Article
Green & Sustainable Science & Technology
Yongteng Zhao, Tengsheng Qiao, Dan Gu, Liyan Zhu, Xuya Yu
Summary: The study utilized a joint strategy of salinity stress and chemical induction to improve lipid production; the results demonstrated that the combined application of GABA or CaCl2 and salt stress stimulated biolipid synthesis in microalgae; the quality of algal lipid-derived biodiesel met commercial standards.
Article
Engineering, Chemical
Hao-Cheng Yu, Chyi-How Lay, Peer Mohamed Abdul, Jane-Yii Wu
Summary: This study optimized the cultivation conditions for a local microalgae species, Chlorella sp. G3H3-1-2, with high pH-resistant, high growth rate, and high lipid content. It was found that a pH range of 6.0 to 8.0 with glucose as the carbon source resulted in the highest specific growth rate of 1.22 day(-1) for Chlorella sp. G3H3-1-2. However, the highest total FAMEs content of 59% in the biomass of 1.75 g/L was obtained when using the combination of glucose and (NH4)2SO4 at a high pH value of 10.
Article
Energy & Fuels
Farzaneh Noori, Saeid Vahdat
Summary: This study aimed to evaluate the effect of different environmental shocks on the nutrients concentration in Chlorella sp. The results showed that protein content decreased significantly in all treatments, while lipid content increased significantly in treatments of starvation and high pH. In conclusion, environmental shocks can induce biosynthesis of lipids and fatty acids in Chlorella sp.
BIOENERGY RESEARCH
(2023)
Article
Microbiology
Xiaofang Li, Xinping Yu, Qian Liu, Yong Zhang, Qiuzhen Wang
Summary: A strain of marine oleaginous thraustochytrid, Schizochytrium sp. HBW10, was isolated from a water column in Bohai Bay in Northern China for the first time. The lipid production characteristics of S. sp. HBW10 using food waste hydrolysate with different initial pH values were investigated. The results showed that a higher initial pH promoted the growth and accumulation of saturated fatty acids.
Article
Environmental Sciences
Na Cui, Yongjie Feng, Ximeng He, Hong Gu, Peng Zhao
Summary: For the microalgae Yu, the lipid-rich Heveochlorella sp. Yu with spontaneous flocculation characteristics is suitable for harvest. The polysaccharide composition, ζ potential close to zero, and adhesion free energy related to cell binding all play important roles in the spontaneous flocculation of microalgae.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Multidisciplinary Sciences
Nikhil Seshagiri Rao, Ludwig Lundberg, Shuai Palmkron, Sebastian Hakansson, Bjorn Bergenstahl, Magnus Carlquist
Summary: In the study, multivariate flow cytometry was used to investigate the effects of temperature, initial pH, and oxygen levels on cell growth and size distributions of L. reuteri. It was found that under optimal growth conditions, smaller cells and less heterogeneous populations were observed. Morphological heterogeneities were significant under non-optimal conditions, with factors such as low temperature, high initial pH, and high oxygen levels triggering changes towards cell chain formation.
SCIENTIFIC REPORTS
(2021)
Article
Biotechnology & Applied Microbiology
Shadman Shokravi, Nadia Bahavar
Summary: The study revealed that under extreme alkaline pH conditions, low concentrations of chromium (VI) (0.5 μM) promoted the growth and pigment production of cyanobacteria, while higher concentrations of chromium (VI) had toxic effects, damaging the photosystem and phycobilisome structures. However, long-term recovery was possible. The combination of extreme alkaline pH, different concentrations of Cr(VI), and time could affect cyanobacterial behaviors individually or in combination.
