Fig 4. Comparison of growth curves of D11S-1S grown under three conditions.

The incubation was performed at 37°C, with 5% humidified CO₂. (A). D11S-1S demonstrated a second increase of OD readings after 9 h incubation in 50% human serum. (B). Both human serum and horse serum boosted the growth of D11S-1S within the early 6 h incubation, especially between 3rd and 6th hours based on the extracted total DNA. However, the growth curve based on extracted total DNA also indicated D11S-1S grown in 50% human serum reached the stationary phase after 6 h. (C). In contrast to a second increase of OD readings 9 h after exposure to human serum, the recovered CFU number decreased rapidly after 9-h incubation, indicating bacterial deterioration.