ISSN:
1432-0991
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract The occurrence and ultrastructure of eubacteria within leaf cavities of symbiotic and cyanobiont-freeAzolla mexicana were examined with transmission electron microscopy. Bacteria were observed in all leaf cavities of bothAzolla cultures, showing increasing numbers concomitant with leaf age. In symbioticAzolla mexicana two ultrastructurally distinct types of bacteria were found; a helical bacterium and a slightly curved, rod-shaped bacterium. Both had typical Gram-negative cell wall ultrastructure. The helical bacteria comprised 60% of the total population in young leaf cavities (1–5) and 74–80% of the population in older cavities. The mode of cell division for the rod-shaped bacterium was binary fission. In cyanobiont-freeAzolla mexicana at least three distinct types of bacteria were observed; two were ultrastructurally similar to, if not identical, with the types present in symbioticAzolla mexicana.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02091830