JOURNAL OF APPLIED PHYCOLOGY
(2021)
Article
Microbiology
Ryudo Ohbayashi, Shunsuke Hirooka, Ryo Onuma, Yu Kanesaki, Yuu Hirose, Yusuke Kobayashi, Takayuki Fujiwara, Chikara Furusawa, Shin-ya Miyagishimal
FRONTIERS IN MICROBIOLOGY
(2020)
Article
Ecology
Ryo Onuma, Shunsuke Hirooka, Yu Kanesaki, Takayuki Fujiwara, Hirofumi Yoshikawa, Shin-ya Miyagishima
Article
Multidisciplinary Sciences
Hisayoshi Nozaki, Wuttipong Mahakham, Wirawan Heman, Ryo Matsuzaki, Masanobu Kawachi
Article
Multidisciplinary Sciences
Shunsuke Hirooka, Reiko Tomita, Takayuki Fujiwara, Mio Ohnuma, Haruko Kuroiwa, Tsuneyoshi Kuroiwa, Shin-ya Miyagishima
SCIENTIFIC REPORTS
(2020)
Article
Plant Sciences
Lin Wei Jong, Takayuki Fujiwara, Shunsuke Hirooka, Shin-ya Miyagishima
Summary: The study reveals that there is a correlation between the number of successive cell divisions and the threshold cell size for cell division in different algae lineages, indicating that the threshold size for cell division plays a major role in determining the number of successive cell divisions. This suggests that evolutionary changes in the mechanism of cell size monitoring result in variations of multiple fission cell cycle in eukaryotic algae.
Article
Ecology
Kohei Takahashi, Hiroko Kawai-Toyooka, Ryo Ootsuki, Takashi Hamaji, Yuki Tsuchikane, Hiroyuki Sekimoto, Tetsuya Higashiyama, Hisayoshi Nozaki
Summary: The study revealed a new haploid mating system in Pleodorina starrii with three sex phenotypes: male, female, and bisexual. Genetic analyses suggested the presence of a autosomal bisexual factor locus independent of volvocine male and female determining regions, providing insight into the initial evolutionary step from heterothallism to homothallism. The findings indicated that the strains belong to the same biological species, with intercrossings demonstrating normal zygote formation and high survivability of F1 strains.
Article
Plant Sciences
Takayuki Fujiwara, Shunsuke Hirooka, Shin-ya Miyagishima
Summary: The unicellular red alga Cyanidioschyzon merolae has a simple cellular and genomic architecture. A new nuclear targeting and transformant selection system using the antibiotic blasticidin S (BS) and the BS deaminase (BSD) selectable marker has been developed in C. merolae. This system enables simultaneous modification of two different chromosomal loci in the same strain, expanding the genetic modification capabilities of this alga.
Article
Multidisciplinary Sciences
Shota Yamashita, Kayoko Yamamoto, Ryo Matsuzaki, Shigekatsu Suzuki, Haruyo Yamaguchi, Shunsuke Hirooka, Yohei Minakuchi, Shin-ya Miyagishima, Masanobu Kawachi, Atsushi Toyoda, Hisayoshi Nozaki
Summary: Germ-soma differentiation evolved independently in eukaryotes, with Volvox and Astrephomene showing convergent evolution in this process. However, the molecular genetic bases and regulatory mechanisms of their germ-soma differentiation differ between the two species.
SCIENTIFIC REPORTS
(2021)
Article
Plant Sciences
Hisayoshi Nozaki, Wuttipong Mahakham, Wirawan Heman, Ryo Matsuzaki, Masanobu Kawachi
Summary: The study reveals the high diversity in mating systems of Volvox africanus, with the third mating system potentially representing an evolutionary transition from heterothallism to homothallism. Further research in stable intracontinental regions could contribute to the understanding of diversity and taxonomy of the freshwater green algal genus Volvox.
Article
Plant Sciences
Tomoyuki Takano, Hisato Ikegaya, Kenichi Ikeda, Hisayoshi Nozaki, Hidetoshi Sakayama
Summary: Characteristics of transverse walls and modes of conjugation are crucial for species identification in the genus Spirogyra. This study examined two Spirogyra species with different types of transverse walls collected in Japan and found their distinct vegetative and reproductive traits. Molecular phylogenetic analyses also revealed their separate lineages in the tree of Spirogyra species. The two Japanese strains are described as new species, S. minuticrassispina sp. nov. and S. tertia sp. nov.
