scholarly journals NADPH‐to‐NADH conversion by mitochondrial transhydrogenase is indispensable for sustaining anaerobic metabolism in Euglena gracilis

FEBS Letters ◽  
2021 ◽  
Author(s):  
Masami Nakazawa ◽  
Mutsuki Takahashi ◽  
Ryuta Hayashi ◽  
Yuki Matsubara ◽  
Yuichiro Kashiyama ◽  
...  
Author(s):  
Hilton H. Mollenhauer ◽  
W. Evans

The pellicular structure of Euglena gracilis consists of a series of relatively rigid strips (Fig. 1) composed of ridges and grooves which are helically oriented along the cell and which fuse together into a common junction at either end of the cell. The strips are predominantly protein and consist in part of a series of fibers about 50 Å in diameter spaced about 85 Å apart and with a secondary periodicity of about 450 Å. Microtubules are also present below each strip (Fig. 1) and are often considered as part of the pellicular complex. In addition, there may be another fibrous component near the base of the pellicle which has not yet been very well defined.The pellicular complex lies underneath the plasma membrane and entirely within the cell (Fig. 1). Each strip of the complex forms an overlapping junction with the adjacent strip along one side of each groove (Fig. 1), in such a way that a certain amount of sideways movement is possible between one strip and the next.


Author(s):  
Tetsuaki Osafune ◽  
Shuji Sumida ◽  
Tomoko Ehara ◽  
Eiji Hase ◽  
Jerome A. Schiff

Changes in the morphology of pyrenoid and the distribution of RuBisCO in the chloroplast of Euglena gracilis were followed by immunoelectron microscopy during the cell cycle in a light (14 h)- dark (10 h) synchronized culture under photoautotrophic conditions. The imrnunoreactive proteins wereconcentrated in the pyrenoid, and less densely distributed in the stroma during the light period (growth phase, Fig. 1-2), but the pyrenoid disappeared during the dark period (division phase), and RuBisCO was dispersed throughout the stroma. Toward the end of the division phase, the pyrenoid began to form in the center of the stroma, and RuBisCO is again concentrated in that pyrenoid region. From a comparison of photosynthetic CO2-fixation with the total carboxylase activity of RuBisCO extracted from Euglena cells in the growth phase, it is suggested that the carboxylase in the pyrenoid functions in CO2-fixation in photosynthesis.


Author(s):  
Tomoko Ehara ◽  
Shuji Sumida ◽  
Tetsuaki Osafune ◽  
Eiji Hase

As shown previously, Euglena cells grown in Hutner’s medium in the dark without agitation accumulate wax as well as paramylum, and contain proplastids showing no internal structure except for a single prothylakoid existing close to the envelope. When the cells are transferred to an inorganic medium containing ammonium salt and the cell suspension is aerated in the dark, the wax was oxidatively metabolized, providing carbon materials and energy 23 for some dark processes of plastid development. Under these conditions, pyrenoid-like structures (called “pro-pyrenoids”) are formed at the sites adjacent to the prolamel larbodies (PLB) localized in the peripheral region of the proplastid. The single prothylakoid becomes paired with a newly formed prothylakoid, and a part of the paired prothylakoids is extended, with foldings, in to the “propyrenoid”. In this study, we observed a concentration of RuBisCO in the “propyrenoid” of Euglena gracilis strain Z using immunoelectron microscopy.


1972 ◽  
Vol 27 (02) ◽  
pp. 263-271 ◽  
Author(s):  
I. A. Cooper ◽  
P Cochrane ◽  
B. G. Firkin ◽  
K. J. Pinkard

SummaryIt has been suggested that human platelets possess the ability to phagocytose particulate matter similar to the polymorphonuclear leukocyte. However some difference of opinion has arisen regarding this contention, particularly as differences have been demonstrated with regard to the observed metabolic changes occurring in platelets related to such a process.The experiments reported in this paper were designed to observe the aerobic and anaerobic metabolism in human platelets during and following interiorization of two different particles, viz. polystyrene latex and thorotrast. The results of these experiments show a marked difference between both types of particles with regard to observable metabolic changes despite the rapid interiorization of both types of material. Some alteration occurs in both aerobic and anaerobic metabolism a considerable time after interiorization of latex, whereas no alteration could be demonstrated after interiorization of thorotrast. It is suggested that the interiorization of particulate matter is by some process other than phagocytosis and that observed metabolic changes related to latex may be due to a release reaction.


2007 ◽  
Vol 9 (3) ◽  
pp. 222-235
Author(s):  
I. P. Novikova ◽  
T. V. Parshikova ◽  
V. V. Vlasenko ◽  
I. B. Zubenko

2015 ◽  
Vol 8 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Ignacio Irazoqui ◽  
Alfonso Rodriguez ◽  
Estefanía Birriel ◽  
Martin Gabay ◽  
Maria Lavaggi ◽  
...  

1982 ◽  
Vol 37 (3-4) ◽  
pp. 256-259 ◽  
Author(s):  
F. Schuler ◽  
P. Brandt ◽  
W. Wießner

Abstract An improved method for isolation of (photosystem II)-particles from Euglena gracilis, strain Z was established. PS II-particles isolated by ultrasonic treatment and following differential centrifugation show fluorescence emission and absorption spectra identical with in vivo properties of Euglena gracilis. These PS II-particles have only PS II-activity and contain CP a, the typical chlorophyll-protein-complex of PS II. No contamination of PS I-components are detectable.


2021 ◽  
Vol 9 (7) ◽  
pp. 1496
Author(s):  
Rubiyatno ◽  
Kazuhiro Mori ◽  
Daisuke Inoue ◽  
Sunah Kim ◽  
Jaecheul Yu ◽  
...  

Euglena gracilis produces paramylon, which is a feedstock for high-value functional foods and nutritional supplements. The enhancement of paramylon productivity is a critical challenge. Microalgae growth-promoting bacteria (MGPB) can improve microalgal productivity; however, the MGPB for E. gracilis remain unclear. This study isolated bacteria capable of enhancing E. gracilis growth and paramylon production under mixotrophic conditions. Enterobacter sp. CA3 and Emticicia sp. CN5 were isolated from E. gracilis grown with sewage-effluent bacteria under mixotrophic conditions at pH 4.5 or 7.5, respectively. In a 7-day E. gracilis mixotrophic culture with glucose, CA3 increased E. gracilis biomass and paramylon production 1.8-fold and 3.5-fold, respectively (at pH 4.5), or 1.9-fold and 3.5-fold, respectively (at pH 7.5). CN5 increased E. gracilis biomass and paramylon production 2.0-fold and 4.1-fold, respectively (at pH 7.5). However, the strains did not show such effects on E. gracilis under autotrophic conditions without glucose. The results suggest that CA3 and CN5 promoted both E. gracilis growth and paramylon production under mixotrophic conditions with glucose at pH 4.5 and 7.5 (CA3) or pH 7.5 (CN5). This study also provides an isolation method for E. gracilis MGPB that enables the construction of an effective E. gracilis–MGPB-association system for increasing the paramylon yield of E. gracilis.


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