Micro Algal pigments: An introduction to their biosynthesis, applications and genetic engineering

Algae are an enormous biological group, forming 50% of photosynthetic organisms. In addition to having chlorophyll for the absorption of light photons, algae are rich in red, orange, and yellow carotenoids, which mainly protect cells against harmful radiation and free radicals. Moreover, these organisms have phycobiliproteins (red and blue pigments), which are involved in capturing and passing light energy to chlorophylls during photosynthesis and have a wide range of antioxidant properties. Algae also play a key role in substituting artificial colorants with natural colorants due to the adverse side-effects of chemical colorants, especially since natural colors are commonly used by individuals and various industries. Recently, algal pigments have been widely used in medical, nutraceutical, cosmeceutical, and pharmaceutical industries owing to their antioxidant, antidiabetic, anti-obesity, anti-inflammatory, antiaging, antimalarial, and neuroprotective properties. The growing demand for algal bioproducts highlights the importance of evaluating the trends influential factors in their production. The current review study provided an introduction to algal pigment classification, distribution, function, application, and biological production. In addition, we have discussed crucial biochemical pathways, enzymes, and gene/biotechnological modifications, such as transformation and expression regulation, which noticeably affect the metabolism of their sink and source.