Fig. 3

The growth kinetics of recombinant E. coli DH5α and BL21 (DE3) (A). Cultures of E. coli DH5α showed higher growth density and rate as incubation temperature declined, achieving the highest growth rate at 25 °C. Non-linear regression analysis is demonstrated to show the inverse correlation (r = − 0.9383, P = 0.0091) between growth rate and temperature. Unlike DH5α, cultures of BL21 (DE3) showed a positive correlation with growth temperature (r = 0.9779, P = 0.002) (B), where they grew faster in elevated temperatures reaching the maximum at 37 °C (C)