Identification of chondroitin-like molecules from biofilm isolates Exiguobacterium indicum A11 and Lysinibacillus sp. C13.

AIMS: The study aims to investigate whether the bacteria from biofilms can produce chondroitin-like molecules (CLMs). METHODS AND
RESULTS: Chondroitin belongs to the class of glycosaminoglycans. Forty bacteria from biofilms were isolated and screened for the production of glycosaminoglycans. Two isolates A11 and C13 produced 43 and 26 mg l(-1) of chondroitinase AC II degradable glycosaminoglycans, respectively, suggesting the possibility of production of CLMs by them. These isolates were identified using 16S rDNA sequencing technique and fatty acid methyl ester analysis. These were recognized as Exiguobacterium indicum A11 (NCIM 5531) and Lysinibacillus sp. C13 (NCIM 5532) respectively. These strains were also characterized using polar lipid content and biochemical tests. The identity of the glycosaminoglycans produced was further confirmed using agarose gel electrophoresis, fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy.
CONCLUSIONS: Prokaryotic biofilms were found to be a good source of bacteria synthesizing CLMs. Two wild strains producing significant amount of the same were identified and characterized. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study exploring natural biofilms for the production of the therapeutic molecule, chondroitin/glycosaminoglycan. These isolates may be prospective new alternatives to recombinant strains that are reported for the production of chondroitin/glycoaminoglycan at an industrial scale. The production by these wild strains could be commercially attractive if the production is higher and/or can be improved further by strain improvement/process engineering. Further, these are new additions to the scientific literature on glycosaminoglycan-producing micro-organisms.