Haematococcus pluvialis: A potential feedstock for multiple-product biorefining

The microalga Haematococcus pluvialis synthesizes high quantities of the antioxidant astaxanthin under adverse growth conditions. In addition to astaxanthin, the species accumulates other metabolites with commercial value including lipids, carbohydrates, and proteins. These compounds can be utilized to produce biodiesel, bioethanol, biogas, biofertilizer and animal feed among others. Despite the high biotechnological potential of H. pluvialis, the high costs associated with the production process make the commercial realization of microalgae-based bioproducts challenging. As a solution, biorefining of H. pluvialis can be carried out through the integration of diverse production processes within a single production facility, aiming to produce numerous compounds from the same feedstock which in turn reduces the consumption of raw materials, energy, and freshwater. In addition, biorefining allows the maximum utilization of the feedstock, minimizing waste generation and improving the sustainability of the process while promoting the concept of a circular bioeconomy. Thus, the present review aims to discuss the biorefining potential of H. pluvialis in view of implementing more sustainable and cleaner production technologies. In contrast to existing reviews, the present review analyzes the potential of utilizing the particular microalgae species to generate multiple products without being constricted to astaxanthin. Moreover, the current status of related research, potential challenges, and solutions are provided along with future perspectives in the research domain.