The lichen with a green photobiont
(Chlorophyta 84%) predominates while the cyanobacteria photobiont
(15%) is less represented.
One hundred and seventy-eight (88%) species have green algae as a primary photobiont
, eight (4%) species have cyanobacteria as their primary photobiont
, and 17 species (8%) are nonlichenized fungi traditionally treated with lichens.
Lichens are in fact an ecosystem comprising of a photobiont
that can either be a green alga (Chlorophyta) or a cyanobacterium and a mycobiont that in most cases belongs to the Ascomycetes.
After 120 h of exposure to simulated but representative Martian atmospheric, temperature, pressure and UV conditions, the photosynthetic performance of the lichen photobiont
was unaltered, demonstrating its high resistance to these harsh conditions (Sanchez Inigo et al.
It is also known as a photobiont
in lichens (BUDEL & HENSSEN, 1988).
Lichens: Composite organisms consisting of a fungus (the mycobiont) and a photosynthetic partner (the photobiont
or phycobiont), usually an alga or cyanobacteria, growing together in a symbiotic relationship.
Ahmadjian (1993b) also pointed to a lack of evidence for adaptation in the photobiont
a blue-green alga; thallus growing on thin soils over dolomite bedrock; apothecia immersed in upper surface HEPPIA 2.
Indeed, in many cases, the mycobiont extends tiny tubes called haustoria deep into the photobiont
cells, to obtain a continual sugar supply.
missouriense filaments revealed 1) common to abundant occurrence of cyanobacteria colonies attached to the exposed walls of the fungus component, and 2) cobblestone-shaped fungus cells that grew into short filaments beyond the apical cell of the photobiont
13]C of lichens can vary with the photobiont
associated with the symbiosis, but values are generally lower than -23[per thousand] (Lange 1988, Maguas et al.
Lichens are complex symbiotic associations between a fungus (mycobiont) and photobiont
which can be either an alga or cyanobacteria (Bates et al.