scholarly journals Supra-Optimal Temperature: An Efficient Approach for Overaccumulation of Starch in the Green Alga Parachlorella kessleri

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1806
Author(s):  
Vilém Zachleder ◽  
Veronika Kselíková ◽  
Ivan N. Ivanov ◽  
Vitali Bialevich ◽  
Milada Vítová ◽  
...  
Keyword(s):  
Green Alga ◽  
Time Course ◽  
Neutral Lipids ◽  
Incident Light ◽  
Energy Reserves ◽  
Optimal Temperature ◽  
Algal Biotechnology ◽  
Cell Reproduction ◽  
Parachlorella Kessleri ◽  
Synchronized Cultures

Green algae are fast-growing microorganisms that are considered promising for the production of starch and neutral lipids, and the chlorococcal green alga Parachlorella kessleri is a favorable model, as it can produce both starch and neutral lipids. P. kessleri commonly divides into more than two daughter cells by a specific mechanism—multiple fission. Here, we used synchronized cultures of the alga to study the effects of supra-optimal temperature. Synchronized cultures were grown at optimal (30 °C) and supra-optimal (40 °C) temperatures and incident light intensities of 110 and 500 μmol photons m−2 s−1. The time course of cell reproduction (DNA replication, cellular division), growth (total RNA, protein, cell dry matter, cell size), and synthesis of energy reserves (net starch, neutral lipid) was studied. At 40 °C, cell reproduction was arrested, but growth and accumulation of energy reserves continued; this led to the production of giant cells enriched in protein, starch, and neutral lipids. Furthermore, we examined whether the increased temperature could alleviate the effects of deuterated water on Parachlorella kessleri growth and division; results show that supra-optimal temperature can be used in algal biotechnology for the production of protein, (deuterated) starch, and neutral lipids.

scholarly journals Characterization of Growth and Cell Cycle Events Affected by Light Intensity in the Green Alga Parachlorella kessleri: A New Model for Cell Cycle Research

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 891
Author(s):  
Vilém Zachleder ◽  
Ivan N. Ivanov ◽  
Veronika Kselíková ◽  
Vitali Bialevich ◽  
Milada Vítová ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Light Intensity ◽  
Green Alga ◽  
Neutral Lipids ◽  
Growth Parameters ◽  
Daughter Cells ◽  
Light Intensities ◽  
Multiple Fission ◽  
Parachlorella Kessleri

Multiple fission is a cell cycle variation leading to the production of more than two daughter cells. Here, we used synchronized cultures of the chlorococcal green alga Parachlorella kessleri to study its growth and pattern of cell division under varying light intensities. The time courses of DNA replication, nuclear and cellular division, cell size, total RNA, protein content, dry matter and accumulation of starch were observed at incident light intensities of 110, 250 and 500 µmol photons m−2s−1. Furthermore, we studied the effect of deuterated water on Parachlorella kessleri growth and division, to mimic the effect of stress. We describe a novel multiple fission cell cycle pattern characterized by multiple rounds of DNA replication leading to cell polyploidization. Once completed, multiple nuclear divisions were performed with each of them, immediately followed by protoplast fission, terminated by the formation of daughter cells. The multiple fission cell cycle was represented by several consecutive doublings of growth parameters, each leading to the start of a reproductive sequence. The number of growth doublings increased with increasing light intensity and led to division into more daughter cells. This study establishes the baseline for cell cycle research at the molecular level as well as for potential biotechnological applications, particularly directed synthesis of (deuterated) starch and/or neutral lipids as carbon and energy reserves.

scholarly journals Acclimation temperature affects thermal reaction norms for energy reserves in Drosophila

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Peter Klepsatel ◽  
Thirnahalli Nagaraj Girish ◽  
Martina Gáliková
Keyword(s):  
Thermal Conditions ◽  
Thermal Reaction ◽  
Reaction Norms ◽  
Temperate Climate ◽  
Acclimation Temperature ◽  
Energy Reserves ◽  
Optimal Temperature ◽  
Tropical Zone ◽  
Energy Stores ◽  
Different Temperatures

AbstractOrganisms have evolved various physiological mechanisms to cope with unfavourable environmental conditions. The ability to tolerate non-optimal thermal conditions can be substantially improved by acclimation. In this study, we examined how an early-life acclimation to different temperatures (19 °C, 25 °C and 29 °C) influences thermal reaction norms for energy stores in Drosophila adults. Our results show that acclimation temperature has a significant effect on the amount of stored fat and glycogen (and their relative changes) and the optimal temperature for their accumulation. Individuals acclimated to 19 °C had, on average, more energy reserves than flies that were initially maintained at 25 °C or 29 °C. In addition, acclimation caused a shift in optimal temperature for energy stores towards acclimation temperature. We also detected significant population differences in this response. The effect of acclimation on the optimal temperature for energy stores was more pronounced in flies from the temperate climate zone (Slovakia) than in individuals from the tropical zone (India). Overall, we found that the acclimation effect was stronger after acclimation to low (19 °C) than to high (29 °C) temperature. The observed sensitivity of thermal reaction norms for energy reserves to acclimation temperature can have important consequences for surviving periods of food scarcity, especially at suboptimal temperatures.

