Degradation of 1-butanol by solvent-tolerant Enterobacter sp. VKGH12

Biodegradation of solution-phase 1-butanol by solvent-tolerant Enterobacter sp. VKGH12 (NCIM 5221), which utilizes 1-butanol as its sole source of carbon and energy, was investigated. At an initial loading of 0.4% and 0.8% (v/v) 1-butanol, freely suspended cells degraded 76% and 26%, whereas calcium alginate-immobilized cells degraded 96% and 92% 1-butanol, respectively, in batch cultures. At these loadings, alginate-immobilized cells could be reused for 10 and 7 cycles, respectively, without significant loss in degradation efficiency. A packed-bed reactor containing immobilized cells efficiently degraded 1-butanol at a flow rate of 25–75 ml h−1 at an initial loading of 0.4% (v/v), and could be continuously operated for 10 days at an influent concentration of 0.4% (v/v) 1-butanol without a loss in degradation efficiency. The results suggest the application of immobilized solvent-tolerant bacterium in treatment of solvent waste streams.