Lipase Pilot-Scale Production Process

Spray drying and boiling granulating process are key downstream processes in the industrial utilization of lipase, which have important scientific and practical value. Candida sp.L 11-01 is an advanced lipase producing strain. Fermentation broth showed hrydrolytic activity with 16885 U/mL with soybean meal as nitrogen source. Nitrogen source was optimized as well as the semi continuous fermentation was proceeded in order to reduce the fermentation cost. The highest hrydrolytic activity could only reach to 13000 U/mL when using corn starch as nitrogen source. Corn starch is soluble without pretreatment, which partly saved the fermentation cost. Semi-continuous fermentation obviously shortened the fermentation period from 120h to nearly 63 h and showed an producing stability.300 L fermentation differed from the 7 L one, of which both the activity growth and the biomass growth slowed down. Lipase hrydrolytic activity was more than 10000 U/mL at 168h and 216h.Different protectants were added to prevent supernatant lipase from inactivation at room temperature. D-trehalose had an positive effect on lipase at 25?. The best inlet and outlet temperatures of spray drying was 160? and 70?, respectively. Adding sodium alginate, ?-cyclodextrin resulted in hydrolysis activity increasing from an initial activity of 49624 U/g respectively to 55123 U/g and 55885 U/g. PEG6000, ?-cyclodextrin and gelatin could partly avoid lipase powder from sticking the wall. The optimal PEG6000 additive amount was 4-6%(w/v).The final protectant formula (w/v):4% PEG6000,0.5% ?-cyclodextrin and 0.5% gelatin. Enlarge experiment of 10 kg supernatant in spray dryer confirmed the operational continuity in the presence of formula protectant. Powder without protectants contributed to only 20% esterification conversion rate while the one with protectants increased to 49% esterification conversion rate, which was close to 55% of the commercial lipase powder.Boiling granulating process gived lipase good sedimentation performance.33%(w/v) maltodextrin solution satisfied rapid granulating in boiling granulating process. The proper inlet/outlet temperature of granulation could be 70-80?/26-35?. Particles without embedding showed an excellent esterification of more than 90% conversion, but suffered from a sharp decline when embeded. Immobilized lipase particles had an hydrolysis activity of 2110 U/g, and an 47% conversion rate when its adding amount reached 30%(w/v) of oleic acid quality.