Fig. 5

Growth revival assay of E. coli SUBE01 at above critical growth temperature (47 °C). Effect of high temperature on growth of E. coli: a impact on cell turbidity and influence on the formation of CFUs, b and the demonstration of loss of cell culturability by means of spot test c upon supplementation with organic and inorganic supplement. Cells were grown in minimal agar at 47 °C up to 72 h and after 10 h of growth organic supplement (the extracellular fractions of Bacillus species) and inorganic supplement (20 mM MgSO₄ with 5 mM EDTA) were added and untreated cells were referred as control. At every 12 h interval, cells were diluted and grown in minimal agar at 37 °C for 24 h. A growth revival was observed at 47 °C (c, d), when cells were grown with inorganic supplement. All experiments were carried out three times and the standard deviations for all data have been indicated by error bars