Fig. 3

FTIR spectrum for EPS derived from B. cereus cultivated under Zn metal stress at different concentrations (a) control (b) 10 mg L^− 1 (c) 20 mg L^− 1 (d) 30 mg L^− 1 (e) 40 mg L^− 1 (f) 50 mg L^− 1, indicating functional groups detected. The peaks indicate O-H stretching (3650–3200 cm^− 1), C-H stretching (3000–2850 cm^− 1), C=C stretching (1680–1450 cm^− 1), −CH₂ bending (1500–1320 cm^− 1) and C-O stretching (1300–1000 cm^− 1)