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Cytology of long-term desiccation in the desert cyanobacterium Chroococcidiopsis (Chroococcales)Young and old cultures (up to 66 months) of two Chroococcidiopsis sp. strains isolated from the Negev desert, Israel, were examined by epifluorescence and electron microscopy. In old cultures, cell viability and autofluorescence were lower than in young cultures. An increase was seen with age in the polysaccharide content of the sheaths of nanocytes and nanocyte mother cells, and a decrease of phycobiliproteins was also seen. In the oldest cultures most of the cells were dead and in various stages of degeneration. Single living cells were scattered among the dead ones. No resting cells were formed in the oldest cultures, but many cell groups showed highly electron-dense sheaths and, in the cytoplasm, ribosomes and glycogen. These changes in cell structure may have a role in preventing water loss from the cell.
Document ID
20040089714
Document Type
Reprint (Version printed in journal)
Authors
Caiola, M. G. (University of Rome Italy)
Ocampo-Friedmann, R.
Friedmann, E. I.
Date Acquired
August 21, 2013
Publication Date
January 1, 1993
Publication Information
Publication: Phycologia
Volume: 32
Issue: 5
ISSN: 0031-8884
Subject Category
Exobiology
Funding Number(s)
CONTRACT_GRANT: NAGW1-871
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Exobiology
Non-NASA Center