4.2. Error-Prone PCR and Generation of Mutant Library

The mutant library was generated via error-prone PCR using the GeneMorph^® II Random Mutagenesis kit (Stratagene, La Jolla, CA, USA) according to the manufacturer’s instructions. The plasmid of rT-M386 was used as a template with forward (5′-CGGAATTCGCAGCAGCAATGGCGCAAGCTCAATATAAAAAT-3′) and reverse primers (5′-CCGCTCGAGTCACTAACCATCTAGCTCTTCGACTTTCAA-3′). The amplified PCR products and pGEX-6P-1 vector were double digested, ligated and then transformed into E. coli strain BL21 (DE3). The transformed cells were plated on a tributyrin-ampicillin agar plate.