Article
Multidisciplinary Sciences
Shunsuke Hirooka, Takeshi Itabashi, Takako M. Ichinose, Ryo Onuma, Takayuki Fujiwara, Shota Yamashita, Lin Wei Jong, Reiko Tomita, Atsuko H. Iwane, Shin-Ya Miyagishima
Summary: This study discovered that Galdieria exhibits a sexual life cycle, alternating between cell-walled diploid and cell wall-less haploid, while also having the ability for asexual reproduction. By studying the genome and transcriptome data of Galdieria, key transcription factors involved in cell transition and development were identified. Additionally, four actin genes were found to have different functions in motility and cytokinesis between the haploid and diploid stages, reflecting ancestral roles of actin. Furthermore, photosynthesis-deficient mutants were generated for potential industrial pigment production. Overall, these findings enhance our understanding of algae and plant evolution, as well as the industrial use of microalgae.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Biology
Shoichi Kato, Osami Misumi, Shinichiro Maruyama, Hisayoshi Nozaki, Yayoi Tsujimoto-Inui, Mari Takusagawa, Shigekatsu Suzuki, Keiko Kuwata, Saki Noda, Nanami Ito, Yoji Okabe, Takuya Sakamoto, Fumi Yagisawa, Tomoko M. M. Matsunaga, Yoshikatsu Matsubayashi, Haruyo Yamaguchi, Masanobu Kawachi, Haruko Kuroiwa, Tsuneyoshi Kuroiwa, Sachihiro Matsunaga
Summary: Multi-omic and evolutionary analyses of the ultrasmall green alga, Medakomo hakoo, suggest it belongs to a new genus within the class Trebouxiophyceae and provide insight into essential genes for microalgae. With a genome size of 15.8 Mbp and 7629 genes, it is among the smallest genomes in the Viridiplantae. Comparative analyses reveal shared gene sets among 15 ultrasmall algae, enabling identification of essential genes for metabolism and cellular functions.
COMMUNICATIONS BIOLOGY
(2023)
Article
Multidisciplinary Sciences
Kayoko Yamamoto, Ryo Matsuzaki, Wuttipong Mahakham, Wirawan Heman, Hiroyuki Sekimoto, Masanobu Kawachi, Yohei Minakuchi, Atsushi Toyoda, Hisayoshi Nozaki
Summary: By comparing genome data from Thai and Japanese genotypes of the homothallic green alga Volvox africanus, it was found that expanded ancestral male and female sex-determining regions (SDRs) may have originated from an ancient heterothallic ancestor and were conserved during the evolution of homothallic genotypes. An expanded SDR-like region appears to be essential for homothallic sexual reproduction in V. africanus, regardless of its male or female origin. This study highlights the future possibility of elucidating the biological significance of these expanded genomic regions.
Article
Biology
Kohei Takahashi, Shigekatsu Suzuki, Hiroko Kawai-Toyooka, Kayoko Yamamoto, Takashi Hamaji, Ryo Ootsuki, Haruyo Yamaguchi, Masanobu Kawachi, Tetsuya Higashiyama, Hisayoshi Nozaki
Summary: The coexistence of three sexual phenotypes (male, female and bisexual) in a single species, 'trioecy', has been observed in a green algal species, P. starrii, due to the reorganization of ancestral sex chromosomes.
COMMUNICATIONS BIOLOGY
(2023)
Article
Ecology
Ryo Matsuzaki, Shigekatsu Suzuki, Haruyo Yamaguchi, Masanobu Kawachi, Yu Kanesaki, Hirofumi Yoshikawa, Toshiyuki Mori, Hisayoshi Nozaki
Summary: The study suggests that the hydrophobicity of RBCS helices is roughly correlated with the presence or absence of pyrenoids within the Reticulata group, and a decrease in hydrophobicity of RBCS helices may have primarily caused pyrenoid loss during the evolution of this group. This provides novel insight into a potential mechanism determining initial evolutionary steps of gain and loss of the pyrenoid.
BMC ECOLOGY AND EVOLUTION
(2021)