Studies on fluidized bed column reactor for the substrate conversion using immobilised extracellular alkaline lipase of isolated strain of Serratia sp (C4)

Lipase producing microbial strain Serratia sp(C4) was isolated from spoiled coconut using olive oil medium.The isolate C4 was shown the maximum enzyme activity of 9.4I.U/ml. The extracellular lipase was alkaline in nature. The maximum specific activity of the partially purified lipase by using ammonium sulphate as suitable precipitating agent was found to be 16.16I.U/mg. The partially purified lipase was immobilised by 2% calcium chloride solution followed by treatment with intermolecular cross linking agent glutaraldehyde solution. The maximum specific activity of the immobilised lipase before and after treatment with glutaraldehyde solution at an optimum concentration level of 1% and optimum contact time of 30sec were estimated as 10.41I.U/mg and 12.50I.U/mg. The maximum activity retention of the immobilised lipase before and after treatment with glutaraldehyde solution under the same conditions were determined as 64.41% and 77.35% respectively. The maximum substrate conversion was found to be 26% at the fluidized bed height of 85mm and after 7hr of operation in continuous fluidized bed column reactor. Key words: Lipase,immobilisation,glutaraldehyde,activity retention,fluidized bed reactor