Molecular identification of chitinolytic bacteria with potential application in biofuel production

One of the most important issues in biofuel production by microorganisms is the cost of raw materials for fermentation processes. Chitin is the second mostabundant biopolymer on the earth and can be used as cheap and renewable carbon source in fermentation technology. However chitin could not be appliedby the most ethanol producing microorganisms. Chitinolytic microorganisms which could covert the non-consumable chitin to N-acetyl D-glucosamine arevery interesting in biofuel production. A total of 300 bacterial isolates were obtained from different depth of Caspian Sea. The clear zones around coloniesafter 15 days incubation of cultures containing 2.5% (w/v) colloidal chitin at 20°C indicated qualitative chitinase activity. 12 strains were identified as chitinolytic bacteria. As the secondary screening procedure, chitinase activities of these strains were measured colorimetrically. A total of 9 strains can produced definitely amount of N-acetyl D-glucosamine. These strains were identified by molecular approach. The genomic DNA of these strains was extracted and the 16S rRNA gene was amplified by the universal 27F and 1492R primers. Phylogenetic analysis based on 16S rRNA gene sequences revealed that these strains are the members of the following genera: Paenibacillus, Pseudoalteromonas, Aeromonase, Stenotrophomonas, Pseudomonas and Rheinheimera (4 strains). These strains are good candidate for production of consumable raw materials in biofuel fermentation. Optimization of chitinanse production and characterization of the enzymes are in progress.

Keywords:

Bacteria , Chitin , Chitinase , Biofuel , Caspian Sea