TABLE 2.
Purification steps of recombinant α-amylases secreted by L. plantarum strainsa
| α-Amylase-producing strain | Purification step | Vol (ml) | Total protein (mg) | Total activity (U) | Sp act (U · mg−1) | Purification (fold) | Yield (%) |
|---|---|---|---|---|---|---|---|
| L. plantarum(pLPCR2-3) | Culture supernatant | 150 | 24 | 1,345 | 56 | 1 | 100 |
| Affinity chromatography | 5 | 0.2 | 930 | 4,076 | 72 | 69 | |
| L. plantarum(pLPCR2-3ΔB/X) | Culture supernatant | 1,000 | 168 | 9,864 | 58 | 1 | 100 |
| (NH4)2SO4 precipitate and ultrafiltration | 4 | 31 | 6,003 | 192 | 3 | 61 | |
| Gel filtration | 2 | 0.5 | 409 | 766 | 13 | 4 | |
| Ultrafiltration and concentration | 0.1 | 0.1 | 299 | 3,511 | 60 | 3 |
a
Data are from 1.5 liters of L. plantarum culture supernatant. Activity was determined as described in Materials and Methods, using soluble starch as a substrate. Protein concentrations were determined with the Bio-Rad protein assay.