High-resolution melting analysis for identification of microalgae species

There is great microalgae biodiversity and their rediscovery as an inexhaustible source of biotechnological resources for all types of applications is leading to the already demonstrated benefits of their bioactive compounds which has boosted their industrial development. For this development, it is essential to have available technologies to easily control large-scale cultures. In this study, a high-resolution melting (HRM) analysis was developed to identify different microalgae that are currently used by the industry. HRM analysis is a simple, economical, fast, and reproducible method that allows the use of a stable molecule such as DNA to track a culture day by day without the need for visual microscopic controls. Ten microalgae were characterized by qPCR-HRM analysis: Isochrysis galbana, Phaeodactylum tricornutum, Muriellopsis sp., Porphyridium cruentum, Botryococcus braunii, Nannochloropsis gaditana, Chlorella sorokiniana, Chlamydomonas reinhardtii, Haematococcus pluvialis, and Scenedesmus obliquus. We determined that through the use of primers designed specifically for the 18S rDNA ribosomal gene, it is possible to significantly discriminate among the ten strains simultaneously by using HRM analysis. The results are also replicable over time, facilitating the daily and low-cost control of species used in the biotechnology industry.