To the technique of studying the structure of bacteria

1926 ◽  
Vol 22 (10) ◽  
pp. 1178-1178
Author(s):  
F. Ya. Kitaev

The author found that such microbes as diphtheria, typhoid and anthrax bacilli have clearly differentiated nuclei. The latter, however, are mostly invisible due to the presence in the bacterial cell of a protein substance (deutoplasm), which has the ability to perceive coloring particularly well; surrounding the nucleus on all sides, this substance makes it invisible.

2020 ◽  
Vol 85 ◽  
pp. 131-139
Author(s):  
S Shen ◽  
Y Shimizu

Despite the importance of bacterial cell volume in microbial ecology in aquatic environments, literature regarding the effects of seasonal and spatial variations on bacterial cell volume remains scarce. We used transmission electron microscopy to examine seasonal and spatial variations in bacterial cell size for 18 mo in 2 layers (epilimnion 0.5 m and hypolimnion 60 m) of Lake Biwa, Japan, a large and deep freshwater lake. During the stratified period, we found that the bacterial cell volume in the hypolimnion ranged from 0.017 to 0.12 µm3 (median), whereas that in the epilimnion was less variable (0.016 to 0.033 µm3, median) and much lower than that in the hypolimnion. Additionally, in the hypolimnion, cell volume during the stratified period was greater than that during the mixing period (up to 5.7-fold). These differences in cell volume resulted in comparable bacterial biomass in the hypolimnion and epilimnion, despite the fact that there was lower bacterial abundance in the hypolimnion than in the epilimnion. We also found that the biomass of larger bacteria, which are not likely to be grazed by heterotrophic nanoflagellates, increased in the hypolimnion during the stratified period. Our data suggest that estimation of carbon flux (e.g. bacterial productivity) needs to be interpreted cautiously when cell volume is used as a constant parametric value. In deep freshwater lakes, a difference in cell volume with seasonal and spatial variation may largely affect estimations.


2002 ◽  
Vol 22 (1-2) ◽  
pp. 209-222 ◽  
Author(s):  
Bénédicte Flambard

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