Changes in nitric oxide/hydrogen peroxide content and cell cycle progression: Study with synchronized cultures of green alga Chlamydomonas reinhardtii

2017 ◽  
Vol 208 ◽  
pp. 84-93 ◽  
Author(s):  
Wojciech Pokora ◽  
Anna Aksmann ◽  
Agnieszka Baścik-Remisiewicz ◽  
Agnieszka Dettlaff-Pokora ◽  
Max Rykaczewski ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cell Cycle ◽  
Hydrogen Peroxide ◽  
Chlamydomonas Reinhardtii ◽  
Green Alga ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Peroxide Content ◽  
Synchronized Cultures

scholarly journals Time Course of Photosynthetic Response to Changes in Incident Light Energy

1979 ◽  
Vol 63 (6) ◽  
pp. 1033-1038 ◽  
Author(s):  
Louis J. Gross ◽  
Brian F. Chabot
Keyword(s):  
Time Course ◽  
Incident Light ◽  
Light Energy ◽  
Photosynthetic Response

scholarly journals Intrinsic optical and passive electrical properties of cut frog twitch fibers.

1987 ◽  
Vol 89 (1) ◽  
pp. 1-40 ◽  
Author(s):  
M Irving ◽  
J Maylie ◽  
N L Sizto ◽  
W K Chandler
Keyword(s):  
Time Course ◽  
Internal State ◽  
Incident Light ◽  
Operation Mode ◽  
Optical Measurements ◽  
Fiber Axis ◽  
Simple Method ◽  
General Physiology ◽  
Linearly Polarized ◽  
The Individual

This article describes a new apparatus for making simultaneous optical measurements on single muscle fibers at three different wavelengths and two planes of linear polarization. There are two modes of operation: mode 1 measures the individual absorbances of light linearly polarized along and perpendicular to the fiber axis, and mode 2 measures retardation (or birefringence) and the average of the two absorbance components. Although some intact frog twitch fibers were studied, most experiments used cut fibers (Hille, B., and D. T. Campbell. 1976. Journal of General Physiology. 67:265-293) mounted in a double-Vaseline-gap chamber (Kovacs, L., E. Rios, and M. F. Schneider. 1983. Journal of Physiology. 343:161-196). The end-pool segments were usually exposed for 2 min to 0.01% saponin. This procedure, used in subsequent experiments to make the external membranes in the end pools permeable to Ca indicators (Maylie, J., M. Irving, N. L. Sizto, G. Boyarsky, and W. K. Chandler. 1987. Journal of General Physiology. 89:145-176; Maylie, J., M. Irving, N. L. Sizto, and W. K. Chandler. 1987. Journal of General Physiology. 89:41-143), was routinely employed so that all our cut fiber results would be comparable. A simple method, which does not require microelectrodes, allowed continual estimation of a fiber's membrane (rm) and internal longitudinal (ri) resistances as well as the external resistance (re) under the Vaseline seals. The values of rm and ri obtained from cut fibers with this method agree reasonably well with values obtained from intact fibers using microelectrode techniques. Optical measurements were made on resting and action potential-stimulated fibers. The intrinsic fiber absorbance, defined operationally as log10 of the ratio of incident light to transmitted light intensity, was similar in intact and cut preparations, as were the changes that accompanied stimulation. On the other hand, the resting birefringence and the peak of the active change in cut fibers were, respectively, only 0.8 and 0.7 times the corresponding values in intact fibers. Both the amplitude and the half-width of the active retardation signal increased considerably during the time course of cut fiber experiments; a twofold increase in 2 h was not unusual. Such changes are probably due to a progressive alteration in the internal state of the cut fibers.

Toxicity testing with synchronized cultures of the green alga Chlamydomonas

Chemosphere ◽  
1978 ◽  
Vol 7 (3) ◽  
pp. 231-245 ◽  
Author(s):  
Svein Norland ◽  
Mikal Heldal ◽  
Torleiv Lien ◽  
Gjert Knutsen
Keyword(s):  
Green Alga ◽  
Toxicity Testing ◽  
Synchronized Cultures

scholarly journals OXIDATIVE ASSIMILATION IN RELATION TO PHOTOSYNTHESIS IN CHLORELLA

1947 ◽  
Vol 30 (3) ◽  
pp. 217-227 ◽  
Author(s):  
Jack Myers ◽  
Keyword(s):  
Carbon Dioxide ◽  
Acetic Acid ◽  
Green Alga ◽  
Time Course ◽  
Chlorella Pyrenoidosa ◽  
Simultaneous Occurrence ◽  
Storage Material ◽  
Complete Utilization ◽  
Green Alga Chlorella ◽  
Time Required

