Team:Tec-Monterrey/projectresults/methods

Sac C gene from Zymomonas mobilis was PCR amplified with the primers S1PSF: 5’-GAATT CGCGG CCGCT TCTAG AGGAG CTCAT GTTTA ATTTT AATGC CAGTC GC-3’, S1PSR 5’-CTGCA GCGGC CGCTA CTAGT AGCTA GCGTA TTTGC GACGA TCAGG G-3’. The amplified fragment was cloned in pGEM T Easy Vector. The amplification mixture for 50 mL contained 1U of Platinum Taq HF polymerase (Invitrogen), 60 mM Tris-SO₄, 18 mM Ammonium Sulfate, 0.2 mM for each dNTP, 2 mM MgSO₄, ¿? mM of forward and reverse primers. PCR was performed in an ¿? (¿?) using the following program: ¿? C for ¿? min, 30 cycles of ¿? C for ¿? s, 56.4 C for ¿? s, and 72 C for ¿? min, and finally an extension step at 72 C for ¿? min. The PCR product cloned in pGEM T Easy Vector was added to the registry (BBa_K633003) and the product was cloned in the plasmid pSB1C3 and added to the registry (BBa_ ¿?).

The ompA+sacC construction was generated by joining the biobricks of a promoter (araC BBa_I13458 and P_BAD BBa_K206000), RBS (BBa_B0034), lpp+ompA (BBa_K103006) with the biobrick standard assembly protocol (¿cita?). The expected DNA fragment size (XX bp) of the ompA + sacC construct was confirmed by several restriction endonuclease reactions and agarose gel electrophoresis, and used to transform the E.coli strins BL21SI, Rosetta Gami, XL1 Blue, C43 and BW27783.

The E. coli strains containing the ompA+sacC construct and non-trasnsformed strains as negative controls were cultured with 6 mL of media M9 with glycerol as carbon source at an initial optical density at 600 nm (OD₆₀₀) of 0.1. The batch cultures were performed at 37C until the OD₆₀₀ of 0.6 was attained. Then, the expression was induced with 0.1mM of L-arabinose and the temperature of postinduction was changed to 15C. Culture samples collected from the bioreactor were harvested by centrifugation. The half volume was used for the whole cell assay and the other half was processed with Clontech x-Tractor kit to obtain soluble and insoluble fraction of each strain. Both fractions were separated by 10% SDS-PAGE and visualized with X % (w/v) Coomassie Brilliant Blue R250.