innovative extraction techniques using dimethyl ether (DME) as a green subcritical fluid. DME, which is characterized by its low boiling point and safety as an organic solvent, exhibits remarkable properties that enable high extraction rates of various active compounds, including lipids and bioactive compounds, from high-water-content microalgae without the need for drying. In this review, the superiority of liquefied DME extraction technology for microalgae over conventional methods is discussed in detail. In addition, we elucidate the extraction mechanism of this technology and address its safety for human health and the environment. This review also covers aspects related to extraction equipment, various applications of different extraction processes, and the estimation and trend analysis of the Hansen solubility parameters. In addition, we anticipate a promising trajectory for the expansion of this technology for the extraction of various resources.

Potential of cyanobacteria in the conversion of wastewater to biofuels

Environmental and energy security has now become a serious global problem, requiring a lot of research to find and implement its cost-effective and environmentally friendly alternatives. The development and use of renewable energy sources is necessary and important in order to avoid the emergence of a global economic crisis. One of the solution to prevent a future crisis caused by energy shortages is to introduce biofuels into the fuel market. Despite the fact that various forms of renewable energy are currently used, the prospects for the production of biofuels from cyanobacteria are quite high due to their unique properties, such as a high lipid content and a suitable fatty acid (FA) composition for the production of biofuels, their suitability for growing open water and the ability to grow on wastewater. The purpose of this article is to provide a comprehensive overview of the potential of cyanobacteria in the conversion of wastewater into biofuels. The article covers comparative data on the accumulation of lipids and the content of fatty acids in various representatives of cyanobacteria and their possibilities in the remediation of wastewater. Various approaches to the extraction of lipids from phototrophic microorganisms that are currently available, their advantages and disadvantages, and the results of the monitoring of the main key points of the development of the technology for converting cyanobacterial biomass into biofuels, with an emphasis on the existing barriers, effects and solutions, are also considered. Further research in this field is required for the successful implementation of this technology on an industrial scale.

Surfactant-Free Decellularization of Porcine Aortic Tissue by Subcritical Dimethyl Ether

Porcine aortic tissue was decellularized by subcritical dimethyl ether (DME) used as an alternative to the surfactant sodium dodecyl sulfate. The process included three steps. For the first step, lipids were extracted from the porcine aorta using subcritical DME at 23 °C with a DME pressure of 0.56 MPa. Next, DME was evaporated from the aorta under atmospheric pressure and temperature. The second step involved DNA fragmentation by DNase, which was primarily identical to the common method. For the third step, similar to the common method, DNA fragments were removed by washing with water and ethanol. After 3 days of DNase treatment, the amount of DNA remaining in the porcine aorta was 40 ng/dry-mg, which was lower than the standard value of 50 ng/mg-dry. Hematoxylin and eosin staining showed that most cell nuclei were removed from the aorta. These results demonstrate that subcritical DME eliminates the need to utilize surfactants.