NotesNOSTOC COMMUNE

Value AttributeBacteria Domain

Eubacteria KingdomCyanobacteria Phylum

Taxonomic ClassNostocales Order

Nostocaceae FamilyNostoc Family

N. commune Species

Scientific classification

Nostoc commune

Nostoc commune

Nostoc commune is a colonial species of cyanobacterium.

It initially forms a small, hollow gelatinous globule which grows and becomes leathery, flattened and convoluted, forming a gelatinous mass with other colonies growing nearby.

Inside the thin sheath are numerous unbranched hair-like structures called trichomes formed of short cells in a string.

Description

Cells have no nucleus nor internal membrane system.

To multiply, they form two new cells when they divide by binary fission.

Along the trichomes, larger specialist nitrogen-fixing cells called heterocysts occur between the ordinary cells.

When wet, Nostoccommune is bluish-green, olive green or brown but in dry conditions it becomes an inconspicuous.

Description

It is able to survive in extreme conditions in polar regions and arid areas.

It is a terrestrial or freshwater species and forms loose clumps on soil, gravel and paved surfaces, among mosses and between cobbles.

In Singapore, Nostoc commune is found growing on alkaline soils, in brackish water, in paddy fields, on cliffs and on wet rocks.

Distribution and habitat

Nostoc commune can fix nitrogen from the atmosphere and can live in locations where no nitrogenous compounds are available from the substrate.

Nostoc commune does not have chloroplasts but contains photosynthetic pigments in the cytoplasm of the cells.

It also contains pigments that absorb long and medium wavelength ultraviolet radiation, which enables it to survive in places with high levels of radiation.

Biology

Under adverse conditions, Nostoc commune can remain dormant for an extended period of time and revive when conditions improve and water becomes available.

The desiccated colony is resistant to heat and to repeated patterns of freezing and thawing and produces no oxygen while dormant.

It has been found that extracellular polysaccharides are vital to its stress tolerance and ability to recover.

Biology

Nostoc commune is eaten as a salad in the Philippines and is also eaten in Indonesia, Japan and Taiwan.

Uses