A metagenomic library recombinant clone CAPL3

an Escherichia coli strain generated by transformed with metagenomic library from deep-sea sediments

can efficiently produce cold active lipase. The effects of both temperature and dissolved oxygen (DO) on cold active lipase production by batch culture of metagenomic library recombinant clone (CAPL3) from deep-sea sediment were investigated. First

a two-stage temperature control strategy was developed

in which the temperature was kept at 34℃ for the first 15 h

and then switched to 30℃. The cold active lipase activity and productivity reached 315.2 U·ml

-1

and 8.08 U·ml

-1

·h

-1

respectively

increased by both 14.5% compared to the results obtained with temperature controlled at 30℃. In addition

different DO control modes were conducted

based on the data obtained from the different DO control strategies and analysis of kinetics parameters at different DO levels. A step-wise temperature and DO control strategy were developed to improve li

pase production

i.e.

temperature and DO level were controlled at 34℃

30% during 0-15 h; 30℃

30% during 15-18 h

and 30℃

20% during 18-39 h. With this strategy

the maximum lipase activity reached 354.6 U·ml

-1

at 39 h

which was 28.8% higher than that achieved without temperature and DO control (275.3 U·ml

-1

).