Isolation and cultivation of coccoid Cyanobacteria from aerophytic biofilm in Stopić cave

Abstract

Cyanobacteria, characterized by unique physiological and biochemical mechanisms to withstand harsh conditions in different habitats, can thrive in a variety of environments, including extreme ones such as illuminated parts of caves. The information on diversity, biology and ecology of aerophytic Cyanobacteria, especially those from cave habitats, is very limited, which is especially true for the coccoid forms. Phototrophic biofilm was collected from the entrance zone of Stopić Cave to isolate coccoid Cyanobacteria. The biofilm was inoculated in situ into test tubes containing solid BG11 growth medium, after which the test tubes were kept in a growth chamber under controlled conditions. From the initial culture, which contained multiple cyanobacterial species, subsamples were extracted and transferred to Petri dishes. These were kept under optimal conditions until a pure cultures were obtained. The representative of the coccoid Cyanobacteria, Chroococcus, was isolated and its characteristics best matched the original description of Chroococcus turgidus.