Article
Biology
Maria Elisa Pavan, Federico Movilla, Esteban E. Pavan, Florencia Di Salvo, Nancy I. Lopez, M. Julia Pettinari
Summary: This study reports the discovery of extracellular crystals formed by bacteria, which are composed of guanine monohydrate. These bacterial guanine crystals differ in composition from the biogenic guanine crystals found in other organisms, which are mostly composed of beta anhydrous guanine. The presence of bacterial guanine crystals correlates with the absence of guanine deaminase, which could lead to guanine accumulation and crystal formation.
Article
Chemistry, Multidisciplinary
Avital Wagner, Vladimir Ezersky, Raquel Maria, Alexander Upcher, Tali Lemcoff, Eliahu D. Aflalo, Yael Lubin, Benjamin A. Palmer
Summary: By studying guanine crystal formation in spiders, it is revealed that guanine crystallization is a non-classical, multistep process involving nucleation of ordered nanogranules, growth through attachment of nanogranules into platelets, and relaxation of structural defects to form single crystals. The findings provide insights on how organisms control the morphology and optical properties of molecular crystals.
ADVANCED MATERIALS
(2022)
Article
Biochemistry & Molecular Biology
Priyanka Pradeep Patil, Imre Vass, Milan Szabo
Summary: Photosynthesis is a series of redox reactions that involve electron transport processes. The cyclic electron flow plays a role in fine tuning photosynthesis. In this study, we characterized the electron transport processes in microalgae and found a wave phenomenon in the fluorescence relaxation profiles, which is a species-specific indicator of the redox reactions and cyclic electron flow.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Analytical
Gerardo Grasso, Giulia Cocco, Daniela Zane, Chiara Frazzoli, Roberto Dragone
Summary: Using microalgae-based fluorimetric bioassays, the study investigated the impact of the phenylurea herbicide Diuron on the photosynthesis of a freshwater and soil model microalga. The results showed that Diuron had inhibitory effects on the photosynthetic process of the microalga.
Article
Biotechnology & Applied Microbiology
Jiri Masojidek, Karolina Ranglova, Martina Beckova, Giuseppe Torzillo, Jana Knoppova, Ana Margarita Silva Benavides, Filip Charvat, Josef Komenda
Summary: The photosynthetic performance and electron transport rate of Chlorella cultures with reduced antenna size were studied during outdoor trials. The results showed that the strain with reduced antenna size had lower oxygen production and electron transport rate, but higher non-photochemical quenching and respiration compared to the strain with full antenna size. These findings suggest that the use of microalgae strains with reduced antenna size for outdoor mass cultivation may not be as effective as expected.
JOURNAL OF APPLIED PHYCOLOGY
(2022)
Article
Environmental Sciences
Na Li, Zhen Liu, Pengcheng Wang, Kapur Suman, Junyan Zhang, Yongxin Song
Summary: Chlorophyll fluorescence-based method is a promising tool for assessing the vitality of algae in treated ship's ballast water. This study investigated the effects of NaClO treatments on the chlorophyll fluorescence kinetics and spectra of two microalgae species. The results revealed that NaClO significantly inhibited the PSII reaction centers of algae and caused changes in the antenna light-absorbing pigments.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Stephanie Aparicio, Angel Robles, Jose Ferrer, Aurora Seco, Luis Borras Falomir
Summary: Total nitrite accumulation due to the activity of ammonia-oxidizing bacteria was monitored in microalgae-bacteria consortia, with a focus on the inhibitory effect of nitrite/free nitrous acid on microalgae photosynthesis and the mechanism of inhibition. The results showed that nitrite accumulation had a negative impact on net oxygen production rate and hindered the electron transport chain between Photosystems II and I at certain concentrations. The inhibitory effects were correctly modeled by Hill-type models, with specific half inhibition constants for different parameters.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Biotechnology & Applied Microbiology
Jiri Masojidek, Karolina Ranglova, Tomas Agustin Rearte, Paula S. M. Celis Pla, Giuseppe Torzillo, Ana Margarita Silva Benavides, Amir Neori, Cintia Gomez, Felix Alvarez-Gomez, Martin Lukes, Martin P. Caporgno, Roberto Abdala, Krystian Miazek, Thais Favero Massocato, Jaqueline Carmo da Silva, Richard Atzmueller, Hafidh Al Mahrouqui, Francisca Suarez Estrella, Felix L. Figueroa
Summary: This study investigated the trophic conversion of microalgae Chlorella vulgaris g120 from heterotrophic to phototrophic growth regime. It was found that Chlorella g120 can undergo this metabolic shift, with high respiration rate as a strategy to dissipate unused light energy. The small-antenna size strain and high carotenoid/chlorophyll ratio of Chlorella g120 may be beneficial for light utilization and carotenoid production.
