title: Antimicrobial assay and genetic screening of selected freshwater Cyanobacteria and identification of a biomolecule dihydro-2H-pyran-2-one derivative.
abstract: OBJECTIVE
  Explorations of freshwater Cyanobacteria as antimicrobial (bacteria, fungi and methicillin-resistant Staphylococcus aureus (MRSA) strains) drug resource using bioassay, NRPS (non-ribosomal polypeptide synthetase) and PKS (polyketide synthase) genes, as well as in silico approach.
  
  
  RESULTS
  We have bioassayed the extracts of Phormidium CCC727, Geitlerinema CCC728, Arthrospira CCC729, Leptolyngbya CCC732, Phormidium CCC730, Phormidium CCC731 against six pathogenic bacteria comprising Gram (+ve): S. aureus including seven clinical MRSA and Enterococcus faecalis, Gram (-ve): Escherichia coli, Salmonella Typhimurium, Klebsiella pneumoniae and Shigella boydii along with non-pathogenic Enterobacter aerogenes as well as fungal strains (Cryptococcus neoformans and Candida albicans, C. krusei, C. tropicalis and Aspergillus niger) exhibiting antimicrobial potential. The NRPS and PKS genes of the target strains were also amplified and sequenced. The putative protein structures were predicted using bioinformatics approach.
  
  
  CONCLUSIONS
  PKS gene expression indicated β keto-acyl synthase as one of the important active domains in the biomolecules related to antitumour and antifungal group. The simultaneous identification of the biomolecule (dihydro-2H-pyran-2-one derivative) was also inferred spectroscopically.
  
  
  CONCLUSIONS
  Freshwater Cyanobacteria are prolific producers of secondary metabolite(s) that may act as the antimicrobial drug resource in addition to their much explored marine counterpart.
authors.affiliation: Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
authors.forename: A
authors.initials: A
authors.lastname: Srivastava
authors.affiliation: School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
authors.forename: V K
authors.initials: VK
authors.lastname: Singh
authors.affiliation: Council of Scientific and Industrial Research - Indian Institute of Toxicology Research, Lucknow, Uttar Pradesh, India.
authors.forename: S
authors.initials: S
authors.lastname: Patnaik
authors.affiliation: Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
authors.forename: J
authors.initials: J
authors.lastname: Tripathi
authors.affiliation: Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
authors.forename: P
authors.initials: P
authors.lastname: Singh
authors.affiliation: Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
authors.forename: G
authors.initials: G
authors.lastname: Nath
authors.affiliation: Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
authors.forename: R K
authors.initials: RK
authors.lastname: Asthana
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D003198:Computer Simulation; D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D005618:Fresh Water / Q000382:microbiology; D005658:Fungi / Q000187:drug effects; D005820:Genetic Testing; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D044162:Parathyroid Hormone-Related Protein / Q000008:administration & dosage / Q000494:pharmacology*; D010453:Peptide Synthases / Q000737:chemistry / Q000235:genetics; D048630:Polyketide Synthases / Q000737:chemistry / Q000235:genetics; D011753:Pyrones / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D044162:Parathyroid Hormone-Related Protein; D011753:Pyrones; D048630:Polyketide Synthases; D010453:Peptide Synthases
keywords: Cyanobacteria; NRPS-PKS genes; antimicrobial bioassay; bioinformatic approach; spectroscopic analysis