Biotechnological exploitation of microalgae

Abstract

Microalgae are a diverse group of single-cell photosynthetic organisms that include cyanobacteria and a wide range of eukaryotic algae. A number of microalgae contain high-value compounds such as oils, colorants, and polysaccharides, which are used by the food additive, oil, and cosmetic industries, among others. They offer the potential for rapid growth under photoautotrophic conditions, and they can grow in a wide range of habitats. More recently, the development of genetic tools means that a number of species can be transformed and hence used as cell factories for the production of high-value chemicals or recombinant proteins. In this article, we review exploitation use of microalgae with a special emphasis on genetic engineering approaches to develop cell factories, and the use of synthetic ecology approaches to maximize productivity. We discuss the success stories in these areas, the hurdles that need to be overcome, and the potential for expanding the industry in general.

Microalgae Cultivation on Anaerobic Digestate of Municipal Wastewater, Sewage Sludge and Agro-Waste

“…Microalgae are unicellular photosynthetic organisms; from an industrial and economic perspective, their cultivation has a great deal of potential [1,2]. Indeed, several valuable products may be obtained from their biomass, ranging from animal and human nutrition, cosmetics and pharmaceuticals, to biofuels such as biodiesel, biogas and hydrogen [3,4,5,6,7,8,9,10].…”

Two Glycerol-3-Phosphate Dehydrogenases from Chlamydomonas Have Distinct Roles in Lipid Metabolism

“…For example, saline stress often induces the accumulation of glycerol for osmotic adjustment (Ben-Amotz et al, 1982), while nutrient starvation leads to large induction of carbon storage metabolism, including the accumulation of storage lipids, principally triacylglycerol (TAG), and the storage carbohydrate starch (Siaut et al, 2011;Schmollinger et al, 2014;Bajhaiya et al, 2016a). There is also interest in the use of microalgal metabolites as industrial products, such as a feedstock for biofuels or for nutraceutical application (Driver et al, 2014;Gangl et al, 2015;Bajhaiya et al, 2017). However, in order to achieve this biotechnological potential of microalgae, improved understanding of algal metabolism and the identification of potential targets for metabolic engineering are needed.…”

Efficient targeting of recombinant proteins to the thylakoid lumen in Chlamydomonas reinhardtii using a bacterial Tat signal peptide

“…A number of heterologous 42 proteins have been expressed, including vaccines, antibody fragments and terpene 43 synthesis enzymes [for recent reviews see [1][2][3]. Tools for the genetic engineering of 44 this green microalga have advanced remarkably, and it is now possible to transform 45 both the nuclear and chloroplast genomes with reasonable efficiency.…”