جستجوی مقالات مرتبط با کلیدواژه "فیشرلا" در نشریات گروه "زیست شناسی"

The aim of this study was to investigate the adaptation of the cyanobacterium Fischerella sp. ISC 107to combined effects of carbon dioxide concentration, acidic and alkalinity. Axenic strain was incubated in BG0-11 medium. Carbon dioxide treatments were limited and relatively non-limited. Acidic (pH 5), neutral (pH7), and alkaline (pH 9) conditions were employed in each treatment. Survival, growth, chlorophyll, phycocyanin, allophycocyanin, and phycoerythrin contents were evaluated in each treatment along with ammonium liberation, frequency, and biometry of heterocyst. Results showed that like other explored stigonematalean and nostocalean cyanobacteria, this strain cannot grow in acidic condition. Under limited carbon dioxide condition, difference in growth rates were not significant between acidic and alkaline conditions; however, carbon dioxide enrichment caused significant increase in growth rates. Phycobilisome system of this strain lacked phycoerythrin and may complete its structure both at the core and the rod under alkaline condition. Heterocyst frequency and biometry were maximum at alkaline condition showing significant correlation with nitrogenase activity. Heterocyst showed cylindrical and sub-cylindrical morphology on days 4and 5 after inoculation. Overall, the results showed that this strain may be qualified to be used as a biofertilizer similar to the other cyanobacteria.

In a multidisciplinary way, taxonomical characterization of the cyanobacterium Fischerella ambigua (Nägeli) Gomont, collected from paddy-fields of North of Iran have been investigated. Beside morphologies, ecophysiological studies including survivsl, growth and pigment composition at different condition of salinity, temperature and light intensity, and molecular investigations including 16S rRNA gene sequences of the cyanobacterium have been considered. The results indicate the drastic underestimation of the physiological and phylogenetic diversity of these cyanobacteria by the current morphology-based classification and the clear need for new taxa.