The optimization of extracellular α-amylase production by six different Aeromonas and Bacillus species from different soil samples was conducted. The bacterial strains Aeromonas jandaei (accession no. OR136166), Aeromonas hydrophila (Accession no. OR136168), Aeromonas veronii (accession no OR136284), Bacillus subtilis (accession no. OR357659), Bacillus cereus (accession no. OR136189) and Bacillus amyloliquefaciens (accession no. OR244384) underwent biochemical characterization. In this study we have found that among all the three species of Bacillus, Bacillus subtilis showed the maximum enzyme activity and for Aeromonas species it is Aeromonas veronii which displayed the maximum enzyme activity. Bacillus subtilis displayed its maximum α-amylase activity of 8.96 µmol/min at pH 7, and temperature at 35 oC after 24 hours of incubation. And Aeromonas veronii displayed the maximum α-amylase activity of 7.58 µmol/min at pH 7, 35 0C temperature after 24 hours of incubation.