Production of lipase by high cell density fed-batch culture of Candida cylindracea.
Candida cylindracea NRRL Y-17506 was grown to produce extracellular lipase from oleic acid as a carbon source. Through flask cultures, it was found that the optimum initial oleic acid concentration for cell growth was 20 g l(-1). However, high initial concentrations of oleic acid up to 50 g l(-1) were not inhibitory. The highest extracellular lipase activity obtained in flask culture was 3.0 U ml(-1) after 48 h with 5 g l(-1) of initial oleic acid concentration. Fed-batch cultures (intermittent and stepwise feeding) were carried out to improve cell concentration and lipase activity. For the intermittent feeding fed-batch culture, the final cell concentration was 52 g l(-1) and the extracellular lipase activity was 6.3 U ml(-1) at 138.5 h. Stepwise feeding fed-batch cultures were carried out to simulate an exponential feeding and to investigate the effects of specific growth rate (0.02, 0.04 and 0.08 h(-1)) on cell growth and lipase production. The highest final cell concentration obtained was 90 g l(-1) when the set point of specific growth rate (mu(set)) was 0.02 h(-1). High specific growth rate (0.04 and 0.08 h(-1)) decreased extracellular lipase production in the later part of fed-batch cultures due to build-up of the oleic acid oversupplied. The highest extracellular lipase activity was 23.7 U ml(-1) when mu(set) was 0.02 h(-1), while the highest lipase productivity was 0.31 U ml(-1) h(-1) at mu(set) of 0.08 h(-1).
Microbial Genomics and Bioprocessing Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, 1815 North University Street, Peoria, IL 61604, USA.
Beom Soo
BS
Kim
Ching T
CT
Hou
D019149:Bioreactors / Q000382:microbiology*; D002175:Candida / Q000502:physiology*; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation; D003198:Computer Simulation; D008049:Lipase / Q000096:biosynthesis*; D008954:Models, Biological; D019301:Oleic Acid / Q000378:metabolism*; D010865:Pilot Projects
D019301:Oleic Acid; D008049:Lipase