Microalgal culture preservation: Progress, trends and future developments

There remains a wide variety of microalgae yet to be preserved successfully. The preservation of the viability, genetic integrity, and functional characteristics of microalgae is not only important to the research community as model organisms in genetic modification and taxonomic studies for the classification of novel strains but also in driving developments of circular economy-based biotechnology and biomedical industries. This state-of-the-art review in combination with bibliometric analysis for comprehensive data mining, refinement and analysis; was conducted to reveal trends in microalgae preservation to identify key research areas for the advancement of future microalgae preservation. It was observed that technological advancements differentially evolved the development of lyophilization, cryopreservation, and pre-treatment processes like vitrification. Among all, cryopreservation is the most popular method offering a compromise between accessibility, complexity, and functionality. However, smaller and fund-limited labs may not necessarily have access to cryopreservation facilities thus calling for alternative management-based solutions. Evidence-based past studies are critically discussed in this review and improvements in the following areas were recommended i.e., advanced tools to accurately measure preservation effectiveness and targeted co-development of protocols for the management of valuable resources through concerted efforts among laboratories, biobanks and industries. All this can be accelerated through the sharing of information, tools and resources.