Can cyanobacteria form akinetes?

Some cyanobacteria of the order Nostocales can form akinetes, spore-like dormant cells resistant to various unfavorable environmental fluctuations.

What are akinetes and what is their function?

Akinetes are spore-like non-motile cells that differentiate from vegetative cells of filamentous cyanobacteria from the order Nostocales. They play a key role in the survival and distribution of these species and contribute to their perennial blooms.

What is the difference between heterocyst and akinetes?

Akinetes (Greek “akinetos”) are motionless, spore-like resting cells that differentiate from vegetative cells and serve in perennation. Akinetes are larger (sometimes up to 10-fold) than vegetative cells, and heterocysts possess thickened cell wall and a multilayered extracellular envelope (Adams and Duggan, 1999).

Where are akinetes found?

Abstract. Akinetes are dormancy cells commonly found among filamentous cyanobacteria, many of which are toxic and/or nuisance, bloom-forming species. Development of akinetes from vegetative cells is a process that involves morphological and biochemical modifications.

What is the function of akinetes in cyanobacteria?

Akinetes are dormant cells of cyanobacteria species from the Nostocales and Stigonematales orders, allowing these phototrophic bacteria to survive in harsh and starvation conditions. These spore-like thick-walled, nonmotile cells differentiate from vegetative cells in response to environmental fluctuations.

Which mode of reproduction is the formation of akinetes?

Asexual reproduction is by the formation of resting spores known as akinetes. Some of the cells become thick-walled due to accumulation of food. They can withstand unfavourable conditions for many years. Under favourable conditions, they germinate to form a new filament.

In which akinetes are algae found?

cyanobacteria
An akinete is a thick-walled dormant cell derived from the enlargement of a vegetative cell. 1 It serves as a survival structure. It is a resting cell of cyanobacteria and unicellular and filamentous green algae.

What is the difference between Hypnospores and akinetes?

HYPNOSPORE : Hypnospore is a non- motile asexual spore formed within a cell, the wall of which is distinct from that of the parent cell. AKINETES : Akinete is a non motile asexual spore formed within a cell,the wall of which is fused to that of the parent cell.

Why akinetes cells of Nostoc are different from vegetative cells?

Light and electron microscopy revealed that akinetes of both species differed from vegetative cells by their larger size, different cell morphology and large number of intracellular granules.

Which mode of reproduction is the formation of Akinetes?

What is Hypnospores?

Definition of hypnospore : a very thick-walled asexual resting spore (as of various green algae)

Does Nostoc have akinetes?

The akinetes formed in Nostoc strains are often accompanied by dead vegetative cells and hetero- cysts. The cause of this phenomenon is not clear, but it could be related to mechanisms regulating the heterocysts and spore differentiation.

What is the difference between Hypnospores and Akinetes?

What is Zoospores and Aplanospores?

Zoospores and aplanospores are asexual spores produced endogenously in fungi, algae, and protozoans. Zoospores are motile and aplanospores are nonmotile. Zoospores lack a proper cell wall to endure harsh environmental conditions. Hence, they are not considered as resistant units of organisms.

What is the difference between Nostoc and Anabaena?

The main difference between Nostoc and Anabaena is that Nostoc is a genus of cyanobacteria, and forms colonies composed of filaments of moniliform cells in a gelatinous sheath, whereas Anabaena is a genus of filamentous cyanobacteria, and exists as plankton.

Does Gloeocapsa have Akinete?

Akinetes: Absent; some cell resting stages are misinterpreted as akinetes. Aerotopes: Absent.

What is the example of Aplanospores?

An immobile, thin-walled spore that relies on passive transport by water currents. Examples of organisms producing such spores are certain algae and fungi. Word origin: a- (not) + planao- (wandering) + spore.

What is Aplanospores?

Definition of aplanospore 1 : a nonmotile asexual spore formed by rejuvenescence in certain algae and distinguished from an akinete by developing a new cell wall distinct from that of the parent cell — compare hypnospore, zoospore.

Is Nostoc a filamentous BGA?

It was given the name Nostoc by Paracelsus. The blue-green bacteria are cyanobacteria or blue-green algae. Some of them are rod-shaped, some are circular, and some of them are filamentous.

Is Nostoc and Anabaena blue-green algae?

Both Nostoc and Anabaena are cyanobacteria or blue, green algae.

Why do akinete cells need to be kept in dormancy?

This is associated with the accumulation of nucleic acids which is important for both dormancy and germination of the akinete. Despite being a resting cell, it is still capable of some metabolic activities such as photosynthesis, protein synthesis, and carbon fixation, albeit at significantly lower levels.

How do akinetes survive cold and desiccation?

Akinetes are resistant to cold and desiccation. They also accumulate and store various essential material, both of which allows the akinete to serve as a survival structure for up to many years.

Are akinetes resistant to heat?

However, akinetes are not resistant to heat. Akinetes usually develop in strings with each cell differentiating after another and this occurs next to heterocysts if they are present.

What is the function of akinetes?

Akinetes are dormant cells of cyanobacteria species from the Nostocales and Stigonematales orders, allowing these phototrophic bacteria to survive in harsh and starvation conditions. These spore-like thick-walled, nonmotile cells differentiate from vegetative cells in response to environmental fluctuations.