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2021)
Article
Agricultural Engineering
Yimei Xi, Ying Liu, Zhanyou Chi, Liang Yin, Lijuan Wang, Guanghong Luo
Summary: Carbon-ion irradiation induced mutant DS240G-1 in microalgae exhibited significantly increased biomass, growth rate, beta-carotene content, and total fatty acid content compared to the wild type. Analysis of chlorophyll fluorescence parameters suggested that the improved quantum efficiency and reduced thermal dissipation of photosynthesis in DS240G-1 contributed to the higher beta-carotene productivity. Additionally, the study revealed that high ROS content may also induce beta-carotene accumulation in the mutant DS240G-1.
INTERNATIONAL JOURNAL OF AGRICULTURAL AND BIOLOGICAL ENGINEERING
(2021)
Article
Environmental Sciences
Hugo Virgilio Perales-Vela, Martha Ofelia Salcedo-Alvarez, Rogelio Parra-Marcelo, Llarai Carolina Gaviria-Gonzalez, Alfredo De Jesus Martinez-Roldan
Summary: The study found that increasing concentrations of methyl viologen can lead to decreased growth, pigment content, and metabolic activity of Chlorella vulgaris. Inhibition of electron transport between quinone A and quinone B of photosystem II by MV directly impacts photosynthetic electron transport.
Article
Environmental Sciences
Tingting Gan, Gaofang Yin, Nanjing Zhao, Xiaoxuan Tan, Ying Wang
Summary: Heavy metals as toxic pollutants have significant impacts on microalgae photosynthesis, posing a serious threat to the aquatic ecosystem. This study investigated the effects of four typical toxic heavy metals on various photosynthetic fluorescence parameters of microalga Chlorella pyrenoidosa and identified the most suitable response index for sensitive detection of heavy metal toxicity.
Article
Green & Sustainable Science & Technology
Giovanna Salbitani, Francesco Del Prete, Simona Carfagna, Giovanni Sansone, Carmela M. A. Barone
Summary: The study demonstrates that the addition of bicarbonate to Nannochloropsis oculata cultures can significantly enhance algal growth and pigment contents, especially at higher concentrations. Bicarbonate from 30 to 60 mM can rapidly improve the cellular levels of chlorophylls and carotenoids in a short period of time, providing a sustainable opportunity to improve microalgae cultivation.
Article
Plant Sciences
Collin J. Steen, Adrien Burlacot, Audrey H. Short, Krishna K. Niyogi, Graham R. Fleming
Summary: This study monitored non-photochemical quenching (NPQ) in intact cells throughout high light/dark cycles of various illumination periods and found that the dynamics of NPQ depend on the timescales of light fluctuations. LHCSR proteins play a major role during the light phases, while state transition activation contributes to NPQ response during dark phases.
PLANT CELL AND ENVIRONMENT
(2022)
Article
Biochemistry & Molecular Biology
Giuseppe Torzillo, Felix Alvarez-Gomez, Paula S. M. Celis-Pla, Agustin Rearte, Cintia Gomez-Serrano, Ana Margarita Silva Benavides, Karolina Sterbova, Martin Caporgno, Eleftherios Touloupakis, Jiri Masojidek, Felix L. Figueroa
Summary: This study investigated photosynthesis, growth, and biochemical composition of the biomass of the freshwater microalga Chlamydopodium fusiforme in outdoor thin-layer cascade cultures. The results showed that fluorescence-based photosynthesis rates may not fully replace oxygen measurements for evaluating outdoor cultures. The daily gross biomass productivity remained consistent at 0.3 g DW L-1 day(-1) for 4 days. The findings are important for the potential utilization of Chlamydopodium fusiforme as a novel species for bio-based compound production.
