Characterization of cyanobacteria isolated from biofilms on stone monuments at Santiniketan, India

Abstract

Cyanobacterial biofilms occurring on the exterior of three stone monuments at Santiniketan, India were analyzed. Species of Scytonema and Tolypothrix were the major components of these biofilms. Identification was obtained by morphometric procedures and 16S rRNA gene sequencing. Biofilms cultured for prolonged periods revealed the presence of several other cyanobacteria belonging to 14 different genera. Cyanobacteria on stone in the tropical environment of India formed a distinct cluster that was quite different from that of cyanobacteria reported for a similar substratum in temperate regions. Absorption spectra of the organisms from Santiniketan showed a high quantity of scytonemin, mycosporine-like amino acids, and carotenoids. All of the organisms survived in a desiccated state and rapidly revived after wetting. The organisms were heterocystous and nitrogenase activity was reactivated within 24 h of wetting by which time heterocysts in their filaments had also appeared.

Diversity of Cyanobacteria in Biological Crusts on Arid Soils in the Eastern Region of India and their Molecular Phylogeny

“…The protocols for 16S rRNA gene amplification using PCR and molecular phylogeny analysis were as described earlier 16 . Upon amplification, the fragment length of cyanobacteria from desiccated habitats was always small (not exceeding 500 bp) 16,18,19 , which was also reported by other workers [20][21][22] . The PCR products were purified using Qiagen gel extraction kit and sequenced with the help of GCC Biotech, Kolkata, India.…”

Characterization of a Cyanobacterial Chloride-pumping Rhodopsin and Its Conversion into a Proton Pump

“…1B) (23,29,30). Correspondingly, the desiccation resistance was experimentally confirmed for several strains (31). Two strains also contain the gene for Anabaena sensory rhodopsin, a putative sensor for chromatic adaptation that was originally discovered in the cyanobacterium Anabaena sp.…”

Anhydrobiosis and programmed cell death in plants: Commonalities and Differences

“…A specimen of Nostoc commune -a terrestrial cyanobacterium, which was stored in desiccated state for more than 100 years, retained its ability to grow on rehydration [25,26]. In tropical and sub-tropical countries, blackish brown patches of cyanobacteria are very common on the surfaces of old buildings and bark of trees [19,27,28]. These cyanobacteria have been reported to survive extreme desiccation along with surface temperature which sometimes reaches up to 68 • C during summer season.…”