Genomic analysis of carbon dioxide sequestering bacterium for exopolysaccharides production

Sci Rep. 2019 Mar 12;9(1):4270. doi: 10.1038/s41598-019-41052-0.

Abstract

In the present study, genomic analysis of a previously reported carbon dioxide (CO2) sequestering bacterium Serratia sp. ISTD04 was performed along with exopolysaccharide (EPS) production. Genomic analysis identified key and accessory enzymes responsible for CO2 sequestration. EPS synthesis genes were discovered in the genome and identified 8 putative clusters responsible for lipopolysaccharide, stewartan, emulsan, polysaccharide B, capsular polysaccharide and fatty acid-saccharide production. The production of EPS was found to be 0.88 ± 0.08, 1.25 ± 0.13 and 1.44 ± 0.10 g L-1 on glucose, bicarbonate (NaHCO3) and NaHCO3 plus glucose respectively at pH 7.8. After optimizing process parameters, the EPS production increased more than 3 folds. The morphology of strain and elemental composition of EPS was characterized by SEM-EDX. The functional groups, monomer composition, linkage analysis and structure of purified EPS was characterized by FTIR, GC-MS and 1H and 13C NMR. Glucose, galactose, mannose and glucosamine are the monomers detected in the EPS. EPS was further applied for bioflocculation (kaolin test) and dye removal. The EPS showed 68% ± 0.9 flocculating activity and decolorized cationic dye acridine orange (80%) and crystal violet (95%). The results highlight CO2 sequestration and EPS production potential of Serratia sp. ISTD04 that can be harnessed in future.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Biosynthetic Pathways / genetics
  • Carbon Dioxide / metabolism*
  • Climate Change
  • Flocculation
  • Genome, Bacterial / genetics
  • Genomics
  • Glucose / metabolism
  • Industrial Microbiology / methods*
  • Multigene Family / genetics
  • Polysaccharides, Bacterial / biosynthesis*
  • Polysaccharides, Bacterial / isolation & purification
  • Serratia / enzymology
  • Serratia / genetics*
  • Sodium Bicarbonate / metabolism
  • Spectroscopy, Fourier Transform Infrared

Substances

  • Bacterial Proteins
  • Polysaccharides, Bacterial
  • Carbon Dioxide
  • Sodium Bicarbonate
  • Glucose