Variations in (a) hydraulic conductivity of coarse sands treated with bacterial cells and enzymes with time. ◊ (⧫) MIBF without back-pressure at sucrose concentration of 40 g/l; ● MIBF with back-pressure at sucrose concentration of 40 g/l; ○ MIBF with back-pressure at sucrose concentration of 160 g/l; ■ (□) EIBF without back-pressure at sucrose concentration of 40 g/l. The power exponent n denotes the Archie's saturation exponent, which implies the extent of pore clogging and the level of permeability reduction by biopolymer. A greater n value indicates a lower K/K₀ and the greater reduction in hydraulic conductivity