Etiele Greque de Morais

Biologically Active Metabolites Synthesized by Microalgae

Microalgae are microorganisms that have different morphological, physiological, and genetic traits that confer the ability to produce different biologically active metabolites. Microalgal biotechnology has become a subject of study for various fields, due to the varied bioproducts that can be obtained from these microorganisms. When microalgal cultivation processes are better understood, microalgae can become an environmentally friendly and economically viable source of compounds of interest, because production can be optimized in a controlled culture. The bioactive compounds derived from microalgae have anti-inflammatory, antimicrobial, and antioxidant activities, among others. Furthermore, these microorganisms have the ability to promote health and reduce the risk of the development of degenerative diseases. In this context, the aim of this review is to discuss bioactive metabolites produced by microalgae for possible applications in the life sciences.

Biological effects of Spirulina (Arthrospira) biopolymers and biomass in the development of nanostructured scaffolds.

Spirulina is produced from pure cultures of the photosynthetic prokaryotic cyanobacteria Arthrospira. For many years research centers throughout the world have studied its application in various scientific fields, especially in foods and medicine. The biomass produced from Spirulina cultivation contains a variety of biocompounds, including biopeptides, biopolymers, carbohydrates, essential fatty acids, minerals, oligoelements, and sterols. Some of these compounds are bioactive and have anti-inflammatory, antibacterial, antioxidant, and antifungal properties. These compounds can be used in tissue engineering, the interdisciplinary field that combines techniques from cell science, engineering, and materials science and which has grown in importance over the past few decades. Spirulina biomass can be used to produce polyhydroxyalkanoates (PHAs), biopolymers that can substitute synthetic polymers in the construction of engineered extracellular matrices (scaffolds) for use in tissue cultures or bioactive molecule construction. This review describes the development of nanostructured scaffolds based on biopolymers extracted from microalgae and biomass from Spirulina production. These scaffolds have the potential to encourage cell growth while reducing the risk of organ or tissue rejection.

Biological CO2 mitigation from coal power plant by Chlorella fusca and Spirulina sp.

CO2 biofixation by microalgae and cyanobacteria is an environmentally sustainable way to mitigate coal burn gas emissions. In this work the microalga Chlorella fusca LEB 111 and the cyanobacteria Spirulina sp. LEB 18 were cultivated using CO2 from coal flue gas as a carbon source. The intermittent flue gas injection in the cultures enable the cells growth and CO2 biofixation by these microorganisms. The Chlorella fusca isolated from a coal power plant could fix 2.6 times more CO2 than Spirulina sp. The maximum daily CO2 from coal flue gas biofixation was obtained with Chlorella fusca (360.12±0.27mgL-1d-1), showing a specific growth rate of 0.17±<0.01d-1. The results demonstrated the Chlorella fusca LEB 111 and Spirulina sp. LEB 18 potential to fix CO2 from coal flue gas, and sequential biomass production with different biotechnological destinations.

Biodiesel and Bioethanol from Microalgae

Microalgae are a group of unicellular or multicellular photosynthetic microorganisms that have the ability to use sources of organic and inorganic carbon for their development. Microalgal biomass has been proposed as a raw material for the production of energy and other products due to its high productivity, flexibility, capacity for using wastewater, and the fact that nonfertile land is required for cultivation. These microorganisms can synthesize and store lipids in the form of triacylglycerols and fermentable carbohydrates, which are used for the production of biodiesel and bioethanol, respectively. The application of nutrient-rich industrial effluents for the cultivation and the application of microalgal biomass within the photobiorefinery concept are matters that research groups around the world have considered to reduce production costs and to make sustainable energy production using these microorganisms feasible.

Electrospun Polymeric Nanofibers in Food Packaging

Abstract The application of nanotechnology can improve the physical, chemical, and biological properties of materials by reducing their particle size and increasing their contact surface area and reactivity. One of the most active areas of nanoscience research and development is food packaging. The use of nanostructured materials, such as nanofibers in food packaging can potentiate their functional characteristics. The development of polymeric nanofibers that are capable of improving the barrier and antimicrobial properties of materials is promising. These nanostructures may also be employed in nanosensor development for the detection and monitoring of food conditions during transport and storage. The aim of the chapter is to discuss the application and acquisition of polymeric nanofibers for food packaging development through the electrospining technique.

Cultivation of different microalgae with pentose as carbon source and the effects on the carbohydrate content

ABSTRACT In the search for alternative carbon sources for microalgae cultivation, pentoses can be considered interesting alternatives since the most abundant global source of renewable biomass is lignocellulosic waste, which contains significant quantities of pentoses. However, the use of pentoses (C5) in the cultivation of microalgae is still not widely studied and only recently the first metabolic pathway for pentose absorption in microalgae was proposed. So, the objective of this work was to evaluate if the use of pentoses affects the growth and carbohydrates content of Chlorella minutissima, Chlorella vulgaris, Chlorella homosphaera and Dunaliella salina. The kinetic parameters, carbohydrate and protein content and the theoretical potential for ethanol production were estimated for all strains. The highest cellular concentrations (1.25 g L−1) were obtained for D. salina with 5% of pentoses. The addition of pentoses leads to high levels of carbohydrates for C. minutissima (58.6%) cultured with 5% of pentoses, and from this biomass, it is possible to determine a theoretical production of ethanol of 38 mL per 100 g of biomass. The pentoses affect the growth and the biomass composition of the studied strains, generating biomass with potential use for bioethanol production.