Fig. 1

Volumetric hydrogen productivity (Q_H2) and substrate consumption rate of pure culture of C. kronotskyensis. Q_H2, bar graph (mmol L⁻¹ h⁻¹) and substrate consumption rate, line graph (mmol L⁻¹ h⁻¹). Case A (without carriers, dotted bar, open circle); Case B (with acrylic fibres, vertical line, open square); Case C (with acrylic fibres and chitosan, diagonal line, open diamond); and Case D (with chitosan, brick, open triangle)