Continuous production of fatty acids from palm olein by immobilized lipase in a two-phase system
Aran H-Kittikun, Asst. Prof., D. of Industrial Biotech., F. of Agro-Industry, PSU.
Poonsuk Prasertsan, Assoc. Prof., D. of Industrial Biotech., F. of Agro-Industry, PSU .
Chatchai Sungpud, D. of Industrial Biotech., F. of Agro-Industry, PSU.
Corresponding e-mail : haran@ratree.psu.ac.th
Grant : Graduate School, PSU., TRF
Published : J American Oil Chemical Society 2000, 77(6) : 599-602
Key words : Accurel, Candida rugosa, fatty acids, immobilized lipase, lipase, palm olein,
two-phase system
Commercial lipases were tested for the ability to hydrolyze palm olein in isooctane in a two-phase system. Lipase OF (from Candida rugosa) showed the highest specitic activity of 209 U/mg protein where 1 U is the amount of lipase enzyme required to produce 1 mmol of fatty acid as palmi-tic acid) per minute. The enzyme was adsorbed completely on Accurel EP 100 (particle size < 200
mml) with 20.5% activity retained. The soluble and the immobilized lipase OF showed optimal acti-vity at the same pH and temperature (pH 6.5-7.5 and 35oC). However, the immobilized lipase had a wider range of pH and higher temperature stability. Continuous hydrolysis of palm olein was per-formed in a packed-bed reactor with 656 U of immobilized enzyme. The substrate (20% palm olein in isooctane) and Tris/maleate buffer were fed concurrently at the flow rates of 0.08 and 0.04 mL/min, respectively. The system gave a degree of hydrolysis (DH) of 90-100% for up to 250 h. A more stable system allowing for more than 300 h operation at DH >95% was achieved by mixing the immobilized enzyme with 1,000-1,500 mm Accurel EP 100 to increase the system porosity and continuous feeding of the aqueous phase recycling from the product mixture. A similar result was also obtained using
1007 U of the immobilized enzyme and 60% palm olein in isooctane fed at 0.06 mL/min.
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