Suchergebnisse

The incredible increase in world population, which could reach nine billion by 2050, and the rapid progress of globalization in recent decades have put pressure on the food and energy sectors. The resources currently available for energy production are insufficient to meet future demand. These facts are pushing governments and scientific organizations all over the world to search for alternative renewable energy sources. Microalgae present an ideal, resurgent resource for the production of biofuels, especially biodiesel and biogas, because their lipid productivity is greater than that of other terrestrial food crops. However, from a biotechnological point of view, the use of microalgae requires further investigation and development to be economically viable, particularly in regard to cost and biomass production. The most important step in the use of microalgae for biofuel production is strain selection. The optimal strain must be able to withstand outdoor conditions and survive seasonality. Four related manuscripts were prepared during my Ph.D. project. Two of them have been published, one has been submitted for publication, and the fourth is ready for submission. Together, they focus on new strategies for strain selection, lipid production increase, lipid vesicles detection and imaging, total cost reduction strategies, biodiesel production from promising strains, and biogas production from the remaining microalgal residues. From a practical perspective, only a few microalgal species have been investigated for pharmaceutical and industrial applications. Throughout my Ph.D. project, I have identified microalgal strains able to grow at high temperature and under light stress, as a step toward the development of sustainable microalgal fuels. The four manuscripts that have resulted from my project are described below. In the first manuscript, entitled "Isolation and characterization of thermo-tolerant Egyptian marine microalgae as proposed candidates for biodiesel prod

This Brief provides a concise review of the potential use of microalgae for biofuel production. The following topics are highlighted: the advantages of microalgae over conventional biofuel-producing crops; technological processes for energy production using microalgae; microalgal biomass production systems, production rates and costs; algae cultivation strategies and main culture parameters; biomass harvesting technologies and cell disruption; CO2 sequestration; life cycle analysis; and algal biorefinery strategies. The conclusions section discusses the contribution of the technologies described to environmental sustainability and future prospects.

Microcystins have been the subject of increasingly alarming popular and scientific articles, which have taken as their unquestionable foundation the provisional Guideline of 1 μg/L established by the WHO Panel on microcystins levels in water, and mechanically translated by the Oregon government as 1 μg/g of Klamath Aphanizomenon flos aquae microalgae. This article underlines the significant limitations and ultimately scientific untenability of the WHO Guideline on microcystins in water, for being based on testing methodologies which may lead to a significant overestimation of the toxicity of microcystins. I propose criteria for the realization of new experimental studies on the toxicity of microcystins, based on the essential understanding that drinking water is contaminated by whole cyanobacterial microalgae rather than purified microcystins, while it is important to differentiate between water and cyanobacterial supplements. It is indeed a mistake to automatically apply standards that are proper for water to cyanobacterial supplements, as they have different concentrations of the antioxidant substances that inactivate or significantly reduce the toxicity of microcystins, a fact that also require that each cyanobacterial supplement be tested individually and through realistic testing methodologies.

Microalgae have an outstanding capacity to efficiently produce value-added compounds. They have been inspiring researchers worldwide to develop a blue biorefinery, supporting the development of the bioeconomy, tackling the environmental crisis, and mitigating the depletion of natural resources. In this review, the characteristics of the carotenoids produced by microalgae are presented and the downstream processes developed to recover and purify them are analyzed, considering their main applications. The ongoing activities and initiatives taking place in Portugal regarding not only research, but also industrialization under the blue biorefinery concept are also discussed. The situation reported here shows that new techniques must be developed to make microalgae production more competitive. Downstream pigment purification technologies must be developed as they may have a considerable impact on the economic viability of the process. Government incentives are needed to encourage a constructive interaction between academics and businesses in order to develop a biorefinery that focuses on high-grade chemicals.

Several microalgae species have been exploited due to their great biotechnological potential for the production of a range of biomolecules that can be applied in a large variety of industrial sectors. However, the major challenge of biotechnological processes is to make them economically viable, through the production of commercially valuable compounds. Most of these compounds are accumulated inside the cells, requiring efficient technologies for their extraction, recovery and purification. Recent improvements approaching physicochemical treatments (e.g., supercritical fluid extraction, ultrasound-assisted extraction, pulsed electric fields, among others) and processes without solvents are seeking to establish sustainable and scalable technologies to obtain target products from microalgae with high efficiency and purity. This article reviews the currently available approaches reported in literature, highlighting some examples covering recent granted patents for the microalgae's components extraction, recovery and purification, at small and large scales, in accordance with the worldwide trend of transition to bio-based products. ; This work was financially supported by Base Funding—UIDB/00511/2020 of Laboratory for Process Engineering, Environment, Biotechnology and Energy—LEPABE—funded by National funds through the FCT/MCTES (PIDDAC); Base Funding—UIDB/04730/2020 of Center for Innovation in Engineering and Industrial Technology, CIETI—funded by national funds through the FCT/MCTES (PIDDAC); project IF/01093/2014/CP1249/CT0003 funded by national funds through FCT/MCTES; project "EXTRATOTECA—Microalgae Extracts for High Value Products"—POCI-01-0247-FEDER-033784, funded by FEDER funds through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES. António Martins thanks FCT (Fundação para a Ciência e Tecnologia) for funding through program DL 57/2016—Norma transitória. Wilson Júnior thanks European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement number 867473. ; info:eu-repo/semantics/publishedVersion

Can we produce new medicines from microalgae?
Inflammatory bowel disease (IBD) is a chronic inflammation in the digestive tract. Currently no effective treatment exists, something that the researchers of the EU-funded Algae4IBD project want to change with the help of microalgae. Microalgae are a promising resource for new medical agents, and algae cultivation can be optimised to produce the desired compounds in the required quantities. How does it all work? Two scientists involved in the Algae4IBD project give an insight.

This paper contributes to the implementation of the objectives of the SCOR and IOC/UNESCO GlobalHAB Program (www.globalhab.info) on Benthic HABs and on Climate Change.-- 27 pages, 5 figures, 2 tables ; Sea surface temperatures in the world's oceans are projected to warm by 0.4–1.4 °C by mid twenty-first century causing many tropical and sub-tropical harmful dinoflagellate genera like Gambierdiscus, Fukuyoa and Ostreopsis (benthic harmful algal bloom species, BHABs) to exhibit higher growth rates over much of their current geographic range, resulting in higher population densities. The primary exception to this trend will be in the tropics where temperatures exceed species-specific upper thermal tolerances (30–31 °C) beyond which growth slows significantly. As surface waters warm, migration to deeper habitats is expected to provide refuge. Range extensions of several degrees of latitude also are anticipated, but only where species-specific habitat requirements can be met (e.g., temperature, suitable substrate, low turbulence, light, salinity, pH). The current understanding of habitat requirements that determine species distributions are reviewed to provide fuller understanding of how individual species will respond to climate change from the present to 2055 while addressing the paucity of information on environmental factors controlling small-scale distribution in localized habitats. Based on the available information, we hypothesized how complex environmental interactions can influence abundance and potential range extensions of BHAB species in different biogeographic regions and identify sentinel sites appropriate for long-term monitoring programs to detect range extensions and reduce human health risks ; EB is supported by project CoCliME an ERA4CS Network (ERA-NET) initiated by JPI Climate, and funded by EPA (IE), ANR (FR), BMBF (DE), UEFISCDI (RO), RCN (NO) and FORMAS (SE), with co-funding by the European Union (Grant No. 690462). Program funds from the National Centers for Coastal Ocean Science, NOAA supported RWL. Ocean Tester, LLC provided support for PAT.[CG]