Assessment of Cyanobacterial Biodiversity Through Molecular Approaches and Possible Exploitation for Value Addition
Cyanobacteria a diverse group of photosynthetic prokaryotes often play central roles in carbon and nitrogen assimilation which makes their environment productive. Molecular approaches have been divided into 2 classes: PCR independent and PCR based approaches. The former includes guanine plus cytosine (G+C) content, nucleic acid re-association and hybridization and DNA microarrays, the latter basically uses DNA cloning and sequencing, DGGE (denaturing gradient gel electrophoresis), TGGE (Temperature gradient gel electrophoresis), SSCP (single strand conformation polymorphism) RFLP (restriction fragment length polymorphism), ARDRA (amplified ribosomal DNA restriction analysis), T-RFLP (terminal restriction fragment length polymorphism), RISA (ribosomal intergenic spacer analysis) ARISA (automated ribosomal intergenic spacer analysis) and RAPD (random amplified polymorphic DNA). Molecular assessment of cyanobacteria frequently uses markers like16S rDNA, phycocyanin locus, nif gene, rpo gene, ITS region etc. Genetic diversity was assessed using the banding patterns of repetitive DNA sequences including the short tandemly repeated repetitive (STRR) sequences and long tandemly repeated repetive (LTRR) sequences that are present in the cyanobacterial genome. The phylogenetic relationships inferred from comparison of the STRR sequences generally supported the traditional classification based on morphological criteria.
Biodiversity; Molecular characterization; Value addition
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[ISSN : 0975-2773(Print)]