DOI: 10.36347/sjavs.2014.v01i02.008

Pages: 90-99

A Cyanobacterium is only oxygenic photosynthetic bacteria having nitrogen fixing ability. Therefore, it is used as biofertilizer in agriculture and grassland fields for improvement of soil fertility. Cyanobacterial strains were isolated from Black Cotton soil by serial dilution method and used to screen out best strain to survive in wet and dry conditions in laboratory. These strains were isolate from agriculture and grasslands soil on the basis of filamentous thalli and presence of heterocyst. Three isolates i.e. DR1, DR2 and NB1 were selected out of six isolates. DR1 and DR2 was heterocystous filament while NB1 was only filamentous strain. Maximum carbon, nitrogen and protein were increased by DR1 and DR2 than NB1 but amount of nitrogen was increased by NB1 was very low in both wet and dry conditions. Results showed that in 60-80% moisture, cyanobacterial strains were well grown and increased amount of carbon, nitrogen and protein. These BGA strains will be used for biofertilizer preparation to improve soil fertility of agriculture and grassland fields.