Microalgae a Powerful Source of By-Products. Industrial, Commercial, and Circular Economy Implications.

Since the early 20th century, microalgae have been of interest to researchers worldwide because of their involvement in the ecosystem and their widespread distribution throughout the earth. Their influential role in nature has become increasingly clear, especially in the second part of the last century. Microalgae have a biochemical composition of high commercial interest based mainly on proteins, carbohydrates, lipids, and pigments. Their capacity for autotrophic, heterotrophic, and mixotrophic growth makes microalgae microorganisms of high commercial value with the capacity to produce biomass with a wide range of applications in the chemical, pharmaceutical, biotechnological, food, aquaculture, etc. industries. They are even capable of solving environmental problems at the level of urban and industrial wastewater treatment with biomass that can be transformed into biofuels that ultimately allow sustainable energy to be achieved. Not forgetting the ability of microalgae to capture atmospheric and industrial carbon dioxide and their impact on reducing or halting climate change.

The potential of microorganisms such as bacteria, fungi, and yeasts has been sufficiently explored and exploited by the scientific community as well as at industrial level, however, the same is not true for microalgae. The field of microalgal biotechnology is still undiscovered and there is still a lot of work to be done by the scientific community and industry in general. Today, given the clear signs of climate change, the reduction/limitation of natural resources in raw materials to maintain the full functioning of the industry in general. The large volumes of urban and industrial wastewater generated daily have led to changing strategies to respond to all these challenges based on the circular economy and the production of clean and sustainable energy.

Intensive microalgae cultivation can offer solutions to many real challenges at the food level in general terms, at the energy level as a clean and sustainable source, reduction of atmospheric carbon dioxide through its capture and transformation into chemical energy, bioremediation of wastewater, production of high added value products such as bio-stimulants, biofertilizers, biopolymers, etc. through the development of a real biorefinery based on the use of microalgae biomass. This technological advance must be supported by scientific works to take firmer steps in the transformation towards a circular economy that allows the stop/reduction of climate change.

This research topic is multidisciplinary in nature and aims to publish research articles, reviews, and short communications on the latest advances in microalgae biotechnology in general, the incorporation of intensive microalgae cultures to hybrid processes based on physiochemical and biological processes to cover the wide range of applications of microalgae. As an example, this topic is interested in receiving papers on,

 Intensive cultures of microalgae with industrial application.

 Bioengineering of microalgae and solutions to bottlenecks in photobioreactor design.

 Industrial and urban wastewater treatment based on combined processes with integration of microalgae cultures.

 Algal biomass separation and fractionation operations and their transformation.

 Microalgae as a nutrient in aquaculture feed.

 Biorefinery of microalgae, and production of bio-stimulants, fertilizers, biopolymers, biocides, etc.

 Microalgae as an essential element in cosmetic design.

 Energy production based on microalgae biomass.

 Atmospheric and industrial carbon dioxide capture by microalgae, and removal yields.

 Microalgae and current legislation, limitations, and possible modifications to facilitate the integration of microalgae in industrial processes.

 Etc.

Finally, it should be noted that these examples are for authors' guidance only and in no case are exclusive.