Analysis of over-expression of different clones at 37 °C using SDS-PAGE (12.5%). Lane 1, crude extract of pETTm0548; lane 2, CFE of pETTm0548; lane 3, heat-treated CFE of pETTm0548; lane 4, crude extract of pETTm0549; lane 5, CFE of pETTm0549; lane 6, heat-treated CFE of pETTm0549; lane 7, crude extract of pETTm0548/9; lane 8, CFE of pETTm0548/9; lane 9, heat-treated CFE of pETTm0548/9; M: BLUeye pre-stained Protein Ladder (Froggibio, ON, Canada), the arrows indicate the position of the recombinant protein band; approximately 15 µg protein was loaded per lane.