Journal of Microbiology and Biotechnology

The Korean Society for Microbiology and Biotechnology (한국미생물·생명공학회)
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Production and Rheological Properties of Bioflocculant Produced by Bacillus sp. DP-152

  • SUH, HYUN-HYO (Department of Environment Engineering, Chinju National University) ;
  • SEONG-HOON MOON (Environmental Microbiology Research Unit, Korea Research Institute of Bioscience and Biotechnology) ;
  • HEE-SIK KIM (Environmental Microbiology Research Unit, Korea Research Institute of Bioscience and Biotechnology) ;
  • HYOUNG-KAB KIM (Department of Environment Engineering, Chinju National University) ;
  • GEE-ILL JUN (Department of Environment Engineering, Chinju National University) ;
  • HYUN-GEOUN PARK (Department of Environment Engineering, Chinju National University) ;
  • DAE-OOK KANG (Cellular Response Modifiers Research Unit, Korea Research Institute of Bioscience and Biotechnology) ;
  • HEE-MOCK OH (Environmental Microbiology Research Unit, Korea Research Institute of Bioscience and Biotechnology) ;
  • BYUNG-DAE YOON (Environmental Microbiology Research Unit, Korea Research Institute of Bioscience and Biotechnology)
  • Published : 1998.12.01
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Abstract

The culture conditions for Bacillus sp. DP-152 in the flask were investigated for the production of polysaccharide locculant, DP-152. The optimum pH and temperature for the locculant production were 8.0 and $30^{\circ}C$, respectively. The avorable substrates for flocculant production were soluble tarch and ammonium nitrate. The medium composition was optimized as follows: 30 g soluble starch, 0.75 g $NH_4NO_3,\; 2.0g\; K_2\;HPO_4,\; 0.1\; g KH_2PO_4,\; 0.2g\; MgSO_4.\; 7H_2O,\; and\; 0.2g\; MnSO_4~5H_2O$ in 11 of distilled water. Under this optimized condition, flocculating activity has been improved 4-fold compared with that of the basal medium. In the culture flask, the highest flocculating activity was obtained after 70 h of cultivation and the amount of bioflocculant DP-152 yielded was 12.4 g/$\ell$. The solution of bioflocculant DP-152 showed non-Newtonian characteristics. Bioflocculant DP-152 exhibited apparently higher viscosity at all concentrations compared to that of zooglan (from Zoogloea ramigera), and it was stable over a wide range of temperatures and pHs.

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