Table 2 Control experiments for asphaltene biotransformation

Controls for determination of asphaltene biotransformation

Abiotic control

Model oil (asphaltene in hexadecane or HMN) and MSM supplemented with sucrose but uninoculated

0

0.00

Asphaltene biotransformation without sucrose

MSM without sucrose, Asphaltene in hexadecane and Microbial consortium

2

28.57

Effect of sucrose addition on biotransformation of asphaltene

MSM with sucrose, Asphaltene in hexadecane and Microbial consortium

12.32

72.64

Hexadecane biodegradation by the microbial consortium

1

MSM without sucrose, Hexadecane and Microbial consortium

2.92

NA

Effect of sucrose addition on hexadecane biodegradation

2

MSM supplemented with sucrose, Hexadecane and Microbial consortium

12.56

NA

Microbial biotransformation of crystalline asphaltene

3

MSM without sucrose, 11.25 g/l crystalline asphaltene and microbial consortium

2.34

7.65

Asphaltene biotransformation experiment in which ammonium oxalate was replaced by ammonium chloride in MSM and supplemented with sucrose

4

MSM containing ammonium chloride and supplemented with sucrose, Asphaltene in hexadecane and Microbial consortium

10.33

69.13

Effect of dead biomass on extraction of residual asphaltene

5 Biotic control

MSM without sucrose, Asphaltene in hexadecane and dead microbial consortium

14.52

0.35

Asphaltene biotransformation experiment with ammonium oxalate as carbon source

6

MSM containing ammonium oxalate but no sucrose, Asphaltene in hexadecane and Microbial consortium

2.21

28.54

Heptamethylnonane utilization by microbial consortium

7a

MSM without sucrose, Heptamethylnonane and Microbial consortium

0.64

NA

Effect of sucrose addition on HMN utilization

7b

MSM with sucrose, Heptamethylnonane and Microbial consortium

8.97

NA

Asphaltene biotransformation experiment using HMN as inert carrier phase and media supplemented with sucrose

8

MSM supplemented with sucrose, Asphaltene in Heptamethylnonane and Microbial consortium

8.86

70.35