[Morphologic changes in the life cycle of Cytophaga hutchinsonii].
OBJECTIVE
To study the morphological changes of Cytophaga hutchinsonii cell during its life circle.


METHODS
Cytophaga hutchinsonii cell was observed under light microscope, fluorescence microscope and scanning electron microscope. The nucleoids in the cell were stained with fluorescent dye Hoechst33342 and examined by fluorescence microscopy.


RESULTS
We discovered that under starvation conditions, the long, flexible rod cell of Cytophaga hutchinsonii would bend and turn into circular cell. The circular cell failed to produce carboxymethyl cellulase. Some of the circular cells might further wind around and turn into tiny spherical cells. The tiny spherical cell similar to the microcyst of sporocytophaga could germ into long flexible rods again under certain circumstances. When growing cultures to logarithmic phase of cell growth, Cytophaga hutchinsonii cell with three nucleoids in it was occasionally observed, which indicated that the two strands of DNA might act differently in the initiation of DNA replication.


CONCLUSIONS
This is the first detailed description of the formation process of circular cell and tiny spherical cell in the life circle of Cytophaga hutchinsonii. The result will help to further reveal the relation between morphologic change and cellulose degradation ability of the strain.
Han
Wenbin
W
State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China. alan_han@126.com
Xu
Zhengxue
Z
Su
Jing
J
Lu
Xuemei
X
Gao
Peiji
P
D000596:Amino Acids / Q000032:analysis; D000606:Amino Sugars / Q000032:analysis*; D002473:Cell Wall / Q000737:chemistry; D002854:Chromatography, Paper; D003589:Cytophaga / Q000737:chemistry / Q000166:cytology* / Q000648:ultrastructure*; D008854:Microscopy, Electron; D011523:Protoplasts / Q000166:cytology
D000596:Amino Acids; D000606:Amino Sugars