What these organisms are and why they are of interest
Cyanobacteria are photosynthetic microorganisms without a nucleus (prokaryotes). They capture the energy of sunlight and use it to make primary metabolites — the proteins, fats and carbohydrates cells need to live and divide — and secondary metabolites. Secondary metabolites are biologically active compounds that are not essential for survival but help the organism, for example, to compete for its habitat and to defend itself against infections [1].
The ability of cyanobacteria to produce substances with antimicrobial potential, including antimicrobial peptides, is being studied as a possible source of new antibiotics against multidrug-resistant microorganisms [2]. Cyanobacteria and microalgae are also considered as a raw material for food, feed additives, chemicals, biofuels and pharmaceutical substances: carotene, astaxanthin, polyunsaturated fatty acids — docosahexaenoic (DHA) and eicosapentaenoic (EPA) — and polysaccharides such as glucans [3].
Microalgae — single-celled algae with a nucleus — are also of interest for "green" technologies. Different species grown under different conditions yield biopolymers: polyhydroxybutyrate, polyurethane, polylactic acid, and polymers based on cellulose, starch and protein. According to the authors of the review, such bioplastics biodegrade, are compatible with living tissue, can be recycled and may be used in agriculture, construction, healthcare, electronics and packaging [4].
Microalgae produce β-glucans, omega-3 fatty acids and antioxidants. Recent reviews consider them a source of ingredients for functional foods, drug delivery systems and synthetic biology [5].