MOESM5 of Improved secretory expression of lignocellulolytic enzymes in Kluyveromyces marxianus by promoter and signal sequence engineering

Additional file 5: Figure S3. Purification and specific activity of RuCelA. Transformants containing pZP52 were grown in 5L fermentor for 56 h. 200 mL culture was centrifuged at 12, 000 rpm for 30 min at 4 degree. The supernatant was purified by the ion exchange chromatography and gel filtration in the same procedure as described for Est1E. Peak of RuCelA was eluted at 16.3 mL. The protein concentration of purified RuCelA was 55 Îźg/mL, as measured by a BCA Protein Assay Kit. The enzymatic activity of purified RuCelA was 3.6 U/mL and the specific activity of RuCelA was 65 U/mg. Supernatant of the culture, samples after purification by ion exchange and gel filtration were subjected to SDS-PAGE