Untapping the potential of algae for β-glucan production: A review of biological properties, strategies for enhanced production and future perspectives

β-Glucan, a naturally occurring polymer of glucose, is found in bacteria, algae, fungi, and higher plants (barley, oats, cereal seeds). Recently, β-glucan has gained attention due to its multiple biological roles, like anticancer, anti-inflammatory, and immunomodulatory effects. Globally, bacteria, mushrooms, yeast and cereals are used as conventional sources of β-glucan. However, obtaining it from these sources is challenging due to low quantity, complex branched structure, and costly extraction process. Algae have emerged as a potential sustainable alternative source of β-glucan to conventional sources due to several advantages including unique structural and functional advantages, higher yields, faster growth rates, and large-scale production in a controlled environment. Additionally, extracting β-glucan from microalgal sources is relatively easy and can be done without altering the structure of β-glucan. Some algal species, such as Euglena spp., are reported to contain higher β-glucan content than conventional β-glucan sources. This review highlights the current research and opportunities associated with algae-derived β-glucan and their biological roles. The challenges, research gaps and strategies to enhance algae-based β-glucan production and the need for further research in this promising area are also discussed. Future research can be extended to comprehend the cellular and molecular mechanisms via which β-glucan functions.