The complete chloroplast genome of an edaphic oleaginous microalga Vischeria stellata SAG 33.83 (Eustigmatophyceae)

Bioprospecting of microalgae metabolites against cytokine storm syndrome during COVID-19

In viral respiratory infections, disrupted pathophysiological outcomes have been attributed to hyper-activated and unresolved inflammation responses of the immune system. Integration between available drugs and natural therapeutics have reported benefits in relieving inflammation-related physiological outcomes and microalgae may be a feasible source from which to draw from against future coronavirus-infections. Microalgae represent a large and diverse source of chemically functional compounds such as carotenoids and lipids that possess various bioactivities, including anti-inflammatory properties. Therefore in this paper, some implicated pathways causing inflammation in viral respiratory infections are discussed and juxtaposed along with available research done on several microalgal metabolites. Additionally, the therapeutic properties of some known anti-inflammatory, antioxidant and immunomodulating compounds sourced from microalgae are reported for added clarity.

Monodopsis and Vischeria Genomes Shed New Light on the Biology of Eustigmatophyte Algae

Members of eustigmatophyte algae, especially Nannochloropsis and Microchloropsis, have been tapped for biofuel production owing to their exceptionally high lipid content. Although extensive genomic, transcriptomic, and synthetic biology toolkits have been made available for Nannochloropsis and Microchloropsis, very little is known about other eustigmatophytes. Here we present three near-chromosomal and gapless genome assemblies of Monodopsis strains C73 and C141 (60 Mb) and Vischeria strain C74 (106 Mb), which are the sister groups to Nannochloropsis and Microchloropsis in the order Eustigmatales. These genomes contain unusually high percentages of simple repeats, ranging from 12% to 21% of the total assembly size. Unlike Nannochloropsis and Microchloropsis, long interspersed nuclear element repeats are abundant in Monodopsis and Vischeria and might constitute the centromeric regions. We found that both mevalonate and nonmevalonate pathways for terpenoid biosynthesis are present in Monodopsis and Vischeria, which is different from Nannochloropsis and Microchloropsis that have only the latter. Our analysis further revealed extensive spliced leader trans-splicing in Monodopsis and Vischeria at 36-61% of genes. Altogether, the high-quality genomes of Monodopsis and Vischeria not only serve as the much-needed outgroups to advance Nannochloropsis and Microchloropsis research, but also shed new light on the biology and evolution of eustigmatophyte algae.