Table 4.

Crude oil-degrading capabilities of the nitrogen-fixing bacteria isolated from the wetland soil

	Incubation period
	1–10 days	11–21 days	21–30 days
Clostridium pasteurianum	+++	+++	+++
Bacillus polymyxa	+++	+++	+++
Azotobacter sp	+++	+++	++
Pseudomonas aeruginosa	+++	+++	+++
Derxia gummusa	++	++	++
Nitrosomonas sp	++	+	+
Nitrobacter sp	++	+	+

+ Scanty growth, ++ Moderate growth, +++ heavy growth