Figure 2From: Efficient production of l-lactic acid by an engineered Thermoanaerobacterium aotearoensewith broad substrate specificityScreening and confirmation of pta and ack genes knockout. (A) polymerase chain reaction (PCR) screening using genomic DNA as template. Lane 1, 1 kb DNA ladder (TaKaRa), Lane 2, SCUT27, Lane 3&4, positive isolates. (B) Southern blot analysis of genomic DNA from wild type SCUT27 (Lane 1) and the pta and ack deletion clones, LA1002 (Lane 2) digested with Pst I. The probe with the expected sizes of 486 bp (position shown in Figure 1), hybridized to one 1.2 kb fragment of wild type DNA, and to one 2.2 kb fragment of the mutant DNA.Back to article page