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
(2023)
Article
Chemistry, Analytical
Yanjuan Wang, Junsheng Wang, Tianqi Wang, Chengxiao Wang
Summary: A novel method combining fluorescence and bright field images was proposed to simultaneously detect the viability and concentration of microalgae cells in ship ballast water. Experimental results showed that the self-developed prototype system could quickly and accurately determine the concentration and viability of microalgae cells, with detection accuracy equivalent to that of commercial microscope. This study is the first to develop a miniaturized microscopic imaging prototype for detecting microalgae in ship ballast water, which is expected to contribute to microalgae detection and ship ballast water management.
Article
Nanoscience & Nanotechnology
A. Mootha, Y. Takanezawa, M. Iwasaka
Article
Nanoscience & Nanotechnology
M. Iwasaka
Article
Nanoscience & Nanotechnology
K. Baba, M. Iwasaka
Article
Nanoscience & Nanotechnology
Y. Fukagawa, M. Iwasaka
Article
Nanoscience & Nanotechnology
Archana Mootha, Kentaro Suzuki, Takayuki Kimura, Masaru Kurahashi, Etsuhiro Muneyama, Masakazu Iwasaka, Hironori Asada
Article
Engineering, Electrical & Electronic
Tomohito Sogame, Masaru Kurahashi, Etsuhiro Muneyama, Masakazu Iwasaka, Kengo Kishimoto, Tsuyoshi Koyanagi, Hironori Asada
IEEE TRANSACTIONS ON MAGNETICS
(2019)
Article
Nanoscience & Nanotechnology
Hironori Asada, Etsuhiro Muneyama, Ryosuke Nagai, Takayuki Kimura, Masakazu Iwasaka
Article
Nanoscience & Nanotechnology
Ryosuke Nagai, Masaru Kurahashi, Kengo Kishimoto, Tsuyoshi Koyanagi, Masakazu Iwasaka, Hironori Asada
Article
Nanoscience & Nanotechnology
Masakazu Iwasaka
Article
Engineering, Electrical & Electronic
Yuka Takeuchi, Masakazu Iwasaka, Mizushi Matsusda, Atom Hamasaki
Summary: Monosodium urate (MSU) crystals exhibit different light scattering intensities in forward, sideward, and backward directions under a magnetic field, aiding in gout diagnosis. It is necessary to collect light scattering information from all angles, as applying a magnetic field helps decrease the scattered light intensity of MSU crystals.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Multidisciplinary Sciences
Masakazu Iwasaka
Summary: The study shows that Atherinomorus lacunosus is able to use ambient light effectively for biological signalling through rhythmic flashing of circular spots on its dorsal trunk, providing evidence for the existence of rapid colour changing teleost fish.
ROYAL SOCIETY OPEN SCIENCE
(2021)
Article
Physics, Applied
Masakazu Iwasaka
Summary: The study found that circular cells in the iris of hardyhead silverside fish changed their light intensity at approximately 2 Hz, leading to a color change. These cells, 5-10 μm in diameter and normally blue, showed a distinct light intensity change in 0.04 s, resulting in an overlap with green and yellow colors.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
Masakazu Iwasaka
Summary: This study visualized guanine micro-platelets floating in water through light projection and revealed their light scattering behavior in specific directions. By setting a thin water layer on top of the image sensor's cover glass, the platelets formed column- or bar-code-shaped images on the screen. The existence of nanohole gratings in the platelets was confirmed, and numerical simulations showed that these gratings contributed to the formation of unique light projection spots.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Yuka Takeuchi, Yuta Wada, Atom Hamasaki, Masakazu Iwasaka, Mizushi Matsuda
IEEE TRANSACTIONS ON MAGNETICS
(2019)
Article
Engineering, Electrical & Electronic
Masakazu Iwasaka, Masaaki Hayashi, Kyohei Hamamura, Hironori Asada, Yuichi Oba
IEEE TRANSACTIONS ON MAGNETICS
(2019)
