New challenges in microalgae biotechnology

Abstract

Photosynthetic protists, also called microalgae, have been systematically studied for more than a century. However, only recently broad biotechnological applications have fostered a novel wave of research on their potentialities as sustainable resources of renewable energy as well as valuable industrial and agrofood products. At the recent VII European Congress of Protistology held in Seville, three outstanding examples of different research strategies on microalgae with biotechnological implications were presented, which suggested that integrative approaches will produce very significant advances in this field in the next future. In any case, intense research and the application of systems biology and genetic engineering techniques are absolutely essential to reach the full potential of microalgae as cell-factories of bio-based products and, therefore, could contribute significantly to solve the problems of biosustainability and energy shortage.

A Non-Vector Approach to Increase Lipid Levels in the Microalga Planktochlorella nurekis

“…The most promising and widely studied microalgal species are e.g., protein-rich strains used in human nutrition Spirulina (Arthrospira) and Chlorella vulgaris, Dunaliella salina a natural source of β-carotene, Haematococcus pluvialis a producer of astaxanthin for aquaculture feed, Crypthecodinium a producer of long chain polyunsaturated fatty acid (LC-PUFA) docosahexaenoic acid (DHA) and Nannochloropsis a producer of eicosapentaenoic acid (EPA) [1][2][3][4][5][6]. Industrial applications of some microalgal strains may be limited due to a lack of strain robustness or low productivity under outdoor conditions [6,7]. Successful process scale-up in terms of dense biomass concentrations and high biomolecule productivities requires the real-time control and optimization that may be achieved by dynamic modeling [8].…”

“…Successful process scale-up in terms of dense biomass concentrations and high biomolecule productivities requires the real-time control and optimization that may be achieved by dynamic modeling [8]. In order to achieve full processing capabilities of microalgae as cell-factories of bio-based products, several approaches have been considered, e.g., biochemical and genetic engineering [7,[9][10][11][12][13]. Microalgal growth and biomass composition may be modulated by selected environmental factors such as light, temperature and availability of nutrients and minerals [8].…”

“…Indeed, lipid overproduction in numerous microalgal species is achieved by nitrogen depletion [15,16]. As nitrogen depletion-mediated increase in lipid content may be accompanied by reduced growth rate and lipid productivity [16], genetic engineering is also considered to overcome such limitations [7,12]. However, genetic manipulations involve the use of foreign genetic material and construction of genetically modified organisms (GMO) that may raise safety concerns and also require additional regulations in terms of the introduction of GMO microalgae into global food market [17,18].…”

Validation of a New Multicistronic Plasmid for the Efficient and Stable Expression of Transgenes in Microalgae

“…Currently, only high added value compounds, such as pharmaceuticals, cosmetics, or nutraceuticals, are produced from microalgae at industrial scale [1]. In other fields, competition with synthetic products or with those obtained from other sources makes the production of microalgal-based compounds non-viable from the economical point of view [2][3][4][5][6]. As a consequence, more attention is being paid to the genetic engineering of microalgae as a potential tool to achieve economically feasible production of bulk materials and to enhance the productivity of the high added value ones [7][8][9].…”

Microalgae biorefineries: applications and emerging technologies

“…Proposed microalgae cultivation and utilization process including a number of products that could be obtained under the concept of biorefinery. Source: Adapted from [17][18][19] Considering the state of the art of microalgae technology and today oil prices, algae cannot currently be a considered representative alternative for fossil fuels in the near future [21]. One of the most relevant bottlenecks is the high cost of infrastructure investment and downstream operations such as concentration, dehydration, transformation and purification.…”