Sample Weight of residual crude oil (g/l) Percentage biodegradation* (%) Control crude oil 1.0 - B. lichenformis(B.l.) Crude oil + B.l. 0.15 85 Crude oil + B. l. + biosurfactant(1) 0.15 85 Crude oil + B. l. +  CPVAF 0.29 71 Crude oil + B. l. +  CPVA 0.12 88 Rhodococcuserythropolis(R.e.) Crude oil + R.e. 0.14 86 Crude oil + R.e+ biosurfactant(2) 0.12 88 Crude oil + R.e.+  CPVAF 0.30 70 Crude oil + R.e.+  CPVA 0.18 82 Pseudomonas xanthomarina (P.x.) Crude oil + P.x. 0.17 83 Crude oil + P.x.+ biosurfactant(3) 0.13 87 Crude oil + P.x.+  CPVAF 0.20 80 Crude oil +P.x.+  CPVA 0.10 90

*percentage biodegradation = Weight of original oil – wt. of residual / wt. of original oil * 100

Table 1: Percentage biodegradation of petroleum hydrocarbons after treatment with different bacterial strains in presence/ absence of each of biosurfactants and polymers (CPVAF & CPVA) separately