Worldwide Research Trends on Microalgae and Recent Work in Cytologia

Abstract

The latest issue of Cytologia (Vol. 85, Issue 2) includes a regular paper on the long-awaited karyotype analysis of the primitive red alga, Cyanidioschyzon merolae 10D, by Kuroiwa et al. (2020) and a technical note by Miyagishima and Fujiwara (2020) introducing a method to induce a controllable gene expression system in C. merolae. In recent years, Cytologia has focused on introducing the latest research on microalgae and has published excellent papers, such as the two mentioned above. An analysis of worldwide trends in microalgae research based on a bibliometric study found that the number of published papers has increased exponentially since 1990 and 2008. The most relevant journals in this field are Bioresource Technology and Algal Research. Similarly, the number of papers in Cytologia is increasing steadily. Much interest is focused on Chlorella and Chlamydomonas. The major keywords appearing in more than 1,000 articles are those related to microalgae culture, such as biomass, biofuels, lipids, and their applications, or methodologies such as bioreactor. Today, microalgae are attracting attention (i) as sources of high-value compounds such as carotenoids, polyunsaturated fatty acids and phycobiliproteins, (ii) as whole biomass used as ingredients for food and feed, (iii) as extracts or processed biomass to produce biofuel and biofertilizers, and (iv) for bioremediation to ameliorate wastewater, soil, and polluted smoke. In this paper, we focus on how algae and microalgae are treated in Cytologia.

Natural and Artificial Photosymbiosis in Vertebrates

“…Diverse phototrophic algae support the Earthʼs ecosystems (Hosokawa and Kawano 2020, Kuroiwa et al 2020, Miyagishima and Fujiwara 2020, Yoshida et al 2020, Takeshita et al 2021). Among them, some algae live symbiotically in heterotrophic hosts where they undertake photosynthesis (Decelle et al 2019, Uwizeye et al 2021.…”

Nucleomorph: A Fascinating Remnant of Endosymbiosis

“…Algae play an important biological role as producers of organic matter through photosynthesis and have attracted much attention as the organisms responsible for the most efficient production of biomass on earth (Hosokawa and Kawano 2020, Kuroiwa et al 2020, Miyagishima and Fujiwara 2020, Yoshida et al 2020, Takeshita et al 2021, Kinoshita et al 2022, Ota et al 2022. Algae originally emerged through evolutionary endosymbiosis; furthermore, some algae exist that emerged through a secondary endosymbiotic event.…”

A Photosynthetic Animal: A Sacoglossan Sea Slug that Steals Chloroplasts

“…Research on algae has rapidly diversified into various fields, including cell biology (Mine et al 2018, Takano et al 2018, Miyamura et al 2019, Kuroiwa et al 2020, Yoshida et al 2020, molecular biology (Uchida et al 2018, Ota et al 2019, Miyagishima and Fujiwara 2020, and biotechnology (Hayashi et al 2018). Recent products derived from algae include bioethanol and so-called functional foods (Hosokawa and Kawano 2020). Heterotrophic protists and some animals have symbiotic relationships with unicellular alga or cyanobacteria (Venn et al 2008).…”