1. An oxidative assimilation of acetic add and glucose in darkness has been demonstrated in the green alga, Chlorella pyrenoidosa. From manometric experiments it has been shown that 1 mol (CH2O) per mol acetic add and 5 mols (CH2O) per mol glucose are produced. 2. The time required for complete utilization of a limited amount of acetic acid or glucose is not affected by illumination in the absence of carbon dioxide. 3. The time required for complete utilization of a limited amount of glucose is not affected by the simultaneous occurrence of photosynthesis. It must therefore be concluded that the accumulating product of photosynthesis cannot be glucose but must be some slowly respirable (storage) material. 4. Possible interrelationships between oxidative assimilation and photosynthesis may be further studied by following, in darkness and in light, the time course of oxidative assimilation of substrates which are possible intermediates in the two processes.

scholarly journals Deciphering the relationship among phosphate dynamics, electron-dense body and lipid accumulation in the green alga Parachlorella kessleri

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Shuhei Ota ◽  
Mai Yoshihara ◽  
Tomokazu Yamazaki ◽  
Tsuyoshi Takeshita ◽  
Aiko Hirata ◽  
...  
Keyword(s):  
Green Alga ◽  
Lipid Accumulation ◽  
Dense Body ◽  
Parachlorella Kessleri ◽  
The Relationship

scholarly journals Producing Energy-Rich Microalgae Biomass for Liquid Biofuels: Influence of Strain Selection and Culture Conditions

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1246
Author(s):  
Vladimir Heredia ◽  
Olivier Gonçalves ◽  
Luc Marchal ◽  
Jeremy Pruvost
Keyword(s):  
Energy Storage ◽  
Nitrogen Limitation ◽  
Neutral Lipids ◽  
Culture Conditions ◽  
Biodiesel Production ◽  
Biofuel Production ◽  
Freshwater Species ◽  
Nannochloropsis Gaditana ◽  
Parachlorella Kessleri ◽  
Four Levels

Energy-storage metabolites such as neutral lipids and carbohydrates are valuable compounds for liquid biofuel production. The aim of this work is to elucidate the main biological responses of two algae species known for their effective energy-rich compound accumulation in nitrogen limitation and day–night cycles: Nannochloropsis gaditana, a seawater species, and Parachlorella kessleri, a freshwater species. Lipid and carbohydrate production are investigated, as well as cell resistance to mechanical disruption for energy-rich compound release. Nitrogen-depleted N. gaditana showed only a low consumption of energy-storage molecules with a non-significant preference for neutral lipids (TAG) and carbohydrates in day–night cycles. However, it did accumulate significantly fewer carbohydrates than P. kessleri. Following this, the highest levels of productivity for N. gaditana in chemostat cultures at four levels of nitrogen limitation were found to be 3.4 and 2.2 × 10−3 kg/m2·d for carbohydrates and TAG, respectively, at 56%NO3 limitation. The cell disruption rate of N. gaditana decreased along with nitrogen limitation, from 75% (at 200%NO3) to 17% (at 13%NO3). In the context of potentially recoverable energy for biofuels, P. kessleri showed good potential for biodiesel and high potential for bioethanol; by contrast, N. gaditana was found to be more efficient for biodiesel production only.

scholarly journals Syntaxin 17 promotes lipid droplet formation by regulating the distribution of acyl-CoA synthetase 3

2017 ◽  
Author(s):  
Hana Kimura ◽  
Kohei Arasaki ◽  
Yuki Ohsaki ◽  
Toyoshi Fujimoto ◽  
Mitsuo Tagaya
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Raft ◽  
Lipid Droplets ◽  
Time Course ◽  
Neutral Lipids ◽  
Maturation Stage ◽  
Phospholipid Monolayer ◽  
Lipid Droplet Formation ◽  
Initial Stage ◽  
Key Enzyme

AbstractLipid droplets (LDs) are ubiquitous organelles that contain neutral lipids and are surrounded by a phospholipid monolayer. How proteins specifically localize to the phospholipid monolayer of the LD surface has been a matter of extensive investigations. Here we show that syntaxin 17 participates in LD biogenesis by regulating the distribution of acyl-CoA synthetase 3 (ACSL3), a key enzyme for LD biogenesis that redistributes from the endoplasmic reticulum to LDs during LD formation. Time course experiments revealed that syntaxin 17 binds to ACSL3 in the initial stage of LD formation, and that ACSL3 is released as a consequence of competitive binding of SNAP23 to syntaxin 17 in the maturation stage. We propose a model in which ACSL3 redistributes from the endoplasmic reticulum to LDs through association with syntaxin 17 and SNAP23-mediated dissociation from syntaxin 17. We also provide evidence that lipid raft-like structures are important for LD formation and SNAREs-ACSL3 interactions.

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