The Effects of Light Intensity, Inoculum Size, and Cell Immobilisation on the Treatment of Sago Effluent with Rhodopseudomonas palustris Strain B1

  • Ibrahim, Shaliza (Faculty of Engineering, University of Malaya) ;
  • Vikineswary, S. (Institute of Biological Science, University of Malaya) ;
  • Al-Azad, Sujjat (Borneo Marine Research Institute, Universiti Malaysia Sabah) ;
  • Chong, L.L. (Institute of Biological Science, University of Malaya)
  • Published : 2006.10.30


A study was carried out to determine a suitable light intensity and inoculum size for the growth of Rhodopseudomonas palustris strain B1. The pollution reduction of sago effluent using free and immobilised R. palustris cells was also evaluated. The growth rate in glutamatemalate medium was highest at 4 klux compared to 2.5 and 3 klux. The optimal inoculum size was 10% (v/v). Both the COD and BOD of the sago effluent were reduced by 67% after three days of treatment. The difference in biomass production or BOD and COD removal with higher inoculum sizes of 15 and 20% was minimal. This could be attributed to limited nutrient availability in the substrate. The use of immobilised cells of R. palustris reduced the pollution load 10% less compared to pollution reduction by free cells. Hence, there was no significant difference in using free or immobilised cells for the treatment of sago effluent.


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