Potential application of Spirulinain dermatology.

Spirulinais an edible cyanobacterium known worldwide for its high nutritional value, and the interest in its biological activity and bioactive compounds, such as pigments, phenolics, peptides, and lipids, has been increasing. Due to the variety of its properties, the potential application of Spirulina in health is wide, including dermatological area. In a context of increasing demand for natural products and actives in cosmetics, this microorganism becomes a great source. This article aims to review what has already been reported in literature about the potential effects of Spirulina or its isolated compounds in skin, for either aesthetic or clinical purposes. In many studies, Spirulina and its components show a good influence in proliferation of dermal fibroblasts and keratinocytes, extracellular matrix, and collagen production, as well as exerting antioxidant and anti-inflammatory action. Thus, they promote a healthy environment for skin's cells and structure, cooperating for the highlighted anti-aging, photoprotection, and wound-healing effects. Some compounds of the cyanobacterium also exert a lighting property through tyrosinase inhibition. Its antimicrobial action can also be advantageous to skin contributing to anti-acne, antibiofilm, and anti-herpes effects. In face of many attributes and due to its rich composition, Spirulina presents multi-benefits and shows an improvement in the general aspect of skin. However, some applications are still in need of studying and more clinical evidence is necessary.

Sustainability of sugarcane lignocellulosic biomass pretreatment for the production of bioethanol.

The sustainability of a biofuel is severely affected by the technological route of its production. Chemical pretreatment can be considered the traditional method of decomposition of the lignocellulose into its mono and oligomeric units, which can be further bioconverted to ethanol. The evaluation of the recent advances in chemical pretreatments of sugarcane bagasse, especially diluted acids, alkaline, organosolv and ionic liquids, identified the critical points for sustainability. In this context, chemicals recovery and reutilization or their substitution by green solvents, heat and electricity generation through bioenergy, reutilization of water from evaporators, vinasse concentration and the upgrading of lignin were discussed as strategic routes for developing sustainable chemical-based lignocellulose pretreatment. The advances in the technologies that allow greater fractionation of lignocellulosic biomass should be focused on the minimization of the use of natural resources, effluent generation and energy expenditure.

Microalgal biorefineries: Integrated use of liquid and gaseous effluents from bioethanol industry for efficient biomass production.

A new method for CO2 recovery was proposed for cultivation of different microalgae. First, a chemical fixation, where CO2 was injected in alkalinized vinasse to form (bi)carbonate salts, was performed. In addition, biological fixation with CO2-enriched air injection was also accomplished for evaluation of the most promising results. Two bioreactor systems, a stirred-tank reactor and a bubble column reactor, were employed. A higher carbon transfer rate (43.35 g.L-1.h-1) was achieved in the bubble column reactor using NaOH-alkalinized vinasse, along with reductions of the chemical oxygen demand (COD), biological oxygen demand (BOD) and turbidity (TD). This allowed the cultivation of microalgae and cyanobacteria at vinasse concentrations between 70 and 100%, reaching a biomass production of 2.25 g.L-1 in 15 days of culture. The viability of chemical CO2 fixation together with the use of 100% treated vinasse from a bioethanol production unit for microalgae cultivation has been demonstrated in a successfully integrated biorefinery approach.