title: Screening of Alginate Lyase-Producing Bacteria and Optimization of Media Compositions for Extracellular Alginate Lyase Production.
abstract: BACKGROUND
  Alginate is a linear polysaccharide consisting of guluronate (polyG) and mannuronate (polyM) subunits.
  
  
  METHODS
  In the initial screening of alginate-degrading bacteria from soil, 10 isolates were able to grow on minimal medium containing alginate. The optimization of cell growth and alginate lyase (algL) production was carried out by the addition of 0.8% alginate and 0.2-0.3 M NaCl to the culture medium. Of 10 isolates, one was selected based on its fast growth rate on minimal 9 medium containing 0.4% sodium alginate. The selected bacterium, identified based on morphological and biochemical characteristics as well as 16S rDNA sequence data, was confirmed to be an isolate belonging to the genus Bacillus and designated as Bacillus sp. TAG8. Resuls: The results showed the ability of Bacillus sp. TAG8 to utilize alginate as a sole carbon source. Bacillus sp. TAG8 growth and algL production were augmented with an increase in sodium alginate concentration and also by the addition of 0.2-0.3 M NaCl. Molecular analysis of TAG8 algL gene showed 99% sequence identity with algL of Pseudomonas aeruginosa PAO1. algL produced by Bacillus sp. TAG8 cleaved both polyM and polyG blocks in alginate molecule as well as acetylated alginate residues, confirming the bifunctionality of the isolated lyase.
  
  
  CONCLUSIONS
  The identification of novel algL genes from microbial communities constitutes a new approach for exploring lyases with specific activity against bacterial alginates and may thus contribute to the eradication of persistent biofilms from clinical samples.
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran.
authors.forename: Hadis
authors.initials: H
authors.lastname: Tavafi
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran.
authors.forename: Ahya
authors.initials: A
authors.lastname: Abdi-Ali
authors.affiliation: Department of Biotechnology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran.
authors.forename: Parinaz
authors.initials: P
authors.lastname: Ghadam
authors.affiliation: Department of Biotechnology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Gharavi
mesh_terms: D000464:Alginates / Q000378:metabolism*; D001407:Bacillus / Q000201:enzymology / Q000302:isolation & purification / Q000378:metabolism; D018441:Biofilms; D004275:DNA, Ribosomal / Q000235:genetics; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D011133:Polysaccharide-Lyases / Q000096:biosynthesis*; D011550:Pseudomonas aeruginosa / Q000201:enzymology; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D000464:Alginates; D004275:DNA, Ribosomal; D006603:Hexuronic Acids; D012336:RNA, Ribosomal, 16S; D020723:Glucuronic Acid; D011133:Polysaccharide-Lyases; C016158:poly(beta-D-mannuronate) lyase
keywords: Alginate; Alginate lyase; Bacillus spp.; Pseudomonas biofilm